Oil leak from rear section of transfer case.. Maybe Speedo unit the cause? (1 Viewer)

[viclava]

I have what appears to be on some days is a pretty good dripping going on from rear of transfer case right below where the speedo assy is. Can anyone advise what is involved in fixing the seal(s) inside this assembly. I'm sure that I'm not the only one who has experienced this on my 94 80 series.

It looks like its possibly coming from that speedo housing. Are there any tutorials or pics of parts with part numbers that are usually associated with this fix? Any hekp is much appreciated.

Cheers

 

[bloc]

Common problem. There are two parts to that unit.. a round assy that goes into the rear of the t-case.. this has a shaft inside with a gear on the end that turns via a gear installed on the rear output shaft. The other part on a 94 is the electronic adapter.. it attaches to the first part with a knurled ring, and converts the shaft signal from the first part into an electronic pulse via the connector attached to it.

In the first cylinder part there are two seals.. an o-ring that goes around the body of the speedo.. known to get hard and leak.. and an inner shaft seal. The outer is pretty easy to do. You'll need to drain the case, remove the small 12mm bolt and retaining tab, then slide the whole thing out. remove the o-ring, roll a new one on, reinstall being careful not to cut the o-ring.

If it still leaks then it needs the inner shaft seal. It is the same format as a front or rear main seal, but very small, and deep inside a well. Remove the electronic part if still attached, slide out the retaining clip, and the shaft will slide out of the unit. I had a hard time getting my old one out.. but finally did. This is what cured my speedo leak finally.

o-ring part number: 96711-24030
Inner seal number: 90310-09001

both are pretty cheap.

 

[viclava]

Common problem. There are two parts to that unit.. a round assy that goes into the rear of the t-case.. this has a shaft inside with a gear on the end that turns via a gear installed on the rear output shaft. The other part on a 94 is the electronic adapter.. it attaches to the first part with a knurled ring, and converts the shaft signal from the first part into an electronic pulse via the connector attached to it.

In the first cylinder part there are two seals.. an o-ring that goes around the body of the speedo.. known to get hard and leak.. and an inner shaft seal. The outer is pretty easy to do. You'll need to drain the case, remove the small 12mm bolt and retaining tab, then slide the whole thing out. remove the o-ring, roll a new one on, reinstall being careful not to cut the o-ring.

If it still leaks then it needs the inner shaft seal. It is the same format as a front or rear main seal, but very small, and deep inside a well. Remove the electronic part if still attached, slide out the retaining clip, and the shaft will slide out of the unit. I had a hard time getting my old one out.. but finally did. This is what cured my speedo leak finally.

o-ring part number: 96711-24030
Inner seal number: 90310-09001

both are pretty cheap.

 

[viclava]

Ok, thanks for the reply. Still a little confused regarding the last part. You reference it being like the front or rear main seals.

Are both the seals on the actual speedo part that slides out from the side of the transfer case, or is one inside the transfer case? I do better with pictures.

Thanks again.

 

[Tools R Us]

Maybe shoot/post pictures of the leak? If it's the speedo output, it's stupid simple, one bolt deal.

 

[viclava]

Hopefully it's visible in this pic

 

[890man]

My 94 was leaking from the speedo housing. Very simple fix. Remove bolt. Remove unit. Replace oring. Replace unit. Replace bolt. Enjoy a beer. Finishing the beer will take longer than fixing the leak.

 

[viclava]

My 94 was leaking from the speedo housing. Very simple fix. Remove bolt. Remove unit. Replace oring. Replace unit. Replace bolt. Enjoy a beer. Finishing the beer will take longer than fixing the leak.

That's my kind of fix...

 

[viclava]

Anyone have a blown up view/schematic of the speedo housing removed that shows me what I'm going to be replacing?

 

[Tools R Us]

For Sale: - 40, 50, 60, and 80 series FSM for a hell of a price.

 

[bloc]

Thing is, the "easy" seal everyone talks about didn't fix my leak. When I said like a Rear or Front main, I mean that it is a rubber seal that fits around a shaft and holds back fluid. In this case it is inside the little speedo gear assembly, not in the transfer case. That seal is about a half inch across total, and somewhat difficult to get out of the housing due to how deep the hole is where it is located.

I dug around both my FSM and parts diagrams and can't find anything that'd be useful. I have a spare transfer case in the garage and will try to find some time to pull the VSS and get some pics.

 

[viclava]

Thing is, the "easy" seal everyone talks about didn't fix my leak. When I said like a Rear or Front main, I mean that it is a rubber seal that fits around a shaft and holds back fluid. In this case it is inside the little speedo gear assembly, not in the transfer case. That seal is about a half inch across total, and somewhat difficult to get out of the housing due to how deep the hole is where it is located.

I dug around both my FSM and parts diagrams and can't find anything that'd be useful. I have a spare transfer case in the garage and will try to find some time to pull the VSS and get some pics.

I think I have the I tire now. Thank you for you description