Tcase rebuild troubles

I have recently rebuilt the broken Dana 18 that was in my FC-170 and it all went together pretty good for the most part except one last little thing. After I bolted it to the back of the T-90 I checked the yokes to make sure they would spin and they were locked down. I used the impact and backed them off a bit until they would move. I went about my merry way of filling the case with 90 wt when I noticed that not one but both yokes were leaking through/around the nut holding them on?! I just left if to see if it would slow down or stop and from the looks of it the case is now dry. What to do is the question. I am sure I am just overlooking something , but wanted to ask you guys for advice. Thanks for your time, Chris.

 

If you backed off of the yokes a little you have the bearings shimmed wrong. As for the leaking around the yokes you should use permatex or something on the splines of the yokes before you put them on, its seals around the splines.

 

In a dana 18 the bearing are pressed onto a shaft aren't they? Don't recall any shims, maybe that's my problem? Going to look over the situation again tonight.

 

There should be shims between the rear output housing and the case. These set the bearing preload/output shaft endplay. If no shims then the bearings will be too tight in the races and lock up the transfer case. Output shaft endplay according to my FSM should be .004" to .008". I set mine between .002"-.004" with new bearings and have had no issues. This allows for the increased end play that will happen as the bearings wear in. Nickmil

 

Thanks again Nick, will this follow suit on the front out put yoke as well? Now that you mention it, I do remember shims for the rear housing but not sure I remember them for the front??

 

There are no shims for the front, it is in a fixed position and the shims in the rear housing adjust both ends.

 

Q about the shims. If I kept the ones that came off in the same order do they go back on in that order?

 

Order wouldn't matter. It's the total thinkness of the shims. If you installed new bearings you will have to readjust the preload which may mean more or less shims of different thinknesses to get the proper preload as stated in previous posts.

 

X2 on lots of sealant on the front & rear output shafts & yokes. I also used copper gasket sealant sprayed on each side of each well cleaned shim used in the pack and factored in the sealant thickness to come up with the right end play. I ended up with .004 end play and no leaks in my case ( going on 2 years now ).

 

Thanks for all the info guys, gonna look closer this weekend

 

I’m about to pull/replace my TC rear cover as the brake lever is broken off. I kind of understand the shims but NOT how to measure the play. Is there a video anywhere or easy to follow description?

 

I found this little video on youtube. Not much different on measuring the endplay on the T-18 transfer case. I didn't listen to the guy's voice in this one. YMMV.

I think I bought the stuff I needed to measure this at Harbor Freight for about $20 give or take with a coupon. I measured it about 5x for a decent average.

x2 on the copper spray gasket for the shims. I used 'less' total shim after replacing the new bearings than what was originally supplied to get near the .004" that Nickmil mentioned above.

 

This should help...