speedometer gear leak

I have noticed a pretty good leak where the speedo cable connects at the transfer case
(D18). I havent put a new cable on yet but I noticed on a spare gear that there is no seal on the shaft.
Is there a seal with a new cable? If not, what keeps the oil in?
As always your help is appreciated.
Tommy

 

there should be reverse spiral grooves etched into the driven gear shaft to keep the oil from coming up; I don't believe there was ever a seal inside the adpater for that purpose; I could be wrong though.

 

I use silicone on the threads and such. They all leak BTW.

 

Thanks for the replies. I did notice the threads on the driven gear shaft. I wonder if I need to replace the gear to get a tighter fit on the shaft. This one leaks pretty bad. Will this leak occur because of an over full T case?
Thanks,
Tommy

 

They leak because of the oil level and the housing is low down. Remember, the housing is low down because of the location of the output as compared to the oil level. Later model 20 and 300 transfer cases had a seal there that helped. IIRC the threaded in housing was machined with a step for the seal..... Nickmil

 

John, If the Transfercase is overfull it will leak in all kinds of places, it can even blow out formaly good seals. Fix that first. I have not had a problem with a major leak out of the speedommeter cable. Yes they seep a little, but not a major leak. Fix the overfill and what ever caused it. Then drive it for a while, a few days, then recheck your leak. I will bet is will be much improved. Matt W.