T90 Leaking

My 57 has a T90 (A I believe). It was rebuilt a while back, but has always leaked some, more so recently. I see stains gather on the driveway in just a few minutes after driving or sitting over night. My jeep has a 283 SBC in it. I was thinking of switching out the tranny to something better, that won't leak. I have a Warn OD and the Dana 18 T-case. I suppose I could drop the OD if I went with a 4 speed tranny? Thoughts or recommendations that allow me to keep the Dana 18?
Thanks,
Paul

 

hard to tell. There is oil around the tranny and tcase, also some oil dripping slowly out of drain hole of flywheel cover. I am assuming sinc the tranny is so old, that is why it leaks? How can I tell if it Tcase only? My tranny was rebuilt from a reputable guy.

 

alright...will work on that...thanks for the input

 

A rear main seal from the engine would also leak from the bellhousing. Gear oil and engine oil smell distinctly different - Take some of the drip on your fingers and smell, and compare to the smell of your dip stick.

 

Don't assume. I suggest you make sure you really have a T-90. The Novak Guide to the Borg-Warner T90 Transmission

IIRC T-90s have a felt (?) seal on the input shaft, which should have been replaced when it was rebuilt.

Novak has a rebuild guide that specifically addresses front input leakage and sealing. The Novak Guide to Rebuilding the Jeep T90 Transmission They say that a converted transmission used with a V8 engine should have a conventional rubber/neoprene seal. They also discuss the use of a sealed front bearing to cure this leaking.

 

Rear main leaking and dripping out the bottom of the bellhousing will blow back on tranny and transfer. Like Tim sez. Is it engine oil or gear oil?

 

Will check smell when I get home. My tranny T90 was rebuilt by Herm. Verified T90. Engine was rebuilt at same time, but still could be rear main seal. Engine is stock 283, not a modified power house.

 

Would a tranny additive help, for leaking that is like Lucas or other? Or is that just putting a bandaid on a problem?

 

Any V8 is a lot of power for the T-90, but it would not make it leak. Instead it would go bang. A loud bang.

There are lots of Jeeps out there that were converted to V8 power that still have the T-90. Even early Wagoneers with T-90s got a 283 or 289, and survived. It'll be fine if you don't abuse it.

The transmission additives contain solvents that make the seals swell. This tends to help automatics more than manual transmissions, because the hydraulic servos in the automatic have rubber seals that harden and wear out. Even then, it's a way to get a few more miles before a rebuild, not a real cure. If you have a felt seal on the input, it will do nothing. Might make it leak more, because the oil will be a little thinner - assuming this is gear oil.

 

I'd fix the leaks. Your drivetrain is a good setup, just needs some TLC. There's a lot of experience and good advice on this site on how to fix it, through experiences. Some will say leak free T90 and Dana 18 can't be done, I disagree because I'm driving a '46 Willys CJ2a and and a '71 CJ5 that are leak free and I'm not afraid to park on my new concrete driveway.

The CJ2a I've had the tranny and TC out 3 times in last 2 years going after leaks, each time learning something new to stop an annoying leak. Here's a good thread on TC leaks.
D18 Leaking - Advice Please

Your T90/bellhousing leak may be caused by cluster gear counter shaft where it exits the front case below the bearing retainer. Easy to test, with tranny out and top cover off, put some GL1 mineral oil in it and see if it seeps out around the shaft. If so, drain, clean it good with lacquer thinner and put a couple coats of that Gear Oil RTV over it. I haven't had problem with bearing retain seal, just use good felt washer or you can get seal instead, and then use the RTV to seal retainer to front of case.

I use Gear Oil RTV between T90 and TC as well, just make sure you're bolts are good and clean and have RTV on them as well, especially the lower two. Same with your OD to TC.

TC pan can give folks problems too, one of mine I used the "Right Stuff Sealant" to fix it. Look at thread above for shims and output yoke sealing.

It's not that difficult pulling and putting in the tranny and TC. My technique is pull them both together, same for installing. I use ATV/MC lift, with crossmember still attached to tranny, 2 racket straps to hold in place. Not that hard, just takes a little time, right technique and sequence, don't get in hurry, think it through and it won't be that hard.

Good luck and let use know what you decide.
Mark