If you choose to rebuild your own rearend, Randy's Ring & Pinion put together a comprehensive 378-page book on differentials that is a great resource from how and why, identification, and modification, which is nice to have in any library whether you're building a rearend or not. Also, the installation kit instructions from Yukon describe the rebuilding process fairly well, but even being a hands-on guy, I still left this one to the pros.
Once you get your differential good to go, it is important to follow either the manufacturer's or service center's break-in procedure to ensure that all the work and your hard-earned money isn't wasted. Randy's and Unitrax's break-in sheets basically mirror each other, which is comforting. Both outline the following:
* Only use a premium national brand 80W-90 or 85W-140 GL-5 gear oil, and make sure to add the proper friction modifier fluid if you have a limited-slip or posi unit and every time you change the gear oil. Make sure the drain plug is tight.
* Drive the vehicle for 15-20 miles and then stop and let it cool for 45 minutes. Avoid aggressive starts, hard stops, and driving long distances at a steady speed during break-in.
* Repeat the previous step once. Do not tow for the first 500 miles, and do so gradually afterward. Avoid wide-open throttle acceleration for the first 300 miles.
* Change the gear oil after the first 500-2,000 miles with the same type of fluids.
Again, check with the manufacturer or service center, but following their break-in procedure should give you years of trouble-free use of your fresh rearend. Next month, we'll show you some tips for putting the rearend back in your '67-72 Chevy truck.
Without further ado, Greg at Unitrax got down and dirty disassembling our GM 8.875 truck a
With the diff cover off, Greg marked the carrier main caps for both position and side with
Next, remove the pinion shaft retaining bolt, followed by the pinion shaft, and then the C
The pinion usually requires a good bit of force to come out of the housing. If you are goi
To get the axle bearings in the ends of the axle flanges out, it is easiest to come in fro
It looks like the passenger-side seal was on its way out, judging by all the grease around