[ERA174]

I have some thoughts for your consideration. The lube in the main case should transfer to the output shaft housing. Your lack of a gasket at the output shaft housing to main case and an overly generous application of "silicone" may be restricting the lube. The transmission case could also be low on lube, which would restrict lube to the output shaft housing. A lack of sufficient lube in the output shaft housing would accelerate the wear of the moving components there. I'm thinking new speedometer cable, new drive and driven speedometer gears, new gasket at the output shaft housing to main case, clean all the old silicone off of main case to output shaft housing and only use liquid sealant at the bolts holding the output shaft housing to the main case, you don't want lube leaking past the threads and verify proper lube level. You may also want to check for excessive wear at the output shaft yoke to yoke bushing and yoke seal damage in the output shaft housing. All those items could have been effected by a lack of lube in the output shaft housing. If the output shaft housing is removed all the wear items associated with it are cheap and easily replaced. The preceding advise are the ramblings of a mad man and to be followed at your own peril! lol Hope this helps, good luck finding a solution.