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diddycj5
01-12-2004, 02:45 PM
I am looking for some decent used dana18 gears since I am thinking about doing the dana20 2.46:1 upgrade. (I *think* I have the right bronco dana20 rear slider gear already). Yes, a 3.15 teralow is lower, but also $850. This should be half the improvent in ratio for less than a quater the cost.

Does anybody have either loose gears lying around or an entire dana18? I would prefer a later model18 with the 1-1/4" intermediate shaft since these had better wear.

The gears I need should have the spicer p/n stamped into them:
18 8 24 - output gear/29 helical teeth/ 12 spline
18 5 9 - intermediate gear/39 helical teeth 18 straight teeth
18 8 22 - front slider gear/33 straight teeth/12 spline.

Also if anyone has and early bronco dana20 T-style gears/t-cases lying around please let me know since I have a friend who wants to also do this swap.

78304CJ-7
01-18-2004, 10:45 AM
LOL I am doing this exact same thing this week, I used most the gears out of the Bronco D20 case, it had all the ones I need but two. The only gears you should need from the D18 are 18 8 23 and 18 8 22 , one is the lower slider gear and the other is the input (bull gear) you should of got 18 5 9 from the EB D20 case.

Let me know if you need any help with this. I will be assembling it tomorrow when my gasket set comes in.

What is the number on your rear slider gear, it need to be 33 tooth (the original D20 is 31 tooth)



-RJ

jeepsr4ever
01-18-2004, 11:07 AM
I may have 2 18 cases tomorrow i can split for you guys, otherwise in feb i will be selling these gears new

78304CJ-7
01-18-2004, 03:37 PM
I thought it was Mid jan MC..... 8)

LOL no prob I found I guy who had the two I needed. Let me know I am alway up for some more gears, but they have to be from the later D18, found behind the T-90 mostly, they will have the 1 1/4 inch intermediate shaft. That is the only on you can use for the conversion parts, at least if diddy doesn't have 18 5 9 from the EB D20 case he will need to get it from the later D18.

Let me know if you have the correct D18 I am up for some more gears.

But then I gotta get another EB2 D20 case.

I don't even think my T-18/D20 combo will ever see my jeep anyway.

I have this feeling it will be getting a NV4500 this spring. I think I have two HPD60 being made for the CJ 8)


-RJ

diddycj5
01-20-2004, 10:38 AM
LOL I am doing this exact same thing this week, I used most the gears out of the Bronco D20 case, it had all the ones I need but two. The only gears you should need from the D18 are 18 8 23 and 18 8 22 , one is the lower slider gear and the other is the input (bull gear) you should of got 18 5 9 from the EB D20 case.

Let me know if you need any help with this. I will be assembling it tomorrow when my gasket set comes in.

What is the number on your rear slider gear, it need to be 33 tooth (the original D20 is 31 tooth)

-RJ

RJ - I think that I have all of the gears now. I bought the 18 8 23 off of ebay a few weeks ago. I found a local jeep rebuilder place that had the 18 5 9, 18 8 24 & 18 8 22. However, just like you I am looking for more sets of gears since I have friends who want to do the same conversion. (My dad's '63 CJ5 also has a D18 that needs some serious loving soon so extra gears would always come in handy). I might not be tearing my T-case apart for a couple months as I need to finish my other jeep projects before I start disassembling my jeep that much more. However, I would be very interested in seeing how your gear swap goes. Take lots of pictures. :sa:

The EB Dana20 rear slider gear I have has the spicer p/n 18 8 37 stamped into it. I know that all of the online info says that this gear should be 18 8 58, but I couldn't find that one anywhere and haven't found a local EB D20 T-style case around for reasonable price to buy. I bought the 18 8 37 from a bronco junkyard who had a bunch of loose gears lying around. So I dont 100% if the 18 8 37 came out of the T-style or J-style EB D20.

The 18 8 37 gear is 33 tooth - 15 spline - definitely a rear slider gear. It is visually the same diameter as the D18 33 tooth front slider gear. The shift fork groove looks identical to the jeep D20 rear slider. Also, the 15 splines fit the 15 spline bull gear out of both jeep D20 & D18's. (I have an extra set of Jeep D20 gears laying around that I also compared to). The only thing I am not 100% sure of is if my 18 8 37 has the correct gear pitch/angle. Novak's webpages shows that the D18 gears had tooth angle of 20degs and D20 gears were 17.5deg teeth. How do I measure tooth angle/pitch? I have dial calipers, a small micrometer and a dial indicator with the magnetic base.

MC - RJ was correct that the gears we are looking for should come out of the later D18 with the 1-1/4" intermediate shaft. I have a friend with a scout D20 who wants to do the same thing. Let me know if you have the right D18 gears and how much you want for them.

78304CJ-7
01-20-2004, 12:13 PM
Diddy, Well I should be getting my kit for the D20 today so I will begine reasembly today as well.

I am pretty sure that my EB20 case was the "T" style, I am however not sure how to tell. I got it for free with a bunch of parts not even knowing what it was.

Here are the gears I got from my EB20 case:

18 8 24
18 5 9
18 8 37 (SAME AS 18 8 58)

I needed and pickud up from a guy online:

18 8 23
18 8 22

The 18 8 37 is the same dam gear as the 18 8 58 I have no idea why not one online writeup about this swap talks about the 18 8 37 but I talked to a few people that have done it with the 18 8 37 and it worked fine.

So it looks like I got a few more gears out of my EB20 then you did. We should compare as the tag is still on mine. It would be intresting to see what the difference is.

Novaks page when talkig about the degree pitch of the gears is not refering to the slider gears, they are refering the helicut gear on the input gear (bull gear) intermediate gear and the high range 4wd gear. You should be all set with the 18 8 37 though.

Let me know if you have any other questions.

-RJ

diddycj5
01-20-2004, 12:35 PM
RJ - make sure to take lots of pics & post a writeup on bulltear. Let me know how much grinding on the case you have to do to get everything to fit.

I acutallly bought my 18 8 37 EB D20 gear seperate for $25 and didn't have to find the entire case. I got the D18 gears from a shop that had some already disassembled gears so once again I only bought the gears and didn't have to ship the entire case. I know that you can tell the difference between T-style & J-style EB D20 by looking at the case/shifter. I will look again to see if I can find an exact way to tell. I know that the T-style was in '66-72 broncos and the J-shift was 73+. Also, I think that the later J-style had a higher 4low ratio (more like the jeep D20 2.03:1). If you count all of the gears, you can calculate the 4low ratio - if it is 2.46:1 then it is definitely an earlier T-style case.

I am still not 100% convinced that the 18 8 37 is the same as the 18 8 58. I talked to my jeep expert (he parts out jeeps for a living and has always given 100% correct info before), and we both feel pretty confident that Spicer didn't put different p/n's on gears that were identical - something is different about them. - who knows what it is though...

As for gear pitch off of novak - I think that you are right that they are talking out the angle of the helical gears (duh - why didn't I think of that 111!!! ) .

However, there may still be differences in gear pitch/angle of the straight teeth. The curved/rounded portion of the gear tooth itself can be different between gears. This curve must be matched between all gears so that the teeth roll on each other instead of sliding. If the gear teeth do not mesh correctly and slide instead of roll against each other, wear/friction/noise will be dramatically increased. I was planning on digging out a couple of my Mechanical Engineering books from back when I was in school and doing a bit more research on the subject.

diddycj5
01-20-2004, 12:49 PM
Here are the gears I got from my EB20 case:

18 8 24
18 5 9
18 8 37 (SAME AS 18 8 58)

I needed and pickud up from a guy online:

18 8 23
18 8 22

The 18 8 37 is the same dam gear as the 18 8 58 I have no idea why not one online writeup about this swap talks about the 18 8 37 but I talked to a few people that have done it with the 18 8 37 and it worked fine.

So it looks like I got a few more gears out of my EB20 then you did. We should compare as the tag is still on mine. It would be intresting to see what the difference is.
-RJ

One more stupid thought. Since you got the both the 18 5 9 and the 18 8 37 of the of the same EB D20, they should be compatable. Since the 18 8 24 & 18 5 9 also were used in the D18 they should all work together with no issues. Dana wouldn't have put the 18 5 9 and the 18 8 37 in the same bronco case if they wouldn't play nice together.

I guess I got confused since all of the documentation I saw said that the only gear used out of the EB D20 was the rear slider and they got all of the remaining gears out of a D18. If the 18 5 9 & 18 8 24 also came in bronco D20's then it shouldn't matter. Lots of bad info online. I am getting very cautios before taking any advice from online sources that I dont know if they are truly trustworthy - part of the reason why bulltear is so great - people know their stuff.

78304CJ-7
01-20-2004, 02:11 PM
RJ - make sure to take lots of pics & post a writeup on bulltear. Let me know how much grinding on the case you have to do to get everything to fit.

I acutallly bought my 18 8 37 EB D20 gear seperate for $25 and didn't have to find the entire case. I got the D18 gears from a shop that had some already disassembled gears so once again I only bought the gears and didn't have to ship the entire case. I know that you can tell the difference between T-style & J-style EB D20 by looking at the case/shifter. I will look again to see if I can find an exact way to tell. I know that the T-style was in '66-72 broncos and the J-shift was 73+. Also, I think that the later J-style had a higher 4low ratio (more like the jeep D20 2.03:1). If you count all of the gears, you can calculate the 4low ratio - if it is 2.46:1 then it is definitely an earlier T-style case.

I am still not 100% convinced that the 18 8 37 is the same as the 18 8 58. I talked to my jeep expert (he parts out jeeps for a living and has always given 100% correct info before), and we both feel pretty confident that Spicer didn't put different p/n's on gears that were identical - something is different about them. - who knows what it is though...

As for gear pitch off of novak - I think that you are right that they are talking out the angle of the helical gears (duh - why didn't I think of that 111!!! ) .

However, there may still be differences in gear pitch/angle of the straight teeth. The curved/rounded portion of the gear tooth itself can be different between gears. This curve must be matched between all gears so that the teeth roll on each other instead of sliding. If the gear teeth do not mesh correctly and slide instead of roll against each other, wear/friction/noise will be dramatically increased. I was planning on digging out a couple of my Mechanical Engineering books from back when I was in school and doing a bit more research on the subject.

You make a valid point about the rear slider gear and the part numbers, however I have seen two different part numbers come off the back of T-18 with a D20 attached to them, the one I have is an early 70's version and the adapter to the D20 actually says T-98 on it. I can't remember the part number on the gear but it was different then the T-18 that helped a buddy rebuild that was from a CJ.

Regardless, I don't think it will be a problem.

I can tell you right off the bad the EBD20 that I got was an early one becasue of the way the gears where held on the front output shaft. It used a a little C clip that I had to remove but I first had to seperate the bearing just enough to get the C clip off a real PITA. The Jeep dana 20 was much easyer to remove the bronco one and accoring to:

http://www.tocmp.com/manuals/Bronco/

I used this and it worked to the 'T'

In taking apart the Jeep D20 it talked about early model D20 having to do the same thing. This is from th Novak site:

"On 1962-1965 model 20's that use the thrust washer, tap a large screwdriver between the front bearing cone and the gear to separate these far enough to remove the snap ring from its groove. Do not pry against the gear teeth when separating this bearing as it will almost always chip a tooth. With the snap ring removed and on the forward part of the shaft, the shaft may be withdrawn from the case allowing the gears, thrust washer, and snap ring to be removed from the case. The remaining shift fork can now be turned to gain access to the lock screw, allowing the fork and rod to be removed from the case. It is advisable to take note of the position of the shift forks so they may be properly installed at reassembly. (Item #60 and #61 are found only on 1962 to 1965¬? model 20 transfer cases.) On model 20's that do not use the thrust washer, the shaft can be pulled from the bearing. These units use a spacer between the bearing and the shaft instead of the thrust washer and snap ring."

I think it isn't so much that the info is bad, but alot of it is incomplete I usally take whaever I read and then go check it with 3 other people. You might want to check out a thread I had on the JU board with a fellow that did it. I was just gettin started and figuring out what I needed, I had the same problem the info online SUCKED for this swap.

http://www.jeepsunlimited.com/forums/showthread.php?s=&threadid=472498

It is a good read and I printed out for future refrence.


-RJ

78304CJ-7
01-20-2004, 06:09 PM
I got my case half way assembled today, it looks like Iwill not need grinding for my lower slider gear, however it does look like Iwill need some for my main slider gear. So far so good. I have found that a combination of NovaK and Chiltons rebuild instructions work best.

-RJ

78304CJ-7
01-21-2004, 06:18 PM
Diddy, the case is all put together and I have about 36 pics so far. My endplay on the rear output is a bit high so I have to add a shim or check how my bearing is seated. Front is perfect. I didn't have much grinding to to, only for the main slider gear, I didn't have to do any for the lower slider gear. Spins and shifts like a champ. Bull gear lines up perfect! Now I gotta rebuild my T-18 this weekend :t:


-RJ

diddycj5
02-24-2004, 02:27 PM
Diddy, the case is all put together and I have about 36 pics so far. My endplay on the rear output is a bit high so I have to add a shim or check how my bearing is seated. Front is perfect. I didn't have much grinding to to, only for the main slider gear, I didn't have to do any for the lower slider gear. Spins and shifts like a champ. Bull gear lines up perfect! Now I gotta rebuild my T-18 this weekend :t:

-RJ

RJ, can you post some pics of the D20 re-gear? It looks like your webpage is coming a long but doesn't include any pics of that rebuild. BTW, nice looking rig. I might end up waiting on tearing into my D20 to regear it since the master rebuild kits are $150 and I need a few other upgrades first.

78304CJ-7
02-24-2004, 07:09 PM
I got every imaginable pic of the swap, no time to put on the web site. Let me know what you are looking for and I will send them to you.


The CJ is coming along, getting ready for the 1 ton treatment!

-RJ

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