And Anti-spin Swap

With the replacement rear end OUT of the car: Unbolt the retainers on the ends of the housing. Get an axle puller (Auto Zone will loan one to you) and jerk out the axles. Clean those nasty axles, press off the old bearings and retainers and press on the new bearings and retainers. Then go put those axles in the corner. It will be a while before you need them. But first go try to stick them into the posi carrier you have to make sure the axle is the right diameter and has the correct number of splines.

Next remove the old axle seals and replace them with new ones. You will need a seal puller or a slide hammer with an attachment. The seals are pressed in the end of the axle housing. The best way to press them back in is to find a socket that is rhe right diameter and hammer them back into the axle tubes.

Next unbolt the cover plate and drain out all that old fluid. Next you have to pull out the old carrier. Clean off the caps that hold on the carrier with a good degreaser like alcohol. Then before removing the caps be sure to mark them as right and left or whatever. Be sure also to know which end is top and bottom. I used fingernail polish. Markings is necessary because these bastards are line bored after assembly. This is line bore thing is important to remember. Now take out that greasy carrier. You may have to pry it out. It also helps if you turn the pinion gear it will help lift the carrier out of the housing.

Now it is time to take out the pinion gear. The hardest thing will be getting the pinion nut off. I would soak it down with WD 40 or Liquid Wrench. Then get an impact wrench to get the pinion nut off. Of course you will have to find some way of keeping the pinion from turning. Once the nut is off, get a big hammer and smack the pinon gear. It will eventually come out of the housing. Do not screw up and smack the yoke.

You mihgt want to get a piece of wood and put it on the pinion and hit the wood instead of trying to hit the rear of the pinion while trying to miss the yoke. Once the pinion comes out, pry out the pinion seal. You can do this with a dull chisel or screw driver.

Next you will have to remove all of the old bearing races from the housing. There will be a notch in the housing at the rear of the race where you can get a punch in there to knock out the race. Actually there will be two notches. Now press the new bearing races into place. For this I found some really big sockets and an extension. I put the socket on the race and proceeded to hammer away. This was a major PITA for me because the rear end was still in the car. There are two bearing races in the carrier. The rear and front pinion bearings. Now get your new posi carrier and press the bearings onto the carrier. Go ahead and put your ring gear onthe posi carrier if it is not already on there. Be sure everything is clean. Be sure to put in the new pinion oil seal.

Now the fun begins. If you have a richmond gear there will be a check distance engraved on the face of the pinion gear and a backlash measurement engraved on the ring gear. These are CRITICAL numbers. If not you will have to use some general numbers. I think factory backlash is .005. My Richmond gear backlash was to be .008. If you have too much backlash you will know in a hurry. When you drive down the road and let up onthe accelerator you will get one loud whine.

The check distance is the distance from the centerline of the ring gear to the face of the pinion gear. This is one MF to measure. Technically you cannot do what you think is right. That is: lay a flat piece of metal across the face of the two caps and measure down to the face of the pinion. The reason this is not accurate is because the saddles are line bored. The caps are not exactly split in 1/2. Unless you have a pinion depth setter, you may just have to use the above method and hope for the best. However, if you do not have a check distance dimension you will just have to do it like this. I am going to ASSUME that you do not have a check distance dimension. In that case do the following:

If a shim came off of the pinon gear, put it back on the new pinion gear. Then press the rear pinion bearing up on the pinion shaft untill it is tight against the rear face of the pinion and shim. Then put the crush sleeve on then put the front pinion bearing on. The front pinion bearing is not pressed into place. It is held in place by the yoke. Then slide this mess back into the housing, put the yoke on and tighten it up slightly. You tighten up the yoke untillit takes about 15 INCH pounds to turn the pinion gear. OK assume this is done.

Now it is time to put the new posi carrier in place. Try to hold the races on the bearings and put it in the saddles. The ring gear should engage the pinion nicely. Now comes the trial and error BS. You put shim packs on each side of the carrier untill you get the proper backlash on the ring gear and the proper paint pattern. Once you THINK you are close, get some gear marking compound and apply it to the ring gear. Be sure to put your caps back on and torque them to about 65 FOOT pounds. Double check that torque I am doing this from memory. Once you have everything in place and painted up turn the pinion gear and see what pattern you get on gears. You are looking for a rectangular pattern that is even across the drive face of the ring gear. I am sure it will not be right the first time. Now you get to move shims from side to side untill the pattern is correct. Then check the backlash. I kinda did mime backwards. I got the backlash right and then checked the paint pattern. It turned out to be perfect when the backlash was correct. I also was able to measure my check distance before I ever put in the carrier. But I am assuming you can't.

Once you have the paint pattern anb backlash correct, you are good to go. Put everything back together and drive off. And listen. If you have strange noises. TRY AGAIN. Be sure to use a good lube and put the limited slip additive in there or you will get chatter and grabbing and such. Do not use synthetic gear lube!

The most critical part in all of this is getting the correct gear teeth mesh. Take your time with those shim packs. Of course if you have crappy luck like me and your pinion depth is wrong, you will be screwed. You will have to take the pinion gear back out and put in the right shim to adjust the depth of the pinion in and out.

[ Thanks to John Harris for this information ]

Clutch Plate Anti-Spin

I can see no reason why a rebuilt clutch plate type posi can't be rebuilt good as new. This assumes no obvious mechanical failures which would otherwise render the unit useless. It is/was common practice among drag racers to take a brand new unit and tighten it up as much as possible by using thicker plates and other means. If the car is street driven, you must use gear lube formulated for posi units.

[ Thanks to Bob Handren for this information ]

Cone Plate Anti-Spin

It is also a cone type posi unit. If that is shot it cannot be rebuilt in the same fashion as the plate/friction type. They can however be made functional with a little work.

[ Thanks to Bob Handren for this information ]