GK
07-21-2005, 08:49 PM
1. When you pull the differential out, make sure that the bearing, race, and shim on the right side, goes back in the right side when you reinstall, and the same thing for the left. If you mix it up, you've just set yourself up for a rear-end that the tolerances are messed up on.
2. If you remove the nut that holds the pinion assembly in (this nut is the one that also holds the yoke for the drive shaft), you need to use a new crush sleeve on reassembly, even if you do not change anything else.
You can take the differential out, and then can spin the pinion by itself and feel the bearings without removing it. So if you are just pulling it apart to see what is wrong, you can save 2 hours by not removing it. If you remove the pinion, after removing the nut and pulling off the yoke, it will come right out.
3. Then, to replace the bearings, the old bearings need to be pressed off, and the new bearings pressed on. If you don’t have access to a press, take it to a machine shop, then can do it in a couple of minutes,
4. Removing and reinstalling the pinion bearing races. You need to punch out the old bearing races, and punch new ones in. The old ones should come out with a few good whacks, the front one you punch out from the rear of the differential, the back one from the front. They give you space to hit it from the opposite sides.
Installing the new races can be tough. You need to knock them in with the brass punch, and you need to make sure that they are fully seated in as far back as they will go. If they aren't, your gears will be way off.
When you are sure that they are in all the way, to where the back of the race is right up against the lip in the case, you get to go to step 5.
5. Reinstalling the pinion. By now you should have your new bearings on. You will want to insert the pinion through the back, and slide on the crush sleeve, the factory shim that you took off, the yoke, and then the nut from the front.
Now comes the extra fun part of crushing the crush sleeve. You will want to tighten the nut until it is snug, and then bust out your impact wrench. DO NOT TRY THIS WITH A NORMAL SOCKET WRENCH.
What you need to be doing is "buzzing" the impact wrench against the nut in short bursts, then spinning the nut with an inch lbs torque wrench, as more preload is exerted on the inner bearing, it will take more torque to spin the nut. There is a specific value of torque needed to spin it, that when you reach it, you are there.
If you over crush it, you must take it apart and try again with a new crush sleeve, so go in short bursts with the impact wrench. Once you have it together, you get to move on to reinstalling the differential.
6. This is easiest with two people. One person to guide the differential into place, the other to keep the races and shims together. You will want to place the race back over the bearing on the differential on the right and left sides. On the right side, also hold the shim in place against the bearing with the tapered end out. Leave the left side shim out for now.
Place the differential up in the carrier, and hold it and the right side race and shim in the proper location. Then, push the left side shim in as far as you can. It will not go all the way, you will need to tap it in with a rubber mallet preferably, but you can use a hammer. Just be gentle.
When it all the way in, the tapered edge (facing out, remember) will seat into the rear-end case. The shims and races should be at an even depth with one another, and the differential should be holding itself in. Now, you will want to bolt the caps back in. The caps are the iron half circles that held the differential in place. The notch on the caps face outward on each side. It is important that the cap that was on the right when you took it apart also stays on the right, and vice versa. Tighten them down to 80 ft lbs.
7. This is the moment of truth, where you get to see if it will be an easy job or a PITA. You now have the ring and pinion assembly totally together. Now you need to check it and see if the tolerances are right. If you got the races pounded in right, you shouldn't. The primary concern is backlash.
Backlash means just that, back of lash. Lash is defined as the point in which there is zero room between the two gears (think zero lash on your valve train is the point where there is no play in the valve train). You want a little but of clearance, hence back of lash. The correct spec IIRC is .005-.008 of backlash. You need to measure this with a dial gauge.
You measure it by holding the ring gear in place, and seeing how much the yoke moves when rotating it back and forth. .005-.008 lash is so tiny that by hand you can barely feel it, just the tiniest bit of play. If you want to feel it beforehand to get a ROUGH idea of what it feels like, do this same test on the rear before you disassemble it.
There are lots of people who claim that they don't need a gauge to measure, that they can "feel" the amount of backlash. I've been able to tell when it is close, but let’s be honest. You aren't going to be able to tell the difference between .005 and .015, but one will make noise and the other won't. That’s one measurement.
The other measurement is the amount of torque needed to turn the assembly. Simply put your inch lbs torque wrench back on the pinion nut, and spin it, thus spinning the pinion and ring gear. This is another specification that I don't remember off-hand.
I'm leaving out the gear interface pattern. This is a visual inspection of where the ring and pinion gear mesh with each other. I'm leaving this out because with the stock gears, provided the backlash and pinion depth are right, this will be right too. So, if you have the backlash right, the pinion depth right, and the force to turn right, congratulations. Your rear-end should not make any noise on the road.
8. The rest is the simple parts. After getting that set up, you want to reinstall the axles. Simply push them in, rotating them until the splines match up with the differential, and then they will slide in. Do one at a time. Push one in as far as it will go. Then, you need to reach into the open space in the differential with the C clip. The c clip is just that, a little pac man looking metal piece. It will fit into a groove in the axle. Push it in, then pull the axle back out to hold the clip in place. Do the same with the other side.
Now, you need to reinstall the drift pin. It is a circular rod that you removed to get the axles out in the first place. Slide it in place. It has a hole on one end, where a little bolt threads in. This bolt holds the drift pin in place, which holds your axles in, which keep your wheels on. This bolt should get some lock tite on it before it gets installed. If that little bolt works its way out, the drift pin will fall out, then the c clips will fall out, then your axles will fall out.
9. Guess what? You are done. Now all you need to do it reconnect the drive shaft, put the drums back on, put the tires back on, and reseal the rear cover. Refill with oil and limited slip additive, and go!
It’s recommended that you keep speeds down on new bearings for about a hundred miles to keep from cooking them while they break in, so keep it under 55.
2. If you remove the nut that holds the pinion assembly in (this nut is the one that also holds the yoke for the drive shaft), you need to use a new crush sleeve on reassembly, even if you do not change anything else.
You can take the differential out, and then can spin the pinion by itself and feel the bearings without removing it. So if you are just pulling it apart to see what is wrong, you can save 2 hours by not removing it. If you remove the pinion, after removing the nut and pulling off the yoke, it will come right out.
3. Then, to replace the bearings, the old bearings need to be pressed off, and the new bearings pressed on. If you don’t have access to a press, take it to a machine shop, then can do it in a couple of minutes,
4. Removing and reinstalling the pinion bearing races. You need to punch out the old bearing races, and punch new ones in. The old ones should come out with a few good whacks, the front one you punch out from the rear of the differential, the back one from the front. They give you space to hit it from the opposite sides.
Installing the new races can be tough. You need to knock them in with the brass punch, and you need to make sure that they are fully seated in as far back as they will go. If they aren't, your gears will be way off.
When you are sure that they are in all the way, to where the back of the race is right up against the lip in the case, you get to go to step 5.
5. Reinstalling the pinion. By now you should have your new bearings on. You will want to insert the pinion through the back, and slide on the crush sleeve, the factory shim that you took off, the yoke, and then the nut from the front.
Now comes the extra fun part of crushing the crush sleeve. You will want to tighten the nut until it is snug, and then bust out your impact wrench. DO NOT TRY THIS WITH A NORMAL SOCKET WRENCH.
What you need to be doing is "buzzing" the impact wrench against the nut in short bursts, then spinning the nut with an inch lbs torque wrench, as more preload is exerted on the inner bearing, it will take more torque to spin the nut. There is a specific value of torque needed to spin it, that when you reach it, you are there.
If you over crush it, you must take it apart and try again with a new crush sleeve, so go in short bursts with the impact wrench. Once you have it together, you get to move on to reinstalling the differential.
6. This is easiest with two people. One person to guide the differential into place, the other to keep the races and shims together. You will want to place the race back over the bearing on the differential on the right and left sides. On the right side, also hold the shim in place against the bearing with the tapered end out. Leave the left side shim out for now.
Place the differential up in the carrier, and hold it and the right side race and shim in the proper location. Then, push the left side shim in as far as you can. It will not go all the way, you will need to tap it in with a rubber mallet preferably, but you can use a hammer. Just be gentle.
When it all the way in, the tapered edge (facing out, remember) will seat into the rear-end case. The shims and races should be at an even depth with one another, and the differential should be holding itself in. Now, you will want to bolt the caps back in. The caps are the iron half circles that held the differential in place. The notch on the caps face outward on each side. It is important that the cap that was on the right when you took it apart also stays on the right, and vice versa. Tighten them down to 80 ft lbs.
7. This is the moment of truth, where you get to see if it will be an easy job or a PITA. You now have the ring and pinion assembly totally together. Now you need to check it and see if the tolerances are right. If you got the races pounded in right, you shouldn't. The primary concern is backlash.
Backlash means just that, back of lash. Lash is defined as the point in which there is zero room between the two gears (think zero lash on your valve train is the point where there is no play in the valve train). You want a little but of clearance, hence back of lash. The correct spec IIRC is .005-.008 of backlash. You need to measure this with a dial gauge.
You measure it by holding the ring gear in place, and seeing how much the yoke moves when rotating it back and forth. .005-.008 lash is so tiny that by hand you can barely feel it, just the tiniest bit of play. If you want to feel it beforehand to get a ROUGH idea of what it feels like, do this same test on the rear before you disassemble it.
There are lots of people who claim that they don't need a gauge to measure, that they can "feel" the amount of backlash. I've been able to tell when it is close, but let’s be honest. You aren't going to be able to tell the difference between .005 and .015, but one will make noise and the other won't. That’s one measurement.
The other measurement is the amount of torque needed to turn the assembly. Simply put your inch lbs torque wrench back on the pinion nut, and spin it, thus spinning the pinion and ring gear. This is another specification that I don't remember off-hand.
I'm leaving out the gear interface pattern. This is a visual inspection of where the ring and pinion gear mesh with each other. I'm leaving this out because with the stock gears, provided the backlash and pinion depth are right, this will be right too. So, if you have the backlash right, the pinion depth right, and the force to turn right, congratulations. Your rear-end should not make any noise on the road.
8. The rest is the simple parts. After getting that set up, you want to reinstall the axles. Simply push them in, rotating them until the splines match up with the differential, and then they will slide in. Do one at a time. Push one in as far as it will go. Then, you need to reach into the open space in the differential with the C clip. The c clip is just that, a little pac man looking metal piece. It will fit into a groove in the axle. Push it in, then pull the axle back out to hold the clip in place. Do the same with the other side.
Now, you need to reinstall the drift pin. It is a circular rod that you removed to get the axles out in the first place. Slide it in place. It has a hole on one end, where a little bolt threads in. This bolt holds the drift pin in place, which holds your axles in, which keep your wheels on. This bolt should get some lock tite on it before it gets installed. If that little bolt works its way out, the drift pin will fall out, then the c clips will fall out, then your axles will fall out.
9. Guess what? You are done. Now all you need to do it reconnect the drive shaft, put the drums back on, put the tires back on, and reseal the rear cover. Refill with oil and limited slip additive, and go!
It’s recommended that you keep speeds down on new bearings for about a hundred miles to keep from cooking them while they break in, so keep it under 55.