Ring & pinion install. Crush sleeve & solid spacer help......

[wrd1972]

Hello, Im doing a 4.10 gear job on my Camaro. I was told that the solid spacer is extra insurance to avoid grenading the 4.10's.
I have purchased the spacer and have install questions.
The used and already crushed crush sleeve is .580".
The spacer is slightly less.
My question is how do you properly install this spacer.
Thanks all.

[Dan B. 96 T/A]

I've used the Ratech solid spacer, and it held up well with my Richmond 3.42's. The problem is the rearend. It's only a 7 3/4" ring gear and is too small for the HP that our cars are producing. You can also help it by using a t/a girdle cover and welding the axle tubes at the housing.

Honestly, just use the crush sleeve and save up for a 12 bolt or a 9 inch. I've been thru 5 gear sets for the stock rearend and it's a waste of time and money.

[Dan B. 96 T/A]

1. Install the new pinion bearing races in the housing. I use a seal/race tool made out of aluminum. A brass drift or steel plate will also work.

2. Lightly oil the races with 90 wt gear oil and install the pinion.

3. Holding the pinion in place against the race, install the yoke, washer, and original nut. Note: Do not use the new nut, seal, or crush sleeve at this time.

4. Tighten the nut until the bearings seat and removes end play. Using a dial in/lb. torque wrench with 0-30in/lb rating tighten the nut until there is 15-17 inch/lbs. of rotational drag on the bearings. This will preload them in the final position. A very slight tap with a brass hammer or drift against the pinion ends will help seat the bearings. Remember very light tap!

5. Install the carrier in the housing. Rotate the pinion by hand to be sure they move freely.

6. Using new shims add approximately the same size per side as the original cast shims were. Do not use the original cast shims. You may have to decrease the shim size to start.

7. The carrier should drop in with just a little resistance. It should be able to be removed by hand.

8. Install the bearing caps and torque to 60 ft/lbs. Do not use the bolts to draw down the caps, instead use a hammer to tap the caps in place then torque.

9. With the caps torqued check the backlash in the ring gear. Use a 1" dial indicator and magnetic base to check the backlash. Backlash ranges from .006-. 010" depending on the gear manufacturer. Refer to your note on the original backlash if reusing the gears. I set new Tom’s US Gears to between .007-. 009" and get a nice pattern.

10. If the backlash is not where it should be then you have to adjust the carrier shims in or out. If the backlash is too tight then the ring gear has to move away from the pinion. Remove .005 from the left shim and add .005 to the right shim as a starting point. If the backlash is too loose then the ring gear needs to go into the pinion.

11. Once the backlash is correct you need to see where the pinion is n relation to the ring gear center. Use marking paste, either white or yellow, and paint the teeth-both sides, in 2 places. Paint several teeth in each area.

12. Use a rag rolled up to act as a brake and load up the pinion gear while rotating it several revolutions in each direction. I use a 9/16" box wrench I made up. I took a 9/16-combo wrench and cut off the open-end side. I welded the wrench to a long piece of 5/8" Cold Roll Steel. Husky makes a nice double box wrench that works well too. A pattern will form in the marking grease. Look to see if the pattern is the same length in the base of the tooth and the top of the tooth. The convex side of the tooth is called the drive side, the concave side of the tooth is called the coast side. The end of the tooth near the center of the ring gear is called the Toe. The end of the tooth near the OD of the ring gear is called the Heel.

13. The pinion shim must be adjusted to get the pattern centered on the tooth, regardless of where the pattern is in relation to the toe or heel. Once the pattern is centered, see where the pattern is for the toe and heel. Ideally they should be both centered on the tooth but this is not always possible. If the drive side is centered or to the toe that’s ok. Under load it will spread out toward the heel. Performance setups are toward the Toe on the drive side. The coast side should be centered. With new gears and correct shim and backlash the pattern should be in this range. Refer to installation information that may come with the new gear set.

14. It will take several tries to get the pattern in range, so don’t give up.

15. Decreasing Backlash moves the Drive side Slightly lower and to the toe, the Coast moves lower and to the Toe.

16. Increasing Backlash moves the Drive side Slightly higher and to the Heel, the Coast moves higher and to the Heel.

17. Thicker Pinion shim with good Backlash moves the Drive side deeper and Slightly to the Toe. The coast moves deeper and more to the Heel.

18. Thinner Pinion shim with good Backlash moves the Drive side to the top and to the Heel. The Coast moves tot he top and Slightly to the Toe.

19. Once the pinion shim, backlash, and pattern are correct then disassemble again.

20. Install the new bearing if you have been using a setup slip fit bearing. Setup again to get the pattern right.

21. With the correct pattern and new bearing installed, disassemble,

22. This time the crush sleeve or solid pinion shim will be installed along with a new pinion seal and new nut.

23. Oil the pinion bearing with 90 wt gear oil, install the pinion in the housing, install the crush sleeve and outer bearing, pinion seal, yoke, washer and new nut. Use Loctite red on the nut. Torque the nut to get your setup rotational drag. The trick here is the crushing of the sleeve. It will take a BIG impact gun, Long breaker bar, or some other device to start the crush. I have used two methods that work. The first one is to place the housing with the pinion, in a press and press against the pinion until the bearings seat. Then just a little bit more. Remove the housing and check it with the dial torque wrench. Once the sleeve begins to crush the impact gun will drive it down. You don’t want to over crush the sleeve. If you over crush it then replace it with a new sleeve. The second method is to crush the sleeve in a press before installing it on the pinion. I measure the old sleeve to get a close reference point. Then install the sleeve in the press and use a plate against the OD. I press it until it starts to compress and begin the crush. I then install in on the pinion and use my impact gun to set it. Another method is to use a solid spacer and shims. This replaces crushing the sleeve, instead shims are used to set the length needed to preload the bearings and keep them from loosening up. I have not used the solid spacer yet but other have and report it is much faster and more accurate to set then the crush sleeve. The solid spacers can be made or purchased from Ratech in OH.

24. NOTE: The pinion seal Flange does not bottom out against the housing when installing. There should be a 1/8"(.125") gap between the housing and the seal flange. Use Permatex #2 sealant on the pinion splines to prevent oil leaking past the nut, I also put a little #2 on the seal OD Evenly tap the seal into the housing. A plate or wood block covering the seal OD will work to drive it in place. Place a little grease on the seal ID to prevent any dry damage when installing the pinion.

25. Install the carrier, only this time add .005 shim to each side to add a preload to the carrier bearings. You will have to hammer the shims in because of the increased thickness.

26. Install the bearing caps and at this time I swap out the hex head bolts for 7/16-14 socket head caps screws. They are a littler stronger. Some of the earlier differentials used a 5 line bolt marking that would not be a grade 8 bolt. The socket head cap screws are rated higher then grade 8 and work without any problem.

27. For HD applications a steel bearing cap and ½-13 bolts are used. This will require fitting of the cap and tapping the holes for the larger size bolts.

28. Install new Torrington BH2212 bearings in the side yoke bores, these are full needle bearings. Some of the kits I used came with bearings with half the needles in them. I trashed them.

29. Install new yoke seals. Some seals I’ve used are slightly larger OD and don’t easily fit the bore. The CR seals that NAPA sells work very well if you find you need seals or the ones in the kit are NG.

30. Grease the seal ID here too.

31. Install the side yokes. I don’t reuse side yokes. The originals were case hardened and ride up against the posi pin. The pin is harder and the yoke ends wear. Once the case hardening is gone they wear out quickly. It’s best to replace the yokes during a rebuild. The exchange yokes sold are rebuilt using hardened tips to prevent wear and offer a very long life span.

32. With the yokes n place install new snap rings in the groove on the end of the yoke. You will need 90* snap ring pliers to install the rings. If you rebuilt the posi like I do then the end of the yoke will be right on the pin or within a few thousands. I fit a .001-. 004" gap in between them for oil to slip in. If you followed the GM overhaul manual you may have more end play in the yokes because the clutches will not be shimmed as close as the springless method.

33. Add two bottles of GM posi additive and 90-wt-gear oil.

34. Use Permatex #2 on the rear cover gasket and install the rear cover. Torque the bolts to 50 ft/lbs. I use the HD Muskegon Brake rear covers. They have thicker mounting tabs to withstand more abuse then the stock cover can. Also, improper rear spring installation can break the stock cover mounting tab off or crack the cover.

Break In Procedure:

1. If using a new ring & pinion gear set, drive the car for 10-12 miles moderately. Stop and let the differential cool for 45-60 minutes. Do this several times.

2. Drain the oil at 500 miles. Use new GM limited-slip additive and 90-wt oil.

[Joe 1320]

Nice writeup.

I can vouch for the T/A girdle.... however..... the rear is still going to break if you decide to do high rpm clutch drops and you have traction. Mine has lasted with an automatic, but those can be a little less harsh to the rest of the driveline.

[Kevin - Blown 95 TA]

Hello, Im doing a 4.10 gear job on my Camaro. I was told that the solid spacer is extra insurance to avoid grenading the 4.10's.
I have purchased the spacer and have install questions.
The used and already crushed crush sleeve is .580".
The spacer is slightly less.
My question is how do you properly install this spacer.
Thanks all.

If I remember correctly, the spacer comes with with shims. You have to set the pinion depth with shims behind the big bearing as well as the rotating torque of the bearing preload with shims for the crush sleeve. You may have to assemble/dissassemble the rear end a couple times to get the spacing right which makes assembly harder than assembly with the crush sleeve which sets its own preload (works like a spring, but that's what's wrong with it). You have the choice of either pressing everything together & unpressing it apart, or you can go the route I took - I bought 2 identical pinion bearings ($12 for an extra) and opened the i.d. of one of them just slightly to use for fitment. Then, when everything was in spec, I did a final assembly using the other pinion bearing.

[wrd1972]

I will be setting my R&P pattern tonight.
Is it wise to just go ahead and have the drive side slightly to the toe to gain the maximum amount of strength, or just center the thing up.
Is it worth the effort? If so please descriibe how much it should be shifted. Obviously I want the strongest possible 10 bolt rear end.

Last question, I doubt I will ever put sticky slicks or drag tires on, I also rearely dump the clutch. Will this rear end go the distance under these conditions?

I usually refer to this:
http://www2.dana.com/pdf/5717.PDF

[Joe 1320]

While everything is apart, you might wish to have the housing straightened. That will help the longevity of the parts.

[wrd1972]

How exactly do you straighten the housing.

[Kevin - Blown 95 TA]

I will be setting my R&P pattern tonight.
Is it wise to just go ahead and have the drive side slightly to the toe to gain the maximum amount of strength, or just center the thing up.
Is it worth the effort? If so please descriibe how much it should be shifted. Obviously I want the strongest possible 10 bolt rear end.

That's what I did, but it makes slightly more noise that way. I can't tell you how much to go, but just slightly more than center pattern. That dinky pinion of yours is going to flex under load, you can count on it. You might consider aftermarket axles and maybe C-clip eliminators, but those are a hassle. the C-clips are a real weak spot in design as are the axles which serve as the inner race for the axle bearing.

Last question, I doubt I will ever put sticky slicks or drag tires on, I also rearely dump the clutch. Will this rear end go the distance under these conditions?

If you stay away from sticky tires, you will probably be OK. Weld the axle tubes, put on the support cover & studs, steel carrier caps, better axles, solid spacer. It's all more than half the cost of a good rear end to make it kind of strong. the problem is that not only is it weak, it's a bad design, but on the other hand, there are guys with 10 second cars which are still using the 10 bolt/7 1/2" rear.

[wrd1972]

Can you further describe what noise can be expected.

I think I will definitely shift the pattern some.
What are the other options for complete and stronger rear ends that will bolt up in our f-bodies. Do they have to be fabricated to mount the track bar and pan hard bar.

[Joe 1320]

How exactly do you straighten the housing.

While the entire housing is apart, the internal tubes are checked for straighness compared to the outer housing. The housing and axle tubes are straightened with a press to assure the axles are truely 90º to the ring and the outer tubes welded to the case.

[wrd1972]

I wonder why GM couldnt put a decent rearend in the f-bodies like Ford did for the mustangs. I remember those 8.8's were really strong and less prone to failure. Thaat was always a strong point for the stangs.

[Joe 1320]

I remember those 8.8's were really strong and less prone to failure. Thaat was always a strong point for the stangs.

That's because the rest of the driveline broke before the rear did.


It's not that bad of a rear end, but as people start dumping the clutch at high rpms with sticky tires, the rear is going to give. There are guys with automatics in the high tens with a stock rear without a problem. Autos tend to be a little easier on the rear. I just think the smaller case makes them noisy as heck compared to the older and larger casings. The issue of flex does come into play, axle tube straightening and additional bracing of the axle tubes to the center section cuts down on flex related failure. Same for using studs and a rear girdle. I think that's the real key to whether it lives or not under high power. That and cutting down the weight of the vehicle.