:idea: About distributor gear wear (UPDATED!!)

[jeepsr4ever]

Here is a list of things that can cause distributor and cam gear wear.



1. Oiling holes throught the large timing gear, the groove for the oiling hole must be at 2:00 from the keyway, also all passages must be clear.

2. Cam bearing at the front of the block must have a groove in it, this sends oil through the cam at all orientation and rotation of the camshaft.

3. The cam must have a 90 degree oiling hole setup to feed the timing gear and must be free from casting obstruction.

4. Cam gear must be matched to the distributor gear. Their are 2 types of cam gears out there and at least 3 types of distributor gears, they CANNOT be mismatched, replacing just the cam gear will cause big problems.

5. The timing cover: The oil pump drive gear's shaft that connects to the distributor goes through a hole in the timing cover, this is a precision hole and if tapered can cause distributor gear wear through chatter.

6. Oil pump gears: Using longer than stock or poorly made after market gears can cause chatter, binding or premature wear of the oil pump drive gear's shaft hole. When you install a aftermarket kit that comes with new gears the idler gear pin MUST be longer. The cam and distributor gears are only rated at a certain torqueload. Some of the new gears available as of 4-22-05 are now hardened (both gears) and can withstand greater pressures

7. Oil filter.......Yes oil filters can cause premature dizzy and cam gear wear. If you run the wrong oil (too heavy) or a filter that gets clogged early or a filter that isnt a high flow you open up your oil filter bypass and not only send dirty oil through your motor, you also exerpt a high amount of pressure on the oil pump and that alone can cause gear wear, this happens mostly on start up. In late 87 chrysler got rid of the oil filter bypass on the oil filter adaptor, after market oil filter adaptors also have this cast in. Beware that if you use a high pressure oil pump spring without a oil filter bypass you run the risk of ballooning your filter.

8. Cam walk: Cam walk can be attributed to a cocked or poorly place cam plug (large freeze plug that hold the cam from leaving the rear of the block. Also cam walk can be caused by bad lifters, worn cam bearings, cam bearings installed improperly, or a poorly ground cam and in some cases a new cam that gets flattened on startup

9. Cam walk can also be attributed to lack of relief holes in the back of the cam, you see pressure can increase between the end of cam and cam plug, most of these cam must be checked, we have 3 in here with no relief holes...............dang summit

10. The retainer washer for the front of the cam that holds the distributor gear must also provide a positive seal for proper oiling. Off the shelf washers can sometimes have nicks or be convex or concave which to factory torque specs can lead to a loss of oil in front of the camshaft.

11. The installation of the timing cover without locator pins or worn location holes will cause a mis-orientation of the thrust on the distributor gear and eventually may result in a broken or heavily worn set.

12. Early Crown timing covers that were not checked for proper dimensional tolerance can attribute to up to 100% of the fast gear wear. Even today vendors should check for proper alingment.


I have seen a AMC V8 go 210,000mls without any cam walk and very little gear wear. I have also seen a AMC V8 go 2 miles and eat the gears. The factory engineers knew all this and they put these motors together accordingly. Building a AMC V8 can be a expensive build and its a dirty dirty shame to have something like a cam or distributor gear go out, this can cause Major scoring on the oil pump cavity and also can cause the oil filter bypass to open and voila, roached bearings. Hope these hints help anyone out who is building a AMCV8.

-MC

[fuzz401]

there must be a slight indentation on the back of the timeing cam gear

[Elliott]

Nice write-up, very nice. From what else I've read, incorrectly ground cams have at least two issues: 1) wrong journal dimensions and 2) lack of lobe taper that keeps the cam back in the block. I wouldn't rule out the possiblity that some will go flat due to incorrect sintering process or simply loss of tempering during a faulty grind.

[fuzz401]

cast timming cam gear
http://img2.photobucket.com/albums/v11/fuzz401/104_0420.jpg

old style roll master cam gear
http://img2.photobucket.com/albums/v11/fuzz401/104_0421.jpg
http://img2.photobucket.com/albums/v11/fuzz401/104_0418.jpg

new style roll master with bearing cam gear
http://img2.photobucket.com/albums/v11/fuzz401/104_0422.jpg

[rollen dean montoya]

does this apply to the I-6 258?

[jeepsr4ever]

nope the rules change dramatically for the sixes

[Diagram1]

I recently got a "Proform" HEI type distributor for my 73 CJ5 w/304 and have heard you shouldnt match a new drive gear with a old cam gear and vis versa. I was thinking of removing the old drive gear and putting it on the new distibutor rather than rebuilding the block. Is this and option I have? If so, is there anything I should be particularly weary about?

[jeepsr4ever]

Welcome aboard! :t:

Its true their are 2 different profiles on the dizzy gears these days. One is from the oem gear the other is from the import dizzy gear (the superior one) believe it or not. you may or may not be able to get away with doing that. You cant even take your old one and install it on your new dizzy as their are 13 teeth on each gear and MUST be matched. But lots of guys have just nstalled a new dizzy gear with success...I have had moderate success.

[fuzz401]

found this on the amc forum
More cam/distributor gear issues
From: Randy Guynn <amx69@swbell.net>
Date: Wednesday, February 18, 2004 08:23

This old bugaboo is rearing it's ugly head yet again. The latest
casualty comes from mis-matched parts. The cam did not have a groove in
the front journal, and the front cam bearing was not a grooved type.
This shuts off all oil to the front of the engine which in turn burns
the gears up.

Anyone & everyone in the AMC hobby needs to be fully aware of how the
gears recieve oil. They also need to understasnd the entire system of
parts , what is correct, what is not, in order the be sure they are not
going to have troubles in this area.

When the engines starts and oil pressure develops, the very first part
of the engine to recieve oil is the front cam journal. The oil splits
the path at that point and part goes thru the timing gears, the
remainder goes to the rest of the engine. The oil continues thru each
cam journal where it splits and oils the upper end and the lower end.

Back to the very first spot that sees the oil, the front cam journal.
#1, the cam, & or Bearing MUST have a 360 degree groove. No groove, then
the only time oil will get to the gears is once every 360 degrees, when
the oil holes line up, the gear will get a small squirt of oil and that
is it.
#2,The cam has a hole in the side of the front journal and it also has a
hole in the face of the journal. These two holes MUST intersect. If
these two holes do not join, then NO OIL ever gets to the timing gears.
#3,The upper timing gear has a pocket machined or cast into the rear of
the sprocket. This pocket MUST line up with the hole in the face of the
cam journal. If the pocket does not line up, no oil will go to the gears.
#4. The upper timing gear needs a heavy chamfer completely around the
I.D. of the hole where is slides on the camshaft. This chamfer is not
there to aid in fitting the cam easier, it is there to supply a route
for the oil to go. No chamfer, no oil gets to the gears.
#5, The upper timing gear also has two slots. One slot is for the keyway
that holds it to the cam, the other slot is for oil transfer. The oil
transfer slot MUST be free and open, no casting flash to block oil.
#6 Next the fuel pump eccentric comes into play. It will also have two
slots. One for the keyway, one fore the oil transfer slot.
#7, finally we come to the cam gear which drives the distributor. This
gear too has two slots. Again one for the keyway, the other for oil
transfer. The transfer slot must be open and lined up with all the other
oil transfers so there is an open groove which will supply the oil to
the gears.
#8, the Cam gear MUST have 4 small holes around the outside diameter of
the gears. 3 of these small holes are on the smae plane, lined up with
each other. The one hole will be offset. If this one hole is not offset,
then the keyway will block the oil going to it.

There are other issues at play here such as mis-machined parts, cam
walk, bad gears, etc. However, no matter how good of quality parts used,
if the oil cannot get to the gears then the gears will be burned/eaten up.

Maybe you are just freshing up your engine and think everything is just
fine, and it might be. But, just change ONE part in the ''oil circuit''
and that part could block oil from getting to the gears. This oiling
issue is VERY, VERY important. Everytime you assemble am AMC V8 you
should look EVERY piece over that makes up the oil delivery to the
gears. If you slack off here you are just asking for trouble when it
comes to AMC V8 engines.

[fuzz401]

http://img2.photobucket.com/albums/v11/fuzz401/104_0458.jpg

http://img2.photobucket.com/albums/v11/fuzz401/104_0457.jpg

[jeepsr4ever]

Great pic fuzz! I talk to Randy from time to time. He is a good guy and very knowledgable :t:

I have heard myths of fuel pump eccentrics being put in backwards....... :?: :?: This is not true as they share the same chamfer on both sides and a oil groove 180 degrees from the keyway. I agree with Randy's statement on addressing thew gear wear. Although I have successfully ran a camshaft without a oil slot tunning around it I do believe that the higher the flow the easier it will be on the gears. Oil type also falls into place. If you run a 5w30 the shear of the oil may actually cause the wear as well.

[jeepsr4ever]

little tip if your having this happen. Look at the end of the cam on the back side of the cam (nearest to the firwall) does the camshaft have relief holes for pressure? Should have holes to relieve the pressure between the end of cam and cam plug (freeze plug) new summit cams must be checked for these holes.

Hey AL you reading this?


Pics to come soon

[FSJnovice]

thanks for the info everyone.

[73hornut]

I was building my 401 short block, and when I was installing the cloyes timing cam gear, I noticed the the notch in the back that lines up with the hole in the cam, didn't line up. It was off about 1/8 in. Took my die grinder and widend the notch. Just something everyone should check.

[Al Johnson]

Whelp, I "think" I fixed my eating distributor gears problem. I finally broke down and bought a nickel plated timing cover from MC. Nice part for sure. I had to hone the tips of my oil pump gears to eliminate a slight scraping on the walls of the gear cavity in the pump. I have about 18lb pressure hot idle, and 60lb at around 1500 RPM and up.

I used 1" long spring pins for alignment pins. The factory ones are about 5/8" long, and I just didn't feel these were doing the job. Also, I had been cheaping out and reusing an old worn out pair, NOT a good idea. My timing cover, the old one, had worn alignment pin holes as well.

So with a fresh timing cover, and most importantly new long alignment pins, it's been going good for about 3 weeks now. I am afraid that I spent a lot of money on parts I didn't need before getting the combo right.

Hope this info helps someone else with their distributor gears!

Al

[Elliott]

Good deal Al, that certainly was a very long haul to sort that one out. Thanks for tip on the longer pins too!

[Gremlin4ever]

A misconception that I have experienced even at the parts house is the difference between "cam" & "timing" gears alone. I needed a new cam gear, but all the parts counter kept bringing out was the timing gear.

TIP: Cam gears drive the distributor gear while timing gears are run by the timing chain.

Please be careful when your on this topic were ever it may be, parts house or over dinner, or everyone will not be on the same page. And that will lead to an enrollment in your local Anger Management Program.

Just my 2¢

[BRAD ARTHUR]

i newly rebuilt a 304 amc. 500 miles after rebuild i had a cam gear get chewed up. and another 250 miles another cam gear wasted. which is where i am now???

at the time of the rebuild i used a summit 8600 cam, cloyes timing set, a bulltear nickel timing cover and oil filt. adapter, and Z&M JEEPS amc hei. ran great, liked the hei distributor. 500 miles later ate the cam gear that drives the distributor. tore it down and found 1- summit cam had 1 oil relief hole in end of cam, 2-cloyes timing set had flashing blocking the oil gulley to the dist. gear, and 3- the machinist that assymbled my motor used the old cam gear and i used the hei with a new gear on it. after talking with MC @bulltear i found everything could be wrong- the 1 hole, the flashing and mismatched gears.

so i ordered an edelbrock cam, removed the flashing , a new matched gear set from bulltear. the edelbrock cam had 1 hole also? installed it anyway, after talking with MC. got it running again!
after 100 miles i reset the timing pulled distributor and checked the gear. noticed the hei had a bit more end play than i remeberd. ran excellent for the next 150 miles.

then dead again, pulled dist. to find cam gear wasted again. took timing cover off again, checked the end play on the dist. and it has .125 (1/8in.) movement up &down. i know this was more than i started with. MC says it should be around .016 play.
my question is what could have caused this play in the dist., and what can be done to fix it. when i first installed it there was a gap between the dist. housing and the timing cover, and as per the instructions-use a gasket or a shim. wasn't a big gap and the gasket seemed to take care of it. could it have been tighted up to much and pushed the shaft up causing the excessive end play?
now with the timing cover off and oil pump installed , put the distributor in and seems to need a shim between the housing so it won't bottom out on the oil pump shaft. the shaft on the hei is 2 mm longer, from mounting surface of housing to end of shaft, than my old distributor. if the distributor had .016 end play looks like the gear and the shaft would be aligned properly.
any suggestions or thoughts, could the end play come from the first gear trashing, when the distributor skipped a tooth and died? then not checking the end play on distributor and running it cause a 2nd cam gear to go out??????

[73hornut]

Brad, If you look a few posts up, you will see what I wrote about the cloyes timing set. The notch in the back of the cam sproket is very narrow and dosen't line up with the oil hole in the front of the cam.
Jim

[BRAD ARTHUR]

hay thanks for the info , hopefully i fixed trhe oilingprob the first time but i will double check that one ths time. i beleive that after the first time the dist. jumped a tooth when the cam gear went, it pushed the dist shaft/gear up causing excessive endplay on the dist. not catching it i ran it 250 miles and another gear got chewed. the dist. gear rode up on the edge of the cam gear causing premature wear. the cam gear is wore right in the middle of the teeth, as if the teeth were split in two. and there apears to be no cam walk because it is wore in the center of cam gear. front of cam gear is high & rear of cam gear is high wore in middle.

[BRAD ARTHUR]

http://www.partsamerica.com/SelectParts.asp?SourceArea=SHOP&PartType=166&PTSet=A&Description=Engine+Parts+%26+Mounts&SourcePage=PartTypes&SearchFor=Timing+Set

ha sanyone heard of different size timing sets for amc v8 this site shows a 7/8" and a 5/8" . whats up with that. should it be a concern, for camgear wear? never heard anyone else talking about different width chain and gears.

[fuzz401]

1 could be a single roller chain the other could be a double roller chain

for a little more money this is a good timming chain set
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&tc=photo&item=7919729794&category=33625

[BRAD ARTHUR]

it happened again for a 3 rd time. after 20 miles i pulled the distributor to check the wear , and the cam gera again?????

1)this time i changed timing set from cloyes to edelbrock and it is much much better quality and heaveir timing set.
2)z&m jeep treated me excellent on service after the sale ...snet my distributor to them because i thought uit had too much end play1/8" , they reshimed it checked it all out and gave me a new cap and rotor, then shipped it back to me. excellent service and product from a small company, i would recomend them over the bigger more expensive hei's out there.
3) after reinstallation this time i left the fuel pump off ,so when i primed the oil system i could see if their was oil coming out front cam gear. there was! so this isn't an oiling problem
4)i am still using bulltears nickle timing cover
5) the 2nd cam shaft edelbrock performer/ first was summit 8600
6) a matched distr. drive gear set from bulltear both times

i really don't think i have cam walk, iam getting oil to the gears .......my guess............the dist. needed a shim between the housings, the flat , bottom of the dist shaft was not bottoming out on the oil pump gears.........although when my cam gear gets chewed it seems to be the same everytime::::: the top half of each tooth gets the wear:::each time. where the distr. shaft becomes round from flat could be bottoming out not allowing the gears to mesh deep enough.
2nd geuss the oil pump gears are not the ones that came with the timing cover..... could possibly be to long of a shaft not allowing the distr. gears the mesh properly .
thats all i got .........................i have about had it with this problem there has to be a logical explanation to it. any help or measurements on timing cover ,oil pump shaft ,or distr. gear/shaft depth would be great? orv any other suggestions
please help me
thanks brad

[jeepsr4ever]

Your nickel cover must have hand fitted gears. My guess is that the machinist who assembled your motor forced the gears in the case. Take the pump off I will send you a new gasket. Make sure the gears spin freely without the distributor in.

[BRAD ARTHUR]

he said the new oilb pump gears were spining free , and the ones that were originally in it would not? i don't know i didn't heck them. i will now . is there different thinkness gaskets for the oil pump . i thought i read that some oil pump shafts were 1mm longer than others? if the gears weren't seated fully would they wear that quick? same oilgears have been in there since 1 st start.
i think i am finding all possibilities to this problem that could ever happen, what do you think> also about dist. bronze gear or have any measurements?

[BRAD ARTHUR]

yesterday i was checking everything out thouroghly. the last gear that got wore out was only after 20 miles. cam gear again, i changed timing chain set to an edelbrock set, and used z&m's reshimmed distributor with a matched set of distributor drive gears. all that was different. i found yesterday that the new edelbrock timing set had a # cast on the cam gear(# 1420) my fuel pump ecentric was touching on the 0 the way the key ways line up wasn't allowing the ecentric to lay flat on the timing-cam gear. 0 was raised about .030" , this could of threw the alignment off on the dist. drive cam gear. and allow some oil to escape before it got to the dist. gear. since the gear only lasted 20 miles i feel that was my problem, and that was a 1st time for that timing set.
i pulled the oil pump gear and everything there was fine can be spun by hand easily with filt. adapter installed. the pump drive shaft wasn't beviled at the end of the flat drive, so i took some material off ,just in case the distributor shaft was bottoming out, at the top of the flat .
the cam can be pryed out of the face of the block .090" (with use of a pry bar). it only has .050"-.060" before the bolt on the cam hits the cover. there are no marks on the cover. very little movement, is this normal? a cam botton could only be .020"-.040". no other signs of cam walk.
i installed new longer rollpins for aligning the timing cover, i am using a factory cam gear and a mallory brass dist . drive gear-pre soaked in lucas. i will also prime the oil pump and check oil flow out of the cam -dist drive gear-via the fuel pump hole.
any other suggestions or comment are welcome. again the 1st gear lasted---- 500 miles---- no oil through the timing-cam gear& mismatched drive gears,---2nd 250miles--------- ditributor end play was 1/8" the step shim (that came with the bulltear gears set)was installed upside down, ---3rd------- 20 miles 0 cast in the edel. timing-cam gear was hitting the fuel pump ecentric not allowing them to sit flush.
boy these amc parts have a lot of quality issues, just fine details. hopefully this takes care of all problems i would like to drive it someday.
thanks for everyones help, and give me your comments . please
thanks brad

[Dusty]

Dont know if this helps you much but i just went to pickup my distributor from the machine shop..... Edlebrock FI kits come with undrilled. they put the gear on with the gear facing down and the polished end up. #-o correct me if im wrong here but it gear up polished und down. Oh well flip the gear over put a pin in the wrong hole redrill. this time they will read the instructions a little closer instead of assuming.

But that would create a little bit of stress too on the gears.



So did ya get her straightened out Brad?

[BRAD ARTHUR]

yea i think, have about 300 miles on her and shes still going. pulled the dist out at about 150 and gears still looked new! finally!!
thanks to mc, i ended sending everything besides the block to him, he mocked up all parts and found the distributor was .012" to long. if you've followed my story that wasn't my only problem. i think all parts that could be wrong, were.
my advice to anyone having this problem check all parts thourghly. i changed most parts at one time when i rebuilt. didn't know all that i know now. when you assemble check the parts with mc list of possible causes. the quality of alot of these after market parts, suck . i think they design&build of one engines parts and don't alow for much differences, and there quality control isn't much better.
check your new parts vs. old parts, ask for help on this site.(everyones been very helpful to my problem), make sure you get oil to dstr. gear, all parts look good.
thanks mc and everyone else that has sent me replies i hopfully got this problem whipped!!!!!!!!!
finally back to jeepin!!!!!!

[jeepsr4ever]

Thats great now you can finally enjoy that engine...BTW it was .120 not .012 :mrgreen:

[bobhalverson]

one thing no one has addressed is if you suck some air up in your oiling system, where do you think it goes? it's not going to flow down to the rods & mains, air floats!! it will go up & forward in the engine- so it ends up at the front cross galley & will end up in the front cam journal- until the air passes through, you have no oil to the cam & dist gear- we always need to prime the oil system on a new engine start up to give full oil to the gears, and if you pick up any air in off-roading or on a rough circle track, we need to consider raising the oil level in the pan or devising a way to vent air from the front cross galley, such as a .040" hole in the cross galley plug - the only time i had a 360 eat a gear was when we had problems on a rough stock car track & it sucked air on the corners. maybe the extra oil line to the front cover trick would be a good place to vent the air out quickly- after we added another qt to the pan, the oil pressure stayed up & everything lasted well.

[buttabean]

Help, this is an expensive build with edelbrock pro flo and much more. New everything, except timing cover. It seems to be in great shape, no visible wear. I think the oil pump set might be the problem. It seems to be tight, it feels funny like the gears are pulsating when turned by hand. They can be turned by hand though, so I dont know if that is considered loose enough or not. The oil pump gears seem to be slightly above the deck of the oil pump surface, so I will get some plastigage tomorrow and measure the tolerances.

I also ran 5w30 not knowing any of these issues before hand. How likely is that the cause? I never heard of oil causing extreme wear of this nature?
It is brand new motor, and I had great oil pressure after priming. I am sure it is a tight motor and I was worried about running too thick an oil and blowing gasket and seals.

MC what is your reccomendation from here?

[jeepsr4ever]

Emailed you

[buttabean]

OK, frustration setting.

I munched a second gear now. Its been 60 miles or so and I pulled distributor to check it out. I can see the wear straight down the center of the cam gear. It not broke yet, buts it's a few miles away. Looking at the pictures of your gear, it seemed to have flatter surfaces where the gears mate. My cam gear(both) from Mopar seemed to have tapered mating surfaces. I ran stock oil spring, and 10w30. max 2500 rpm. still breaking engine in. Oil was 60-65 psi hot, 70 psi cold at 2000 rpm.

How do I get matched gears from MC. ?

[jeepsr4ever]

The matched gear sets are around 3 weeks out. If your oil pump is tight you will need to take a file and take the edge off your gears to allow it to turn easier.

[buttabean]

I need them ASAP. Can I order them anywhere else? Or are they being made custom somewhere? I made sure there was not a rough or sharp edge anywhere on the oil gear. They spin super cleanly and not an edge catches like they did out of the box.

[AMC]

Have there been any problems with Comp cams?
I have an MST pro billet destributer.
Bad cores, non-matching oiling holes, Gears?

[buttabean]

MC, did you get any gear sets in yet? I also saw some posts about development of cam buttons last year.

I would like a button as well just to be on the safe side, although I don't beleive I have that issue, I am trying to eliminate as many possibilities as I can.

Please get back to me, I have had my daily driver in the garage now 4 months.

again, I need a cam/dizzy set and cam button.

[jeepsr4ever]

The whole united states is short on gears........ :oops:

[BRAD ARTHUR]

i think i used too many of those gears when i had my problem. or problems plural, very frustrating problem.

[jeepsr4ever]

Hey Brad!! Jeep still running good for you?

[BRAD ARTHUR]

yea no problems almost 3000 miles on it. still want more power and trying to dial in the timing and carb. i really need that edel. fuel inj., headers, or underdrive pulley.

[bluesman2a]

thanks to mc, i ended sending everything besides the block to him, he mocked up all parts and found the distributor was .012" to long.


Thats great now you can finally enjoy that engine...BTW it was .120 not .012 :mrgreen:

Wanted to bring this BTT, I'm having similar issues, still on round 1... What was done to resolve the ZMJeeps/Dizzy issue mentioned here?

Other stuff I'd like to throw out here for some help:
1) Low mileage rebuild engine. Old cam gear with new dizzy gear 100 miles in it eats the cam gear.

2) Thus far I have taken the following steps:
A) replacing cam/dizzy with matched set from Bulltear.
B) Timing cover/oil pump look good, no scratches/gouges, but am replacing with Oil-pump reloaction kit and no discernable extra play here.
C) Replacing cam with Edelbrock Performer kit (matches intake and I'm not an engine guy)
D) Replacing timing set with Edelbrock double roller set

What else can I do to make sure this goes back together properly for longevity? Any assistance would be appreciated from this noob!

[buttabean]

I have put 500 miles on minenow after previously munching 2 cam gears in 40 miles. The culprit was a mismatch. I used a dist gear purchased from jeep/mopar and it ate the cam gear twice. I changed oil today and pulled the dist to check wear. Cam gear and dist gear have no marks and look like new from the bag.

Note----just as a precaution I put in the Nick Alfano anti-walk kit just to eliminate cam-walk as the culprit. I had edelbrock timing, but not anymore. Also have edelbrock cam and external timing chain oiler redirected to oil the dist/cam gear as well as splash extra oil to the timing set.

After comparing the 4 different dist gears I have laying around, I used the gear from my previous motor. Dist was less than a year old and looked the same as the other gears I used in the past. The mopar dist gear is distinctly different, having tapered edges on the top the teath that I suspect are cuting into the middle of the cam gear on its way through its motion across the cam tooth. Now that I look this closely I see why it is not a matched gear.
I can post a pic in comparison if anyone wants to see the what I suspect as the "ISSUE" with this dist gear.

There are many possible causes but I found mine.

[bluesman2a]

I had edelbrock timing, but not anymore. Also have edelbrock cam and external timing chain oiler redirected to oil the dist/cam gear as well as splash extra oil to the timing set.

OK, dumb question, are there known issues (oiling, etc) with the Edelbrock timing gear I should be on the lookout for?

[jeepsr4ever]

I had edelbrock timing, but not anymore. Also have edelbrock cam and external timing chain oiler redirected to oil the dist/cam gear as well as splash extra oil to the timing set.

OK, dumb question, are there known issues (oiling, etc) with the Edelbrock timing gear I should be on the lookout for?

Yes you can look at the oiling groove in the inside hole where it slips on the camshaft....see if its distrupted by casting flash and then grind it out accordingly

[mechanical man]

jeeps4ever,
I am having dist gear munching problems. I see someone mentioned matched sets from you. I cannot find them on your site. Do you sell them?

chuck
87 GW
96 XJ

[jeepsr4ever]

go to the products area in the forum and look in the AMC V8 area...from there you can buy them

[Mudrat]

nope the rules change dramatically for the sixes

[93mustang]

Where do you get the anti-walk kit from for an AMC 304? Does Bulltear sell these too? And are the matched gear sets for the 304? Did not see these when I clicked on the products section.
Thanks!

[buttabean]

I am not part of Bulltear FYI----but here's my scoop----

Anti-cam walk kits are available on ebay from maddog racing. I do not know if Bulltear caries them although they recommended them to me as well.I have bought many parts from them and they are reputable. They are designed by nick Alfano and well worth the peace of mind.

Almost all parts on AMC 304-360-401 are the same. The exceptions being heads and valves(304 uses smaller heads.) Also, crank/rods/pistons etc. will generate the different displacements(not interchangeable for stock applications) or flywheels(for balancing and weight.)

Cams/lifters/oilpumps/water pumps/timing covers/intake manifolds/exhaust manifolds/rockers/pushrods are all the same.

Hope this helps

FYI. my 360 made 600 miles so far in break-in and snapped my driveline on a sharp shift in to second. Pretzeld the tube, u-joints held up....torqee motor!!

[jeepsr4ever]

We do reccommend teh anti walk kit sold by Nick and Maddog but the kit was a design not pioneered by Nick Alfano from what I understrand someone showed Nick how to do it and he marketed it.

[93mustang]

Okay, but on the gears, are they in stock or on backorder? Could you tell me why you don't reccommend piping an external oil line in to spray lube on the gears? I have seen several places that suggest it and just wonder.

[jeepsr4ever]

Gears are in stock. We wont ever recommend the external line unless you are running a roller camshaft. It isnt required unless your running a roller camshaft. That is what it was designed for. The hydralic cams have oiling provisions.

[93mustang]

Okay, thanks.

[mtjeeper]

Gotta bring tis one BTT.
360 with a rebuild last January, MSD probillet dist, cam and timing gears unknown. The reason I had the rebuild done was because I was chewing the dist gear about 4 times, replaced the cover 3 times (first 2 from BJ's and 3rd from MC)and said enough was enough.

So here it is about a year later, and it happens again only this time it only chewed half of the gears, one side looks perfect but the opposite side is destroyed. http://community.webshots.com/album/510056966gFOAiM here are some picts.

anybody have any idea why it would only chew half. the only thing I can think of is if the dist isn't true but I would find it hard to believe a MSD would crap out in les than a year?

Thanks, Matt

[buttabean]

hmm....I have heard that most of these problems are the dist gear chewing the cam gear. How does the cam gear look?

Send me a pic of the tooth profile...I know that the mopar dist gears are not correct but I cant tell from the remains of yours.....send a pic of the good side showing the edge of the tooth from top or bottom view of the gear, instead of the side view.

Buttabean

[mtjeeper]

well, i would but the shop came and got the waggy already. I'm just trying to educate myself and make sure they get it fixed correctly.

I had a neighbor say it could be cam bearings making the cam wobble?

Thanks,
Matt

[pyagid]

What cam do you have? I know some of the summit cams ended up having some slag covering the oil hole at the end, causing the cam to walk But that should cause the gears to eat them selves much faster than a year

-Paul

[mtjeeper]

hey paul, sorry it took a while to get to ya. I thought my builder put in a Comp but it turns out to be an Engine Performance Warehouse cam(?) i had never heard of 'em. if they end up rebuilding it i'm gonna make sure it's a better name brand. I've got all the specs of the cam, just not infront of me right now.

Matt

[stroked401]

This is all very interesting information, where does a guy get a matched set of gears? Both cam and distributer.

[Mudrat]

This is all very interesting information, where does a guy get a matched set of gears? Both cam and distributer.
The Bulltear E-store ... (http://www.bulltear.com/catalog/advanced_search_result.php?keywords=cam+gear) < - - - clicky

[fuzz401]

< - - - clicky


cool :t: :-|

[tarior]

I've had quite a few AMC v-8's and I have only had one with severely worn dizzy gears, those were in the 360 that came out of my '73 Jav/AMX. It was so sludged up that oil would run down the valve guides faster than it go back down the drain holes. I had shove a screwdriver through them to get them unplugged. Funny, it actually ran pretty good, didn't smoke so bad after I unplugged the drains :mrgreen:

[stroked401]

Gears are in stock. We wont ever recommend the external line unless you are running a roller camshaft. It isnt required unless your running a roller camshaft. That is what it was designed for. The hydralic cams have oiling provisions.

What is the difference between a roller and solid cam making the external line required on the roller cam?

[jeepsr4ever]

Solid lifter still spin and retain the camshaft and therefor there is no need for cam walk provisions. Most cam walk kits cut off oil to the cam gear as well as most (older) gear driven timing system.

[stroked401]

OK, I know exactly what you are talking about now.

[stroked401]

What about the most recent Milodon gear drives, same story with them? Not sure if they have ever revamped them or not, just wondering?

[jeepsr4ever]

No sure its been 3 years since I tinkered on that end

[stroked401]

Is there any other options other than Milodon for gear drives?

[Mudrat]

Is there any other options other than Milodon for gear drives?
Try Mad Dog Racing at Fast Engine Parts (http://www.fastengineparts.com/) - that's where I got mine after recommendations ... double roller set ...

Pat

[tarior]

That Rollmaster billet timing set looks pretty darn good! :lo1l:

[Mudrat]

Looks a whole lot better than what I took out!!! :lo1l:

[jeepsr4ever]

Gear drive Pat not roller chain drive :wink:

[tarior]

Looks a whole lot better than what I took out!!! :lo1l:

Yeah, I don't even need one, but I'm tempted to buy one anyway , just 'cause their so purty. :mrgreen:

[Mudrat]

Gear drive Pat not roller chain drive :wink:
Party pooper 8)

[oldscout401]

Hi guys, I'm new here. This is the best AMC site I have ever seen. I have a 76 CJ5 with a stock 75 401 in it. Just bought one of those HEI dist. and it came with its own gear on the dist. shaft. After reading this thread I thought it might be a good thing to replace the new gear with the original. Any input on this?

[tarior]

If your original is good, you should use it, IMHO.

[Mudrat]

Just make sure you have the same tooth count on drive and dizzy gears. I've read there have been 2 different sets out there. I haven't gone through the entire "AMC Oiling" (http://www.bulltear.com/forums/viewforum.php?f=25) thread, but I'm sure it's there...
As well as other threads like THIS (http://www.bulltear.com/forums/viewtopic.php?t=4640&highlight=oiling+gears)

[Al Johnson]

Up in the woods on vacation last week, with my granddaughter yet, and the cam gear munched. Been a long time, thought I had it licked. Got everything home now, but it was a long weekend going back and forth to pick up the Heep and the travel trailer. So it's broke agin, what now? Another set of gears, and a lot of hoping? Or a SBC? Ya, I know, blasphemy, but I gotta be able to depend on this thing more than I feel I can right now.

[AMX69PHATTY]

Question. There is a dimple or indicator in the end face of a few sets of AMC Oil Pump Gears that I have. Is the purpose of these dimples that they should be aligned with one another when installing the Gears into the cavity in the Timing Cover since this is were they have been matched ?

Question. I measured the shaft length from the top face of the gear, not including the gear itself, to the distributor drive end on a couple Oil Pump Gears. One is 4.823", the other 4.812". Are these within what is know to be the proper dimension. Might one know the "blue print" dimemsion and the tolerance for this measurement ?

Reading all this good information can drive one mad if they're not careful.
Ignorance is Bliss ......... :mrgreen:

[jeepsr4ever]

The dimples are where the hot metal gets injected and doesnt matter for alignment. The shafts arent critical unless they are too short or too long. You will find they vary up to .05"

[1980_Cj7]

In the front cam bearing, is there supposed to be a groove the whole way around the bearing, the cam, or both?

How many oil relief holes in the back cam journal? The stock cam has two. Didn't get to check the new cam yet.

[AMX69PHATTY]

Front Cam Bearing and/or Journal, as I understand it, the groove can be in one or the other or both, just as long as it's there.

Rear Cam Journal Relief holes, either one or two, just as long as they're there and go all the way through.

Also may want to check that each of the Cam Bearings in the Block are installed such that the hole through the side of'em lines up properly with the Oil Feed Hole in the Block itself.

Bulltear I believe has Cam Bearings available with reduced Oil Hole size to limit oil delivery to the Cam Journals and improve Oil flow to the Crank Mains and Rods.

[jeepsr4ever]

Yes front camshaft bearing needs a groove around it so the camshaft and distributor gears are always fed oil. I do believe all current sets have this groove.

[Gambler]

Very helpful thread!

Part of the pile of parts I got for rebuilding my 75 401 was a Cloyes double roller set. (from MadDog). I had paid for the upgraded option on their 270 Cam kit, and although he said on the phone the upgrade was the SA Gears, I got a cloyes kit. It's certainly not as pretty as the SA Gears, but it's a double roller, so whatever. Anyways, I saw in this thread about the oiling groove in on the cam gear (which I assume is the larger of the 2 gears in the set, regardless thats the one I'm talking about). The oiling groove is IMO sloppy, exactly in the middle there's a little ridge. Is this the flashing which needs to be removed? The groove is plenty wide front and back, it's just in the middle where the obstruction is.

thanks! :t:

[1tuffcj]

great thread and great site. i'm just finishing up a ground up build on my 79 cj5 with a 401/727t/f, i put a comp cam and a pro form dizzy, new timeing cover, new oil pump and gear's. beside the leaky head gaskets, i had 25 psi at idle cold and hot when i rev it it dos'nt seen to go up in pressure, is this correct does it need to be under load to make the pressure rise. i don't know if the gear's are gonna break or not, i have to test drive it, trying to fix the head gasket problem. post in engine section. thanks mikey

[northplainsdrifter]

Great info in this site.

I put an HEI in an older 360 and shredded my cam gear. With all this info I don't need to ask questions, I'm getting a matched gear set and should be hitting the trails fast! :lo1l:

[Jeepnofear]

I bought a new short block and it was my daily driving for about a year at about 70 miles a day. It sat for a year and half but I started it once or twice a month while I was restoring the truck. When I finished restoring it I started driving it alot again and everything seemed fine then the cam gear stripped and the fuel pump went out at the same time. Oil pressure was fine.

Can miss matched gears last that long?

[rollbar]

So with all that, what oil filter do U recomend for a '74 360. I don't know what's in this motor but I did fire it up a while back & it sounded like it had a little work.

Some old pic at that stage of the game.
http://www.street2mud.com/albums/M170Start/100_0189.jpg

http://www.street2mud.com/albums/M170Start/100_0185.sized.jpg

Here is one w/just the body sitting on it cause I had to move it to my new residence. I have to use a short oil filter cause it is very close to the bracket before the m-mount. U can see the bracket in the first pic.
http://www.street2mud.com/albums/M170Start/100_0750.sized.jpg[/url]

[Mudrat]

So are you ALL voting when you see the link??

VOTE (http://top4x4sites.com/cgi-bin/arp/rankem.cgi?id=MCfrom)

We need to get everybody to click just a once a day!!

[rollbar]

I voted :t:

[Mudrat]

rollbar, just loked at your pics again (cause I think it's a cool green :wink: ) but I just noticed your alternator belt doesn't loop the crank pully. Any reason???

[rollbar]

Just keeping it shorter. U think it would be better to run it by the crank & if so, why. If I do run it there I would need a idler pully, correct.

P.S. I have the other bracket for the front of the PS unit.

[Mudrat]

Well, being shorter you wouldn't get the whipping motion I see in mine, but your making the water pump into a driver instead of an idler. Just hadn't seen it like that before. And if you lose the PS belt, you've also lost the water pump and the alternator, instead of just the PS - no redundancy. To replace it (trail spare?) you have to pull the PS belt off anyway, so I guess it's 50/50. Don't think it would hurt anything if you can pull off the trail and fix it before the battery died.

An Idler would be a nice touch to keep the belt from vibrating so much :t: That's why I'm hoping for an afordable serpentine setup :wink: With the idler holding tension, swapping them out would be pretty nice and only need to carry 1 belt as a spare :?

[rollbar]

Well I C your point, maybe I should change it and add a idler pully where the old bracket is just under it. I would really like to move the PS unit down into the hole so it's not 10 miles up in the air. I might get it going and then check into it but then again, it's easier to do it now B-4 the front end is on.

[Mudrat]

It would be easier to access, that's for sure. Maybe MC can make up a lower mount, I'd like to get mine outta the way of the dizzy as well. And I still think it looks cool in OD :t:

How the rest of the conversion coming?

[rollbar]

Click on my link in my sig line. The underside of the tub is done and after I get the tranny lines in I will install the tub then paint it and rock-n-roll.

If MC could make one it would be great and to be ABLE to have ROOM to get to the fuel pump.

Maybe I can be a proto type :)

I still have to buy the oil block off plate from him when I get a chance.

[wildly]

How can I view, cast timming cam gear, old style roll master cam gear and new style roll master with bearing cam gear. Also any other pictures that will help me with my repair.
Thank you very much for your help.
Wildly

[jeepman1]

Here is a list of things that can cause distributor and cam gear wear.



1. Oiling holes throught the large timing gear, the groove for the oiling hole must be at 2:00 from the keyway, also all passages must be clear.

2. Cam bearing at the front of the block must have a groove in it, this sends oil through the cam at all orientation and rotation of the camshaft.

3. The cam must have a 90 degree oiling hole setup to feed the timing gear and must be free from casting obstruction.

4. Cam gear must be matched to the distributor gear. Their are 2 types of cam gears out there and at least 3 types of distributor gears, they CANNOT be mismatched, replacing just the cam gear will cause big problems.

5. The timing cover: The oil pump drive gear's shaft that connects to the distributor goes through a hole in the timing cover, this is a precision hole and if tapered can cause distributor gear wear through chatter.

6. Oil pump gears: Using longer than stock or poorly made after market gears can cause chatter, binding or premature wear of the oil pump drive gear's shaft hole. When you install a aftermarket kit that comes with new gears the idler gear pin MUST be longer. The cam and distributor gears are only rated at a certain torqueload. Some of the new gears available as of 4-22-05 are now hardened (both gears) and can withstand greater pressures

7. Oil filter.......Yes oil filters can cause premature dizzy and cam gear wear. If you run the wrong oil (too heavy) or a filter that gets clogged early or a filter that isnt a high flow you open up your oil filter bypass and not only send dirty oil through your motor, you also exerpt a high amount of pressure on the oil pump and that alone can cause gear wear, this happens mostly on start up. In late 87 chrysler got rid of the oil filter bypass on the oil filter adaptor, after market oil filter adaptors also have this cast in. Beware that if you use a high pressure oil pump spring without a oil filter bypass you run the risk of ballooning your filter.

8. Cam walk: Cam walk can be attributed to a cocked or poorly place cam plug (large freeze plug that hold the cam from leaving the rear of the block. Also cam walk can be caused by bad lifters, worn cam bearings, cam bearings installed improperly, or a poorly ground cam and in some cases a new cam that gets flattened on startup

9. Cam walk can also be attributed to lack of relief holes in the back of the cam, you see pressure can increase between the end of cam and cam plug, most of these cam must be checked, we have 3 in here with no relief holes...............dang summit

10. The retainer washer for the front of the cam that holds the distributor gear must also provide a positive seal for proper oiling. Off the shelf washers can sometimes have nicks or be convex or concave which to factory torque specs can lead to a loss of oil in front of the camshaft.

11. The installation of the timing cover without locator pins or worn location holes will cause a mis-orientation of the thrust on the distributor gear and eventually may result in a broken or heavily worn set.

12. Early Crown timing covers that were not checked for proper dimensional tolerance can attribute to up to 100% of the fast gear wear. Even today vendors should check for proper alingment.


I have seen a AMC V8 go 210,000mls without any cam walk and very little gear wear. I have also seen a AMC V8 go 2 miles and eat the gears. The factory engineers knew all this and they put these motors together accordingly. Building a AMC V8 can be a expensive build and its a dirty dirty shame to have something like a cam or distributor gear go out, this can cause Major scoring on the oil pump cavity and also can cause the oil filter bypass to open and voila, roached bearings. Hope these hints help anyone out who is building a AMCV8.

-MC
Good info is hard to come by..