[LH Lead-Foot]

I will get the correct shim numbers from the garage soon. Going by memory is tricky sometimes, but I have done close to one hundred diff's over the years with my own last year. Chronic pain has it's disadvantages.

Pinion Nut; Use a chain wrench to wrap around the yoke or companion flange as it's called. Not all chain wrenches are long enough so measure if you have to buy one. Place a length of pipe around 6 foot on the handle of the chain wrench for leverage. 2" Conduit pipe from the home improvement store is cheap and will work fine. It will help you get the pinion nut off, but better yet, help you control the amount of force used to tighten it and obtain correct pre-load or rotational force on the pinion bearings. You will want to use a 1/2" ratchet or breaker bar and perhaps a cheater on it as well.

TIP: Use a nylon wire tie on the link of the chain wrench once you have it set. It has to come off frequently during pre-load to check where you're at.

If you are working while in the vehicle, use the lower control arm to lay to cheater bar/tube across as this will free up your concentration on the pinion. Use duct tape to hold the cheater in place temporarily as it will fall if you slip off the companion flange. Don't wear flip-flops.

Crush sleeves are cheap, but if too tight, they cannot be re-used. It will seem like you are wrenching until your arm falls off, but stop. As it gets tighter for the last time, check the pinion frequently as you tighten. It will be sloppy loose forever and when you don't expect it, it is too tight. Best advice is to wiggle the pinion around until you reach a point where it does not move sideways or in & out. This is when you go slow, perhaps 1/8 turn at a time, then recheck rotational force.

Rotational force is measured with a beam type torque wrench in inch pounds that specs vary depending on if you are using new or old bearings. Lube the seal and garden spring on the back only. I always used Loctite 518 red jelly on the outer edge of the seals seat before driving it home. Seal manufactures claim their coating on the seal is all that's needed, but I don't trust it and don't want to repeat the process due a leak.

Many may not know this, but the companion flange or Yoke should have sealant also. I use GM's liquid teflon thread sealant on the end of the pinion splines as well as the first 1/4" of the Yokes splines. It can leak pass it and come out behind the nut, especially if the breather tube on top gets plugged or as truck use a hose, gets pinch. This causes pressure inside a sealed diff housing from cold to hot.
Also, use bearing grease and pack the pinion bearings as well. They don't get lube unless the ring gear moves fast enough to throw gear lube (GL5) into the top cavity of the differential housing that captures the lube between the pinion bearings. It's just good insurance before you get out the door. This also true for the outer axle bearings. They are dry until you turn a corner and lube travels due to centrifugal force and a small amount is captured in the axle housings machined tube end.

Generally, A good starting place with shim packs is to use the OEM shims to start with. Do your pattern and adjust from there. Using new shim kits, measure the OEM shim packs with a micrometer then look for (+) or (-) mark in the new pinion. Add or subtract by thousands of an inch. I have had dozen of perfect patterns just by using the original shims, but then I was installing the manufactures dealership parts.