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

[jeepsr4ever]

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

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.