Leaking T90

I just finished rebuilding my T90/D18 as per ShnitzlHaus. I used a sealed front bearing but now, after coupling it to the bell housing and fill it with oil I have a small leak in between them. What did I do wrong?

 

one guess . cluster gear shaft

 

Should I pull the T90 out? Is there any way to seal it from the outside, I mean without totally disassembling the transmission or should I be like any other jeep owner and enjoy the leaks?

 

X2...yeah, I am with Ron on this one. There was a thread on this awhile back where someone had the similar issue. Some of those cluster gear shafts fit tighter than others in the front trans bore. I think it is originally tapered slightly for a friction seal. Years of banging around in there, or someone at some point driving it out the wrong way kinda un-does all that. Anyway, what I do during assembly before seating the shaft all the way is just barely start the shaft into the front bore, clean the bore really good and put some anaerobic sealant in there, then seat the shaft. I also put a dab of sealant on the front of the trans case where the shaft comes through just prior to bolting it all up to adapter or bell housing depending on the application.

Already being assembled, you may be able to let the oil drain real good, slide the trans back a bit, clean up the face really good with brake clean, then apply a bit of sealant or RTV to the face of the trans where the shaft comes through. Don't overdo it...and I'd let the RTV set-up for 30 min or so before bolting it back up for a better seal.

I will try to look for the other thread...or someone else may chime in.

 

No, I just finished and put fluid in it.

 

I sealed everything as good as I could. Maybe the cluster shaft was not sealed as good. I do not think is from the engine, I will try to take pics tonight.

 

Don't scare me...

 

When it gets to running temperature that day when I get to fire my engine again, If it leaks a lot I will take it down and seal it with some Permatex and add a full-face gasket in between the transmission and the bell housing.
I might even give it a try to a oil leak sealer...

 

You are probably right. I will take it down and see what I can do about it. Do you think a full-face gasket in between the T90 and the bell housing in addition to some permatex will solve the issue?

 

It was my first time doing it...
I have no frame of reference but if I recall correctly it was a fairly tight slip fit. I had to slightly tap it in.

 

This is just a crazy thought, and I can’t remember if both mating surfaces are smooth, but would it help to run a thin gasket or RTV between the trans and bell? Volvos utilize a gasket there, but it’s mainly because the cluster gear bearings are shimmed against the bellhousing, so oil needs to be stopped there. I can’t think of a reason why it wouldn’t work here too.

 

When I put my trans together and put it in, everyday I would find a teaspoon of oil on the floor under the trans. I took it out looked it all over, could not find the leak. after trying it out three times, I pulled the trans, set it in the sun and waited for it to get warm. When it got good and warm in the sun, I saw a trickle down the front of the Trans case from the cluster gear shaft, I drained the oil out, cleaned the front of the trans case with Brake Clean and put a dab of Permatex on the end of the shaft and put it back together, problem solved. I have redone a lot of transmissions in the past, and never had the cluster shaft leak at the front, I think they are slightly tapered to seal the shaft? But I learned now and will seal all the shafts from now on. Good Luck.

 

Napa auto parts sells fluorescent oil dye that can be added to the oil. They also sell a reasonably priced black light that is dc powered off the vehicle’s battery. Drive the Jeep to get everything warm then shine the light on the trans. No doubt the oil path will be visible.

 

Just take it out, it's easier now than later I got really darn good at slapping mine in with my rebuild. Last pull off the engine to shim and recount cluster bearings to back on the engine was so casual I barely remember her name.