I just had my 8¾˝ rear rebuilt. I went from a one-legger to a Cone-type Sure Grip, 3.23:1. The diff is a NOS cone Sure-Grip that I purchased many years ago. My concern is the wheel bearings. The guy who rebuilt it used Green bearings stating they are better than the originals. My friend states the tapered Timkens are the way to go and even sold me a pair of them. My question is will the Timken work on the new Yukon axles and how do I set them up? I was going to take them to a local garage and have them pressed (the stop collar) on. One more thing, where can I get some of the Mult-Mileage grease for packing the bearings and to use when reinstalling my torsion bars?
Your friend is 100% correct. The ball-type wheel bearings are only suitable for straight-line (drag racing) use. They have a small fraction of the side-load capacity vs. the tapered roller OEM setup. There are two concerns when retrofitting wheel bearings back to the real deal. First, is the end of the axle smooth? It will be carrying cornering (side) loads to the opposite axle via the diff’s thrust block or buttons. Some aftermarket axles have a centering hole and/or a raised lip, which is NG. Yours (see pix, left) appears fine. The second is length. For stock bearing use, there can only be about 1⁄8˝ variation from stock. The only practical way to know is to install them and set, or try to set, the endplay. Setup instructions are in the FSM, and I have written about this almost ad infinitum, so I’ll just give you a brief overview:
- Press on left retainer (w/ outer seal) and right adjuster (also w/seal), bearing, packed with wheel hi-temp bearing lube (not MML), and collar. Be sure to not damage seal surface on axle. Seal lips face in.
- Install inner (housing) seals, bottomed. Lips also face in.
- Slide axles in, use caution to not slice inner seal with sharp splines. Install nuts (only install 4 on right side).
- Tighten right side adjuster until there is zero endplay, then a bit tighter. Start engine, engage trans, spin propshaft for a few minutes. Stop. Whack both axle ends with a rubber mallet, dead-blow hammer, or BFH and 2×4. Repeat. Can’t get play zeroed out? Axles too short.
- Set endplay (loosen adjuster) to approx. 0.005-0.008˝ or about 1-2 notches from zero point.
- Install adjuster lock and washer/nut.
- Drive 100,000+ miles.
MML can be had at any dealer, P/N 4897841AA. It is the stuff for steering and suspension joints, T-bars, clutch fork/torque shaft components, etc., but not for wheel bearings. Green Snot hi-temp WB grease is P/N 5083150AA