I have a light leak at the differential where the drive shaft enters, and also another very light leak at the transfer case of the drive shaft. Is this an easy process to drop the driveshaft and replace the seals? The truck is a '98 with the 8.8 rear, manual tranny if that matters. Any special tools and/or pitfalls?

I do get a bit of vibration while going down the road. But it doesn't bother me and is probably not because of an out of balance drive shaft or wheels, but because it's a short wheel base truck with the Off Road package (stock 17" wheels). When I hit a smooth stretch of pavement it seems to be smooth. My friend has the same year of truck but extended cab and not Off Road pkg, his rides like a Lincoln, smooth as butter at all times. I put the best Monroe shocks on it, that are supposed to smooth out the ride and at the same time decrease lean in turns. They did nothing they advertised, truck rides and leans the same far as I can tell.

At maybe 90,000 or so the rear end started making a little noise. It only does it under light load (cruising), not when accelerating or decelerating, and it's not bad but getting more noticeable. I don't suppose there's anything to do about this, unless it gets real bad, or when my son gets his hands on the truck and wants to put monster tires on it.

Thanks if someone can answer about the drive shaft seals. Daniel

 

The ujoints in the driveshaft are probably going out. This is probably whats causing that shudder which is causing your seals to go bad. You should be able to drop off the tailshaft of the transfer case to change those seals out. As for changing your pinion seal, thats going to require pulling the axle shafts, carrier, pinion and then installing a new seal and then having to baiscally do a gear install. I wouldn't let this go for too long, especially the driveshaft. At least check the ujoints in that or your leaks will get worse and will be more expensive to fix. The front seal shouldn't be too bad, but the pinion seal is going to be a major PITA to fix.

 

Thanks for the response Sir. Since I have an 8.8 rear differential, does that require pulling the axles? I thought that was only on the bigger diffs.

Also, to get out the pinion and transfer case seals, are they just pried out with a screwdriver, and the new ones tapped into place?

Thanks, Daniel

 

Even though you have an 8.8 the shafts still have to come out. Its this way on any axle since the shafts spline into the carrier. As I recall thats how you replace the seals, you just gotta get the pinion and the tailshaft out to do it.