Differential Service

Grit dog wrote:

EMD360 wrote:
Recommended differential service is between 50,000 and 60,000 miles. So it was time. They just replaced the gasket and the fluid. Because it was just service the warranty does not cover it. Didn’t hurt to ask. I still don’t have the RV though because they were not happy with the alignment so sending it back for a rear axle alignment. These look like they are relatively uncommon. But if the steering wheel is off center or there is pull one way or the other I guess it’s possible the rear axle can be adjusted. Can’t find much on it on Google. So the shop that does alignment for them can’t get to it until next week. It’s drivable they say but I didn’t want to experience a problem after all the work I’ve had done so I won’t get it until 2022!

Fwiw, unless there are some extenuating circumstances not mentioned, it is virtually impossible to knock the rear axle of a solid axle vehicle out of “alignment” and it is 1000% not adjustable. If for some reason there is a gross misalignment or bent axle, it is a mechanic shop or body shop job.

Or in other words, you’re likely being sold a bill of goods on the rear alignment. Beware.

Leaf springs have a center pin that protrudes out and a saddle may sit on and be centered by that pin.The axle sits on that saddle and is held together by the leaf spring u bolts. If the pin fails the axle can move. Occasionally you will see bob tail or pick up trucks doing the doggy walk down the road, favoring one side or the other.

FWIW fact: I performed wheel alignments on semi trailers and the front axle was 1/4 inch longer in measurement from the king pin on the drivers side and the rear was adjusted to be exactly the same distance from the front axle. This was to keep the trailer axles favoring the crest of the road. Often a trailer came in for wheel alignment as the driver noticed the trailer "dog tracking" A broken center pin was the first item we checked.