bungled transmission seal repair?

[bjudd]

I recently had the rear transmission seal replaced on a 5 sp. ZF.  After repair it has a very slight leak (couple drops after a drive).  If I clean the whole area with brake fluid and dry it I begin to see leakage from the seal after about 20 minutes of driving.  The repairman says "that it is to be expected because of wear to the driveshaft, etc".   Does this sound accurate or like an excuse?   I don’t know if I should be concerned.      

   Thoughts?

bjudd
1969 280 SL 5 sp

[al_lieffring]

I havn't ever had a ZF apart, but usualy a shaft seal will also have an oil-slinger on the shaft to divert the oil away from the seal and reduce the volume of oil trying to escape. Missing? Installed backwards? ZF didn't include a slinger in the design?  
Or there could be a wear groove in the flange deep enough that the seal no longer can make contact.

Al



113-042-10-014715
built 11 Jan 66
904/396 blue, Ivory Tex
condition- rust bucket

[George Des]

I've got the ZF 5 Speed as well. I also have a small leak but in my case I believe it is coming from the speedo drive seal. Many of the ZFs have a cracked rear cover at the speedo attachment point due to some overzealous tightening of the clamping screw. Gernold told me he has also seen this. In my case I was able to effect a repair of the clamping joint to a point with the box still in place using some fiberglass cloth and JB Weld but I'm sure the seal in there also needs to be replaced--this would have necessitated pulling the box in my opinion to get it right. I've done a few of these on the 4 speed box and they are a real bear to get at and pull and replace while the box is in. So in the meantime. the bottm line is, I still have a very small leak that I've learned to live with until i pull the box again and do it right--this will include having the rear cover properly repaired by aluminum welding it and replacing the small seal. You might want to check if this is not where your leak is coming from. Just make sure you keep an eye on your fluid level--it doesn't hold much to begin with.

George Des