On my '91 4Runner..... is the transfer case output shaft seal made out of rubber? Still running strong at 493,000 miles but have a really slow leak from the seal mentioned. Might be worth the effort to drop in a Sealer since the leak is so slow and if the seal is rubber. Any experience on this? Thanks

 

I wouldn't put anything but ATF in my transmission. I have seen these seal swellers work on old seals for a bit, then the seal becomes brittle and falls apart.

That's pretty impressive mileage. I would just replace the seal and not risk shortening the remaining life of the trans.

 

I think this may be the seal needed (90316-40001):
https://parts.toyota.com/p/Toyota__/...031640001.html

 

Thanks for responding! I thought it might be the output shaft seal but after a better cleaning, I'm not sure where it's coming from..... a little history over the past several months is probably required;

Several months back, shifting became erratic. Would downshift from OD into 3rd at highway speeds, delayed shifting from 1st to 2nd. You name it it was doing it.
I did a drain and refill 5 times and each effort resulted in a little better shifting but still erratic and unpredictable. THEN, whatever was wrong was cleared and it now has been running/shifting like new for the last 2 months. It was so bad before that on D&R 4 and subsequent 5 I added the Lube Gard RED which is highly recommended and I too recommend it as it did fix the problem. I can;t believe how good shifting is now and it has a little under 500 miles since the last D&R with perfect shifting.

Since the RED has cleaners, I'm thinking the new Dexron III with the RED has caused some other build up to be removed causing the leak. The leak is only after driving. Wipe it off and it does not return until you drive it again. It;s really more of an "ooze" and could probably go unnoticed if I wasn't looking at the right place at the right time!

So, the plan is to do a through cleaning and try to find the spot where it;s coming from and make a decision as to how to resolve. I too have always been skeptical on additives but the shifting was so bad before I added the RED I figured it couldn't hurt..... as it ended up, it fixed it!

 

Thank you for posting your results with the Red and shifting improvements.
good luck with the leak, look forward to seeing how you fix that.

 

Ok, got it cleaned up enough to see what was leaking. Left (drivers side) on the transfer case (rear-ish) there is a weep hole. ATF is coming from this hole. It is just a molded area in the case (aluminum) with a hole in the center. What does this indicate? It's still the A340H unit in case we forgot!

 

Any way you could post a pic? just went and looked at my transfer case on my 340H and didnt see a weep hole or anything

 

A pic would definitely help. I haven't had time to look on my truck due to work, but I did look through the FSM and didn't see anything like you describe.

 

I'll see if I can get a pic posted!