It's not that difficult. I could walk you through it. Setting the pinion depth is the trickiest part and as long as you have a good pair of calipers or veneers and access to a press you'll be fine.

This is what you'll do.

Disassemble the differential. Remove the diff cover. Loosen the 8mm bolt that holds the differential shaft in place. Remove the differential shaft. Push in both side axles. (the brake assembly from both sides needs to be removed, calipers, rotors, etc. prior to performing this). Now you can remove the axle retaining C-clips. Once these are removed you can slide the axles out of the differential. You next loosen all 4 carrier main cap bolts. Mark the carrier main bearing caps (Right and left side as well as the top of the cap) I usually mark the left side top with one dot from a punch, and the right side top with two dots from a punch) You'll also mark the right and left carrier shim.

Next you'll loosen the pinion nut. You'll need a bar to hold the pinion flange. I typically go to lowes and purchase a 3 foot long piece of bar stock and drill it out and machine one side so that you can bolt it directly to the pinion flange with two of the pinion flange bolts. I'll take a pic of the one I use for our differentials. And after reading this, I would be more than glad to mail out the one I use if you like as long as you mail it back At any rate. This is the hardest part of the job. I typically allow the bar, once bolted to the flange, to rotate around and rest up against the exhaust or underside of the car as you begin to loosen the pinion nut. Once you loosen the pinion nut, you can remove it as this gets discarded. The ring and pinion set will come with a new pinion nut. You can now remove the pinion gear. The easiest way to set pinion depth is to remove the pinion bearing from the old pinion. You'll need a press to perform this operation. Once the pinion bearing is removed you will do two things. You'll measure the old pinion bearing shim thickness and write it down. As an example assume the shim thickness is .022 inches. Next you will measure the thickness of the pinion gear from the face of the gear to the bearing landing. The bearing landing is the flat machined part of the pinion that the pinion shim rests against. As an example lets assume the thickness or height of the gear from the gear face to the bearing landing is 2.10 inches. You will now add 2.10 + .022 and you get 2.122 inches. This is now your targeted pinion gear height from face to bearing landing plus shim. Next measure the thickness or height of the new pinion gear from its face to the bearing landing. Let's assume for this example that it is 2.08 inches. You will then want to use a shim that is .024 inches. so that the total thickness is 2.122 inches. The gear kit will come with a shim pack. Select a .024 inch shim place it on the pinion gear and press on your new bearing. That's it. Your pinion depth will be spot on. The rest is gravy.

Now I will say if your differential has significant mileage on it I would recommend replacing the pinion and carrier bearings as well as the bearing races. If you need help with this I can explain this process too.

Next you will want to reinstall the new pinion gear. You will slide the new crush sleeve onto the pinion gear and insert it into the differential housing. Then slide the pinion flange onto the pinion gear spline and thread on the new pinion nut. The pinion flange should still have on the piece of modified bar stock. Now you will need a real good 1/2 inch drive breaker bar with a pipe for leverage or a 3/4 inch drive set and a pipe for leverage to begin tightening the pinion nut. You'll begin the arduous process of crushing the crush sleeve and setting the pinion preload. You'll also need an inch pounds torque wrench to measure the preload. Ok this isn't tough at all. As you tighten the pinion nut you don't need to pay too much attention at first. But be mindful as the crush sleeve gets crushed the bearings will begin to make contact with the bearing race surfaces. This is when you'll want to begin making 1/8 turns of the breaker bar and checking pinion preload between 1/8 turns. The preload will climb quickly. If you are using new bearings and races I like a tighter pre-load of about 24-26 inch pounds as the pre-load will loosen as the new bearings seat in.. If you're using old bearings, etc. I like to target 18 inch pounds. Keep making the 1/8 inch turns and checking pre-load with your inch pounds wrench in between turns. Once your inch pounds wrench is indicating the correct pre-load, stop. You're all done with the pinion. There is nothing more to do. You've verified pinion depth and that doesn't change once you have it set. and now your pre-load is set. Next you'll move onto the carrier and ring gear.

You'll need to remove the old ring gear from the carrier. Just unbolt all bolts, and use a nice dead blow rubber capped hammer to knock off the old ring gear. Re-install the new ring gear by lining up the bolt holes and with the same rubber hammer gents tap the ring gear in place rotating the carrier and ring gear so that the ring gear goes on evenly. Then thread all bolts by hand. (The kit comes with new ring get bolts too). Then torque down the ring gear bolts to appropriate torque spec. You can now re-install the carrier/ring gear assembly. Ideally you should use a case spreader but I have found this isn't necessary. Carefully slide the carrier bearing races into place and use the factory carrier shims that you removed and put the shims back in their respective places (right shim to right side and left shim to left side, etc.) You can begin to wiggle this assembly back in place. Be patient. This takes a little finesse but you'll get the hang of it. Once it's real close and looks like it just needs a little persuasion to go into place feel free to take a rubber hammer and tap the carrier races and shims a little. Once you are real close. You can try bolting the carrier main caps into place by hand. If you can hand thread these, you'll be able to get the carrier into place the rest of the way by torquing down the carrier caps. Do this evenly. meaning tighten the right side cap a few turns, then move to the left. Torque down the caps and check your backlash with a dial indicator. mount the dial indicator to the face of the axle assembly that the differential cover bolts to and rest the dial needle against the outside leading edge of one of the teeth on the ring gear. Gently rotate the ring gear back and forth, stopping just as it makes contact with the pinion gear. This is your backlash. I usually shoot for about .009 inches. The range is .008 to .015. Now most times this is right within spec. I mean almost dead on. If for some reason it isn't you will need to change the thickness of the carrier shims. so let's say you had more than .015 inches of backlash. Let's say you had .018. Then your ring gear was too far away form the pinion gear and you would want to take away shim from the left side of the carrier and add that exact amount of shim to the right side. Meaning if you made the left side shim .002 inches thinner, you will want to make the right side shim .002 inches thicker. Then reassemble and check backlash again.

The backlash is not linear either. Meaning if you are .005 inches of backlash too loose you won't want to move the carrier .005 inches toward the pinion gear. I would start with a carrier shim change of .002 inches in that example.

I hope I didn't make this sound too complicated because it isn't. If I have any typos, please let me know. and feel free to hit me up via private message anytime and we can swap phone numbers and we can chat further, etc.

 

Yeah that doesn't seem too bad. The only issue I think I'll have is the press...I've got one at work but I'd have to get a ride in considering my rear end will be torn apart when I need to use it...

 

Yeah that is the pia part. You can always hit harbor freight up and use your ring and pinion gear swap as an excuse to buy a press. Their 12 ton press for $169 will do the job nicely. You'll also need to purchase a bearing separator for about $30 as well. I stand corrected. You can buy their 20 ton press for $155.