Anyone have any suggestions on gears for a rear differential rebuild on a 97 1500 4x4 w/ 5.9? Running 285's on the wheels. I'm looking at changing from stock gears to 4.10's. Also, is it necessary to do both front and rear differentials when changing the gear ratio on one axle on a 4x4?

If indeed I'm going to change gears (which appears to be likely considering some of the noise I'm getting), any suggestions on where to get them and what brand?

 

Yes, you have to change both axles. Otherwise VERY much bad things happen cause front and rear tires will spin at different speeds.

Good place to get gears is West Coast Differentials- http://www.differentials.com/ That's where I got everything for the 4.10's I'm putting in my '97 2500. Good prices, fast shipping, and their salespeople are actually very knowledgable and helpful. Don't go cheap. Get a good brand name, like Dana/Spicer or Precision. the off-brands will wear much faster.

Are you doing this yourself? If so, you'll need a good dial indicator with a magnetic base, a good micrometer set, and a housing spreader would help. If you're doing it yourself, I'll give you a few tips to help make things go a LOT easier for you.

 

Thought about doing it myself, but space is an issue right now. I'm building a garage this summer, but might not be done in time to do it myself.

 

I did my first few in gravel driveways. Just have to be more careful and use more brake cleaner to keep the dirt off everything.

It's not that hard to do yourself. Here's some tips to help you out-

Take your time. Patience is everything. Begin with the front axle for practice. It's rarely engaged, so if things aren't 100% right, it's not that huge of a deal. Remember to put it in 4wd and take the pinion nut off FIRST while the truck will hold the pinion stationary. Or you can put a big pipe wrench on the yoke, but that's kinda a pain. When you take the carrier out, make sure you take the side shim packs out and mark them. They have to go back in the same sides when you reassemble.

Get a spare inner pinion bearing. Take it to a machine shop and have them hone 0.0015" out of the bore and mark it as modified. This will change it from a press fit to a slip fit. Use this bearing so you can take the pinion in and out and change the shim thickness without having to press the bearing on and off.

Take the pinion shims out and set them someplace safe, you will need them later. To get close to your correct pinion shim thickness, measure the thickness of the pinion head from the front face of the gear to the rear machined boss that the shims sit against with a good micrometer. Do this on the new pinion and the old one. Whatever the difference is between the old pinion thickness and the new one is what you have to add/remove from the old shim packs for the right pinion depth. Adjust the original pinion shim pack for your measurements, then assemble with the modified inner bearing. Run a pattern with the marking compound that comes in the install kit, measure the backlash, and measure the pinion drag. It should be really close if not perfect.

If it is close, you'll have to play with the shims slightly to get it right on. You'll kinda have to do this by feel.

When you get it dead on, disassemble everything again, take off the modified pinion bearing, then press the new bearings on and reassemble everything for the final time. Repeat for the rear axle.

West Coast Differential has a pretty good writeup on checking backlash and pinion drag and everything else. If you do a web search, you can find some pretty good guides. It isn't that hard, just takes time. And you have to be patient and very careful with your measurements.