I changed fluid in my front and rear diffs a few weeks ago. This past weekend I made a long trip w/ a couple of horses (probably really getting the fluid hot for the first time since i changed it) and a seal where the driveshaft inserts into the rear diff, sprung a leak. I of course checked the fluid level and it was still about 1/2" below the fill hole. How bad can a leak like this get and how hard is it to fix? Is it something I can ignore as long as fluid doesnt start drip dropping out and the fluid levels seem good or do I need to change it immediately?

Thanks for the help, Drew

 

Jack the rear end up = placing the jack underneath the diff.

Grab the driveshaft and try to move it up and down - see if there is play by the yoke - it could be a pinion bearing.

 

I'm missing something here. If you jack up the rear of the truck via the pumpkin your not doing anything to reduce pressure on the drive shaft correct??? maybe if you jack up the truck via the frame, or am I way off.

 

Way off, you are trying to reduce the pressure on the tires, there should be no pressure on the driveshaft, it will slide in and out depending on the driveshaft angle.

 

No worries (knock on wood) a very knowledgeable mechanic friend of mine checked it out this evening and siad it was just the seal--Im going to do what little I can to help him change it for me this Sunday.
Thanks, Drew

 

Be sure to have a puller on hand and do not be surpried if the yoke has a groove worn in it.Your option will be to find a wear sleeve or buy a new yoke at that point.IRRC you will need a 1 5/16 very thinwall socket.

 

Thanks for the heads-up info.
Drew