|Leaking Driveshaft Yoke|
Written by: Mike Ervin
I had a problem that I thought was a rear tranny seal leaking. I probably changed the seal three times, and it still leaked. I had the truck up on jack stands working on the exhaust for a few days with the front of the truck higher than the rear. This thing was leaking pretty bad. Enough to cause a puddle on the floor. Then I found the answer to my problem in Car Craft magazine. This is a very easy fix to an annoying problem. I never knew this existed. Learn something new everyday I guess. Below is a snippet of the article.
Remove and Replace
First thing. NEVER EVER get under your truck without some good jack stands to support it. We want to keep you alive.
To remove the extension housing, you will need to remove
the driveshaft. Be prepared to catch any tranny fluid that comes out. Mark the
location of the rear u-joint on the pinion yoke at the rear so you can install it in the
same location. This will make sure it is not installed out of balance. You
will need to pry the u-joint out of the rear yoke a little. Be careful to not let
the cups fall off the u-joint. Next remove the speedo cable from the sleeve in the
extension housing. Now unbolt the extension housing from the transmission.
Again catch the transmission fluid. Make sure the rubber seal on the extension
housing is intact. You should see something similar to the above photo depending on
what type of transmission you have. Make a mental note of where the metal cup is
located at on the output shaft and slide the cup off. The O-ring, (pn
GM3764601) will be in the groove inside the cup. Replace the O-ring and slide
the cup back on the shaft. Try to get the output shaft in the center of the cup as
best you can. This will let the driveshaft yoke go all the way in without it hitting
the end of the cup. The rest is the reverse of removal. To help from ruining
another O-ring, use a little tranny fluid on the outside of the yoke before sliding it
back into the transmission. This will also help save the rear seal from damage.