Rear Wheel Bearing Assembly

[Glenn B.]

I started a "rebuild my brake system" project which has now grown into a wholesale restoration of the rear suspension. The rear splash shields were in rough shape, and to replace them requires removal of the rear spindle which pretty much requires removal of the trailing arm. After wrestling the trailing arm out, I went to remove the spindle, what I found on removal seems unusual.

The spindle bearings had the normal spacer and shim between the inner and outer bearings. Strangely - I found another shim between the inner bearing and the spindle flange. Prior to removal - there was very little play, but if I were to reassemble with only the original spacer and shim, I would have at least .050 of play. I am thinking that the added shim between the bearing and flange was someones innovative idea of a "shortcut method" (to not have to fit the correct size internal shim) and yet only seat the bearings once. It seems to me that the inner bearing would not be seated properly this way - but maybe this is no big deal for practical purposes.

Is this something that is commonly done?

[Joe L.]

Re: Rear Wheel Bearing Assembly

I started a "rebuild my brake system" project which has now grown into a wholesale restoration of the rear suspension. The rear splash shields were in rough shape, and to replace them requires removal of the rear spindle which pretty much requires removal of the trailing arm. After wrestling the trailing arm out, I went to remove the spindle, what I found on removal seems unusual.

The spindle bearings had the normal spacer and shim between the inner and outer bearings. Strangely - I found another shim between the inner bearing and the spindle flange. Prior to removal - there was very little play, but if I were to reassemble with only the original spacer and shim, I would have at least .050 of play. I am thinking that the added shim between the bearing and flange was someones innovative idea of a "shortcut method" (to not have to fit the correct size internal shim) and yet only seat the bearings once. It seems to me that the inner bearing would not be seated properly this way - but maybe this is no big deal for practical purposes.

Is this something that is commonly done?

Glenn------


It is definitely NOT commonly done. In fact, I've never seen or heard of this before.

[Steve G.]

Re: Rear Wheel Bearing Assembly

I think something slipped out of place as you took it apart and you didn't notice it. That additional shim had to be between the two bearings to affect end play. Adding shims outside either bearing could not possibly affect end play. Putting a shim between the inner bearing inner race and the flange will only serve to move the flange inboard, which will not vary the end play at all.
Steve

[Gary R.]

Re: Rear Wheel Bearing Assembly

I have seen a 030" shim on the inner bearing surface on 82 arms . I have never seen it on the earlier years. I have seen and continue to see plenty of "hack" work done on arms so it is possible someone did this. The face of the spindle flange gets beat-up pretty bad, often the stamped numbers off the original bearings are transferred to the flange face. Possibly someone filed the end? I dress them on a surface grinder but 050 endplay is way out spec, there are other issues there. The bearing races are seated in the support bores. The endplay is established by using the correct size shim in between the bearing cone races. The bell spacer is another part that gets distorted and should be dressed on a SG. The shims sold in the common kits are too wide in range to really dial in the endplay without any lateral play. There are different methods on all these forums for setting up rear bearings, some include "seating" the bearings. However I have never seen any change using the seating method, grinding the parts flat and to size is the way to set them up.

[Glenn B.]

Re: Rear Wheel Bearing Assembly

Steve, as strange as it may seem, the second shim was definitely between the outside of the inner bearing and the flange. I scratched my head on this and tried to convince myself that it must have been set up as you suggest - but the second shim and the flange surfaces have mirror image letter markings that have transferred from one piece to the other. With just the single shim in place (between the bearings) - I have significant end play and need to reduce the size of the single shim.

Gary, yes - I've found a few good articles online regarding setting up the shims correctly. I have ordered a new shim kit and can carefully grind one down as needed.

I have been very fortunate with my car that restoration work done before I arrived was mainly done properly - but it seems Bubba has also managed to leave the odd mark here and there...

[Steve G.]

Re: Rear Wheel Bearing Assembly

I have seen a 030" shim on the inner bearing surface on 82 arms . I have never seen it on the earlier years. I have seen and continue to see plenty of "hack" work done on arms so it is possible someone did this. The face of the spindle flange gets beat-up pretty bad, often the stamped numbers off the original bearings are transferred to the flange face. Possibly someone filed the end? I dress them on a surface grinder but 050 endplay is way out spec, there are other issues there. The bearing races are seated in the support bores. The endplay is established by using the correct size shim in between the bearing cone races. The bell spacer is another part that gets distorted and should be dressed on a SG. The shims sold in the common kits are too wide in range to really dial in the endplay without any lateral play. There are different methods on all these forums for setting up rear bearings, some include "seating" the bearings. However I have never seen any change using the seating method, grinding the parts flat and to size is the way to set them up.

Transfer of the imprint from the race to the adjacent part is normal and not an indication of anything being beaten up. It happens when the parts are properly tightened together. I see it all the time on bearing setups of all kinds.
I would be reluctant to dress the flange or the spacer on a surface grander. In the case of the flange, very hard to ensure you are keeping the end perfectly perpendicular to the center line. If the spacer is distorted, throw it away. Keeping the ends perfectly parallel is critical and again very difficult to do with a surface grander. If either of those parts are not square to the shaft and each other when the bearings are tightened together you are loading one side. Bearings will not wear properly.

The only logical reason I can see for shims outside the bearing setup would be to move the seal contact area on the flange (or the shaft if the shim is between the outer bearing and the spindle) in the event the seal has worn a groove in either. An alternative to a redi-sleeve.


I would inspect the parts and replace as required, ignoring the out of order shim.

[Gary R.]

Re: Rear Wheel Bearing Assembly

Transfer of the imprint from the race to the adjacent part is normal and not an indication of anything being beaten up. It happens when the parts are properly tightened together. I see it all the time on bearing setups of all kinds.
I would be reluctant to dress the flange or the spacer on a surface grander. In the case of the flange, very hard to ensure you are keeping the end perfectly perpendicular to the center line. If the spacer is distorted, throw it away. Keeping the ends perfectly parallel is critical and again very difficult to do with a surface grander. If either of those parts are not square to the shaft and each other when the bearings are tightened together you are loading one side. Bearings will not wear properly.

The only logical reason I can see for shims outside the bearing setup would be to move the seal contact area on the flange (or the shaft if the shim is between the outer bearing and the spindle) in the event the seal has worn a groove in either. An alternative to a redi-sleeve.


I would inspect the parts and replace as required, ignoring the out of order shim.

Hi Steve
I agree the imprint transfers is a normal occurrence in this type of setup however I have measured the flange faces out as much as 005". I have dressed hundreds of them on a surface grinder flat and parallel without any issue. About the only ones I couldn't save were ones with a rolled edge and lip. It would require removing more material then I would like. Those are very rare indeed though.

The shims and bell spacers are also not flat when disassembled. Most are clear to the eye. The stock bell spacers inner angle is the only real reason to toss one away. They certainly can be parallel ground, again done them for years, however they need to be checked on a setup fixture to be sure they will not hang up on the shoulder of the large diameter. After grinding this is checked and if the setup tightens correctly they are fine. If they do not then I toss them and use a new spacer. The new spacers are counterbored and this is not a problem. One of the few aftermarket parts that are better then the originals. I still kiss grind them parallel though.

I use the same process setting up differential solid pinion sleeves used in HP applications in place of stock crush sleeves.

I say this not to cause an argument, like I mentioned there are plenty of methods online, it is what has worked for me for street cars. Interestingly when building street/strip vette arms with larger bearings and axles I go into a preload setup.

Glenn as long as your mating parts are smooth parallel surfaces you should be fine with the new shim kit. Just measure them at 90* points, I have found new shims out too.

Good luck, call me if I can offer any advice.

[Steve G.]

Re: Rear Wheel Bearing Assembly

Hi Steve
I agree the imprint transfers is a normal occurrence in this type of setup however I have measured the flange faces out as much as 005". I have dressed hundreds of them on a surface grinder flat and parallel without any issue. About the only ones I couldn't save were ones with a rolled edge and lip. It would require removing more material then I would like. Those are very rare indeed though.

The shims and bell spacers are also not flat when disassembled. Most are clear to the eye. The stock bell spacers inner angle is the only real reason to toss one away. They certainly can be parallel ground, again done them for years, however they need to be checked on a setup fixture to be sure they will not hang up on the shoulder of the large diameter. After grinding this is checked and if the setup tightens correctly they are fine. If they do not then I toss them and use a new spacer. The new spacers are counterbored and this is not a problem. One of the few aftermarket parts that are better then the originals. I still kiss grind them parallel though.

I use the same process setting up differential solid pinion sleeves used in HP applications in place of stock crush sleeves.

I say this not to cause an argument, like I mentioned there are plenty of methods online, it is what has worked for me for street cars. Interestingly when building street/strip vette arms with larger bearings and axles I go into a preload setup.

Glenn as long as your mating parts are smooth parallel surfaces you should be fine with the new shim kit. Just measure them at 90* points, I have found new shims out too.

Good luck, call me if I can offer any advice.

Hey Gary,

No intent to cause an argument either. I find the best information usually to be the result of discussion and sharing information.

To that end, how do you mount the flange in a surface grinder to ensure that the shaft centre line is perpendicular to the grinder surface? Given the shape and construction of the flange I find that a mill or a lathe is the best way to ensure the end is square. Even if you have developed a method to hold it square in a grinder, how do you check it afterwards? You would still need to mount it on some kind of rotating fixture, like a lathe, zero it on the seal surface then check end runout. Wouldn't it be just as easy to do the whole job on the lathe?

I don't doubt for a moment that you can save a spacer, but why would you, given their cost? Out of all the ones I've done since the 70's I have seldom seen where the inner races have turned and damaged the spacer. If they haven't turned against the race, they are in the same shape as they were when they went in. There really isn't another way for them to distort.


What's the advantage of a solid pinion spacer over a crush sleeve. The nature of the way they install with the crush ensures that the load is equal all around the race, eliminating any concern for off square shims or spacers. And, assembly is quicker. Once they are in a preload condition the spacer will not crush any further with load. What is the advantage I'm missing?

Steve

[Gary R.]

Re: Rear Wheel Bearing Assembly

Hey Gary,

No intent to cause an argument either. I find the best information usually to be the result of discussion and sharing information.

To that end, how do you mount the flange in a surface grinder to ensure that the shaft centre line is perpendicular to the grinder surface? Given the shape and construction of the flange I find that a mill or a lathe is the best way to ensure the end is square. Even if you have developed a method to hold it square in a grinder, how do you check it afterwards? You would still need to mount it on some kind of rotating fixture, like a lathe, zero it on the seal surface then check end runout. Wouldn't it be just as easy to do the whole job on the lathe?

I don't doubt for a moment that you can save a spacer, but why would you, given their cost? Out of all the ones I've done since the 70's I have seldom seen where the inner races have turned and damaged the spacer. If they haven't turned against the race, they are in the same shape as they were when they went in. There really isn't another way for them to distort.


What's the advantage of a solid pinion spacer over a crush sleeve. The nature of the way they install with the crush ensures that the load is equal all around the race, eliminating any concern for off square shims or spacers. And, assembly is quicker. Once they are in a preload condition the spacer will not crush any further with load. What is the advantage I'm missing?

Steve

Hi Steve
Yes it can be done in a lathe. In fact I first set it up in a lathe on a splined shaft to hold it. I check the large face for runout, many times this face is not out. Once I know that face is flat and perpendicular to the center line I could at that point kiss face it. I like the grinder better though for this application. Using the flat face on a granite plate I check the small end with an indicator. I mount it in the grinder and grind the small face, flip and kiss the large. I have a rotating grinding fixture I could use but I never had the need to. I use the same shaft to polish the seal OD smooth. That is how I do them, never had a bearing failure and although endplay is the spec most refer to I set them up for -0- lateral play which results in -.0015" endplay. Just a note too on endplay, it is very subjective to the person doing the job. I played around with making a fixed load tool for these bearings but they are not like machine tool bearings and they work fine within that window. I also dial them in with my fixture in a vertical position as I found it gave me more precise readings then a horizontal one.

As for the bell spacer, true they run about $15 each for a new one but I like to reuse parts if still good. I have a box of worn ones here I use for seminars or to show guys when they stop in. The worse one I found was out 005" this does not count the ones previous people worked on, those are usually in poor shape or even burnt by a torch. It doesn't take me long to parallel grind the spacers and check them on my fixture. Once I snug up the bearings with the shim and spacer a 001 feeler should not slide under the bearing. With a spacer hanging up on the spindle shoulder it will easily.

Differential solid sleeves have been around since Moses I think. There are now adjustable ones but I have not tried those. For most street cars the stock sleeve is fine. For cars that will launch hard the stock sleeve could compress just as if you over tighten the pinion yoke setting one up. Rock climbers have similar concerns. Unlike the stock sleeve the solid will not compress and is setup differently. It is torqued to 125 ft/lb then the drag is checked. The kits are made by Ratech so you can check them out online. They come with thin shims so in theory you can change the shims to set the drag to the 17-19 where I dial them in. In reality they are no where close enough so I grind the sleeve, approx. 005" = about 5-7 in/lb drag so this is a job I do in the grinder over a lathe as well.
While speaking of HP mods another one is to replace the LH stock cap with a steel one. These are sold by Tom's and Mark Williams and have to be machine fit as well. I show all these mods on digitialcorvettes if you want to see them. I could repost them here but some may object.

As I said these are the things that work for me and have run through some hard abusive cars. My son's last trip to the track resulted in shearing the inner/outer Spicer solid 1350 with one dead hook. I built him a 1480 12 bolt IRS now and all the mods I speak of have been run in at the track in this car. The most power so far put to one was from a 72 with a 950hp BB and TH400.

[Steve G.]

Re: Rear Wheel Bearing Assembly

I like to rely on the lab condition research the engineers did to arrive at the best possible setup clearance. It's not just load, in fact it's very little about load. It's more to do with thermal expansions. The oe engineers are better qualified and have better facilities to determine this than I do, so I opt to go with the tight end of their spec.

I guess whatever works for you is what you do, but I couldn't afford to go the route you do with the flange and the spacer. Too much repetition in the process with the flange. At a buck and a half a minute for my shop time, I have to make the best use of it. The $15 the spacer is worth only buys 10 mins. That's not much time to measure, setup, cut and re-measure, never mind the tool wear.

I do diffs of all kinds and there are numerous styles of adjustment for carrier and pinions. Different manufacturers have different methods, all do the job they were intended to do, but some are easier to work with in the field. Arguably one of the best diffs out there is the Ford 9". Coincidentally, it is the easiest to set up in the field. Threaded carrier adjustments and a removeable pinion carrier. Another very popular hd diff is the Dana 60, arguably the worst to set up with the carrier adjusted with shims under the pressed on carrier brgs. Totally different adjustment styles but both equally stout diffs.

The point is, they all work equally well although adjusted differently. Likewise with the preload crush sleeves vs shims. I disagree strongly with the supposition that the crush sleeve will compress under heavy launch. It defies logic. In the forward rotation the pinion is pushing forward, the load going from pinion head, to inner race to rollers to outer race, to housing. There is no load on the crush sleeve. In reverse, the load is pinion head/shaft to nut, to frt brg inner race, to rollers to outer race to housing. Still no load on the sleeve.

In fact, the only thing the crush sleeve and the preload shims do is allow the pinion nut to be tightened enough that it won't back off. In the trade you would see guys that replaced pinion seals without replacing the crush sleeves. They would tighten the nut to get the right preload on the bearings, but it would take very little torque to get it there. Worked ok, but eventually the nut comes loose, even with a new locknut. Takes over 300 ft lbs to crush the sleeve. That's making that nut pretty tight!

But as you say, there are different ways to do things. Some are about saving time and money, some developed because that's the equipment you have. It's not always easy to determine if one method was better than another because it may mean going 60,000 miles instead of 50,000, something that's very difficult to track. So unless I've seen some pretty convincing arguments I like to follow the oe specs and methodology as close as I can.

Each to his own, but the discussions are always interesting and gives those that might want to do their own work something to ponder.
Steve

[Gary R.]

Re: Rear Wheel Bearing Assembly

Very good points Steve.

I guess there will always be the argument on which is stronger, the 9" or 12 bolt both have their place and I'm sure you have seen both fail as well. I guess it depends how much of a chevy or Ford guy it is doing the talking. I've heard for the past 45 years since I was a kid. I'm not crazy about the Dana's, at least the 80-82 corvette ones, and don't take them in. The Dana 60 converted to a vette IRS are pretty much the strongest IRS setup out there but try and find one. The last one saw had a spool and was $5500 used. I think the 1480 12 we have will hold up fine. My 72 has a blueprinted 10 bolt and it is all I need to going out driving on a nice day.

I understand you have to weight your time vs the repair, time is money when you're in the trade. I'm not governed by time and will put as much time as it takes to get it where I want it. Money is not my motivation. I probably put more time into polishing and tuning a posi then rebuilders do for the whole job but that's ok with me as I know the final product will be unlike others. Same goes for vette boxes and arms. If I had to be governed by time I probably wouldn't take the job. Likewise if I didn't have access to a toolroom I wouldn't be able to build them as I do.

I guess we could debate the use of a solid sleeve but I'll just agree to disagree. One thing of interest all the heavy use 12 bolt vettes Tom built for 40 years didn't use either a crush sleeve or solid sleeve. He setup the pattern and loctited the bearings in place. I'm sure you have seen the quality of the sleeves sold today too. Some of the current aftermarket ones will compress with much less effort then say a NOS GM sleeve. I use the Ratech sleeves and they are pretty good. I will be setting up a Ratech solid sleeve tomorrow in fact.

As you say, to each his own which I agree with 100%. Sounds like you are very experienced as well and I do respect that.

Lastly, Glenn I apologize if your thread kind of took off in a different direction from my comments. I won't add anymore comment to this thread. The offer of any help is still open as well.

See ya guys.

Gary

[Glenn B.]

Re: Rear Wheel Bearing Assembly

You guys are both well beyond me in expertise in this area, appreciate your comments.

Gary, I am up to my shoulders on this job - but not yet over my head - if the waters rise further will get in touch. Much appreciated.

Steve, looks like you are local? - are you in greater Vancity? I am on the North Shore.

[Steve G.]

Re: Rear Wheel Bearing Assembly

You guys are both well beyond me in expertise in this area, appreciate your comments.

Gary, I am up to my shoulders on this job - but not yet over my head - if the waters rise further will get in touch. Much appreciated.

Steve, looks like you are local? - are you in greater Vancity? I am on the North Shore.

I'm in Kamloops. Actually in the Dominican as I type for a month, back around 19th Feb. Glad to help out if you need it. PM me for a ph number if you'd like.
Steve

[Glenn B.]

Re: Rear Wheel Bearing Assembly

Steve - interesting, I'm heading to Punta Cana in March. will send you a PM

[Glenn B.]

Re: Rear Wheel Bearing Assembly

OK, I have now solved the mystery of why a second shim was placed between my inner bearing and the spindle flange... it is because when the washer and castle nut are placed on the spindle and tightened against the flange, the washer bottoms out onto the spindle before the bearings are properly seated, so the last guy to mess with the rear bearings added a shim to deal with this problem - how creative....

I am wondering if my spindle flange has been ground down out of spec? I measure it with my micrometer at a height of 1.915 inches? Would this height be within acceptable tolerances? Thanks