Dana 20 Transfer Case rebuild T or J..

[motoman]

I wanted to give a shout out and a great big thanks to Steve for his help with the rebuild of my transfer case. I have a 1973 Bronco with a T shift transfer case... or so I thought. Once we open the case up the front output shaft was actually one from a J shift.... bizarre! But the rest of the case was a T shift style. I had ordered a complete rebuild kit from Bronco Graveyard for a T shift and didn't have to use any of the kit because the only bearings I needed was for the J shift.

By the time I got to Steve's house he had completely disassembled my transfer case and cleaned everything. In preparation I had taken my inspection cover to a friend and asked if we could so something cool in aluminum. He taught me how to use a mill and this was the result!!!!

Shelby (son) and I had spent Friday night sanding and polishing the cover. Now at Steve's house we inventoried all the parts. He noted the shift fork was loose we he took them apart. Could be the reason my truck would pop out of hi 2wd.

One of the ears was broke on the cover....

The gears looked pretty good but it was obvious that moisture had gotten into the Tcase at some time. And there was pitting on the gears. We decided to go ahead and keep them for the rebuild.

Steve was just happy to be there!!! ;D

Steve has read where we could modify the shift rails so I could use front wheel drive and rear neutral.... He got busy with the dremel

Now the pills will allow FWD only, but not go into L and H at the same time.... we kept that interlock!

We realized we had the wrong bearings to assemble the front output assy...so we got them at Carquest and NAPA.... here we are heating them up in Steve's new toaster oven... the just slid on the shaft with no problem!!

Front output shaft assy installed....

Cover and shims installed

I had recently bought WildHorses Extreme Duty Output Shaft assembly with corrected speedo gear... here it is installed!!

Next was the input shaft for the intermediate housing....

We realized that the kit ordered by Steve and me, neither had the required O-ring for the this shaft... off to Ace Hardware...

Steve getting it all lined up .....

All assembled except for the inspection cover....

PAINTED and READY TO GO IN THE BRONCO!

Can't wait to get it installed ..... Steve thank you again for your knowledge, skills and patience.......!!!!

 

[Viperwolf1]

My early '73 T-shift case also had the J style front output. I think Dana phased in that change before the shift rail change. I actually prefer working on the J front shafts because you don't have to fight the snap ring. I converted mine over to J style rails. I see your serial number is only about 4,000 units before mine.

 

[sprdv1]

Love the aluminum mod, looks cool

 

[70_Steve]

My early '73 T-shift case also had the J style front output. I think Dana phased in that change before the shift rail change. I actually prefer working on the J front shafts because you don't have to fight the snap ring.

I wish there was a way to tell beforehand that it had this style front OP shaft. Would have save 45 minutes or so of frustration trying to slide the bearing over to get to the snap ring, not to mention having to run all over Phoenix trying to come up with the correct bearings. I've only ever worked on a t-shift, and it had been a while since I'd done that. I think now I could tell the difference by looking at them. Also learned that the input shaft bearings are a different ID between the J and T shift.

 

[MY 4 BY]

Nice touch with the aluminum cover. I recently rebuilt my T/C and am having trouble with an oil leak on the rear cover for the front out put shaft. The shims leak. The bolts are properly torqued, but oil is getting by the shims. Did you guys use any sealant on yours? I'm reluctant to do that, because it will change the preload on the bearing.

 

[70_Steve]

Nice touch with the aluminum cover. I recently rebuilt my T/C and am having trouble with an oil leak on the rear cover for the front out put shaft. The shims leak. The bolts are properly torqued, but oil is getting by the shims. Did you guys use any sealant on yours? I'm reluctant to do that, because it will change the preload on the bearing.

I used a copper gasket spray. I initially set the endplay at .001 (spec is .003-.005). Disassembled and layed the shims and cover on some cardboard and sprayed one side. Reassembled and checked the endplay, and only gained .0005.

 

[Viperwolf1]

Nice touch with the aluminum cover. I recently rebuilt my T/C and am having trouble with an oil leak on the rear cover for the front out put shaft. The shims leak. The bolts are properly torqued, but oil is getting by the shims. Did you guys use any sealant on yours? I'm reluctant to do that, because it will change the preload on the bearing.

I use a thin coat of high tack on the shims. There shouldn't be so much that it gets pushed out when tightened. It doesn't really affect the thickness once tightened, I've measured it.

 

[farnorthdan]

My 73' has the miss match of parts, the tranny shop i took mine, had a fun time sourcing the different parts....


dan

 

[mattt]

Nice work! The custom cover looks sweet. Thanks for posting all the pics.
One question, when grinding the shift rails for twin stick, is there a specified location where to clearance them for independant twin stick? I've got my T shift mostly apart right now for minor rebuild, clean up, new gaskets/seals and twin stick conversion without removing the interlock pills, and every write up I've read does not give any dimensions where to grind the rails.
I wasn't going to replace bearings or go for the full rebuild since my case worked fine and didn't pop out of gear....so when I put it back together I should be able to put the shims back as they were with no issues....right? Will any of the tolerances change just from dis-assembly or re-sealing? Thanks.

 

[70_Steve]

One question, when grinding the shift rails for twin stick, is there a specified location where to clearance them for independant twin stick? I've got my T shift mostly apart right now for minor rebuild, clean up, new gaskets/seals and twin stick conversion without removing the interlock pills, and every write up I've read does not give any dimensions where to grind the rails.

Here's a link to a great article on modifying the shift rails. There's no specific dimensions, but if you'll notice, the front shift rail has one long detent for the rods, and the rear shift rails has two seperate ones. Lay the shift rails next to each other and lay one of the detent rods (pills) at the end of the front shift rail detent. Then mark the rear shift rail so that it is possible to have the detent rod line up with, say, the front of the front shift rail detent, and the rear of the front detent on the rear shift rail.

http://www.wt4x4.net/tech/twinstick.htm

I wasn't going to replace bearings or go for the full rebuild since my case worked fine and didn't pop out of gear....so when I put it back together I should be able to put the shims back as they were with no issues....right? Will any of the tolerances change just from dis-assembly or re-sealing? Thanks.

I'd just check the end play when I'm done to make sure it's within spec. Put it together dry to verify the end play, then seal the shims and bolt it up. Don'd forget to put a sealant on the bolt threads for each bolt that goes through to the inside of the case (which is just about all of them!)