GM has had the same problem with the leaky slip yoke for years, its common on anything that has alot of suspension travel, thats partly why the Jeep guys use the old style "fixed" tail shaft joint(lets the drive shaft do the work). the GM folks did have a remedy, it was a special grease that one could buy and put in the slip yoke and it wouldn't wash out. plus it didn't dilute the trans fluid in the transfer case.
|