QuestionI have a 51 Studebaker Champion with an automatic transmission. The front of the differential leaks fluid. I have owned the car for about 6 months. It sat on display and was not a problem. I drove it a few weeks ago and developed a very bad leak. I filled with normal 80 90 wt. grease and drove it for about 20 miles, thinking it was just from sitting. Now it leaks badly without being driven. May I ask how hard it is to replace the front seal or if there is something else I should be addressing. I am not a mechanic, but have good basic knowledge and a rack to work with. Any direction is very much appreciated. I wiped the area good and dry last nigt around the metal plate where the driveshaft enters the differential and have let it sit until I return. Thanks in advance for your time.
Sincerely,
Mark
AnswerThe front seal of the differential is called the pinion seal. It is not complicated to change, but it does require a torque wrench to re-install the companion flange after you change the seal. You also need to carefully inspect the surface of the flange that the seal rides on - if there is a groove worn in the surface, the new seal will probably leak also. The cure for this is to install a "repair sleeve" which you can buy at the same place you buy the new seal from.
I'm concerned that you may not be using the right grease in the rear axle - the preferred grease is GL-4 (or lower number) SAE140W grease - do not use later grease such as GL-5, or variable viscosity grease such as 85W130 - that is too thin for your car, and also has additives that are not good for your axle.
However, even with the wrong grease, a serious leak means a bad pinion seal.
If you do not have the shop manual for the car, I strongly advise you to get one; then follow the directions for this operation. Any of the literature dealers should be able to supply this for you. I use Ed Faxon at www.faxonautolit.com, but there are many others.
A 51 Studebaker with automatic transmission is a rare car indeed! Good luck with it.
Dick
