View Full Version : tcase seal removal/installation?
07-12-2006, 11:42 PM
Anyone who's had a leaky output shaft on their t-case and rebuilt it whilst being on the truck, any tricks to removing that sucker and reinstalling the new one? The output shaft protrudes about 6 inches past the seal, making it kinda hard to get a seal puller/screwdriver in there. Ideas?
07-13-2006, 12:01 AM
Remember to drain the t-case before you pull the brake drum;)
07-13-2006, 09:38 AM
output? just pull the speedo housing and pop it off then. easier to tap new one in too.
07-13-2006, 04:26 PM
seal is easy as pie but I think the nod goes to Treeroot. I forgot to drain my cases before I pulled them for project reseal. :homer:
07-13-2006, 06:24 PM
Yeah, knew about draining the tcase :homer:. I haven't looked at it too close but if the rear half of that comes off (with the seal) then that will definitely be easy. If not then I have to work around the output shaft to the rear axle.
07-13-2006, 09:01 PM
Matt, it's really easy (compared to say, replacing the seal that goes between the tranny and t-case ;-). Unbolt front half of rear driveshaft, leave the diff end bolted. Swing it out of the way or bungie it up. Older rigs have cotter pin/castle nut, newer ones like your 77 will have a stake nut. You really should use a new stake nut, but the old one can be reused in a pinch, just not recommended. Nut is 27mm (I think) on yours, my 71's a 29 which I didn't have but 30mm worked.
As has been written, drain the t-case first ;-)
After the nut and washer are off, you can use a seal puller that looks kind of like a claw hammer. Just get in there and yank. You can get more clearance by taking off the e-brake by unbolting the 4 bolts that hold the backing plate to the t-case, but it's possible to do it without removing the e-brake, just more difficult clearance for the puller.
Ige's idea is a good one, but more stuff has to come off. In any case, since the shaft sticks out so far, you can't use the socket method of installing the new seal unless you take the speedo housing off as Ige suggested. I just tap carefully around the edges with a lead shot filled rubber mallet. Keeping the frame square is the trick. Smear some grease onto the lip of the new seal before you put the e-brake drum back in, and don't forget to use sealant on the splines of the output shaft when you put the e-brake drum back on!
07-14-2006, 12:20 AM
Okay, didn't feel like trying to take off the speedo housing (thought that there might be another gasket to have to replace if I did that), so I just drilled two holes in the seal, cranked in two sheet metal screws, then used a claw hammer to pry the seal out. Worked like a dream. I guess I still don'd see how you get a seal puller in there with the shaft in the way.
Getting it back in I tried first to cut a hole (smaller than seal, bigger than splined shaft) in a piece of plywood then set it against the seal, then set a pipe bigger than the shaft against that and bang on it. Too many things to hold up, so I ended up just really carefully tapped around the edges like Jeff said, just like wheel bearing seals.
Sealant on the splines of the output shaft before putting the drum back on? Didn't know I had to do that, figured the seal would stop any/all oil from leaking out?:confused: Anyway it's basically back together, might have to dive back in to seal that if it's necessary. I hope that stops my leakage, I'm sick of adding oil to the t-case every few weeks...
07-14-2006, 06:34 AM
An extra rear DS flange makes a handy install tool!
Yep, put some sealant on the output shaft so your parking brake seals to the shaft...
How is your input shaft seal? Are you pumping fluid into the tranny?
07-14-2006, 07:44 AM
I was actually going to check the tranny next to make sure everything's okay....I'm pretty sure it is though.
07-14-2006, 08:43 AM
Sealant on the splines of the output shaft before putting the drum back on? Didn't know I had to do that, figured the seal would stop any/all oil from leaking out?:confused: Anyway it's basically back together, might have to dive back in to seal that if it's necessary. I hope that stops my leakage, I'm sick of adding oil to the t-case every few weeks...You WILL leak past the splines. Trust me on this. The seal is betwen the e-brake drum and the speedo housing (yes, you are right, there is a gasket between the speedo housing and the t-case housing). But the only thing to stop 90wt from getting past the splines is the big flat washer under the nut, and it won't seal. That's why the factory puts red RTV sealant on the splines.
07-16-2006, 10:42 PM
Okay, so I slimed the area underneath the big spacer with some sealant and tightened the nut down...should work. Then after I got the driveshaft back on (after having to remove it already today since I thought I was done last week, thanks guys for catching me and telling me about the sealant), I remembered that I hadn't staked the nut :doh:. Off came the driveshaft for the third time this project:rolleyes:
Also the transmission is not getting overfilled by the tcase, so here's hoping I found the leak!
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