Who leaves out their "crush" sleeves?
 

I've been leaving out the crush sleeves in my trailing arms for about 10 years on the suggestion of a very reputable Vette rearend specialist. Much easier to set up, and no failures. Anyone? I also leave them off my pinions as well. I set em up like a front wheel bearing for the most part. I can't wait to see the responses to this one

First of all they are not crush sleeves, and second leaving them out is THE most common cause of failure of serviced wheel bearings that I see when my customers bring them in for service. You guys that insist on re-engineering everything get me. You are begging for a failure. As for the rear end, good luck with that set up.

1-Crush sleeve=nickname (must've worked since you knew what i meant).
2-My records reflect i've been "begging" since 93 (some in 10 second drag cars)
3-I'm not trying to impose this on anyone-just curious if any others here did it.
4-In my shop the most common reason for failure is lack of service. Because they're such a pain to disassemble it never gets done.
5-So, I also machine about a thou off the axle (where the inner bearing goes) so i can remove and service easily

Trailing Arm
 

I have never left the sleeves out. But I did cut down the axles to about 0.0015 oversize so the bearings can come off easier (40yrs ago). A shot of CO2 on the axle also helps. When Loctite came along "a drop" of Blue Loctite AFTER fitting the shims with about 0.001 oversize is all you need.
dso

GTR1999 probably knows that bearing setup as well as anyone, and he uses the spacers. That's good enough for me.

Crush Sleeves
 

I have been calling them crush sleeves for 40 years. So what are they called?
dso

Spacers..and shims.. but you're not alone in calling them crush sleeves

Crush sleeves are for pinion bearings, and they actually crush to achieve a preload.

Finally, just to weigh in on this.. I use the spacers and I have slip fit my bearings

I wouldnt even do that, but he is recommending slip fit and taking the spacer and shim out. I do hope I dont meet him on the road.

Out of curiosity why would the spacer be left out? .. What would be used to replace it? ..

Seems easy enough to dial in the proper thickness of shim in order to achieve the desired end play, spacer included.

I deal with custom machinery design every day as an engineer.
A little bit of background from NTN bearings may help clear up any hearsay, or "it works alright for me" so it must be right type of opinions.

In any roiling bearing the inner ring is properly secured on the shaft or the outer ring in the housing.
It is important that they should not slip with each other while the bearing operates. For this purpose a suitable interference is generally given to the mating parts. If the interference is not sufficient for the applied load, clearance is developed between the shaft and inner ring, thus the inner ring rotates slightly slower than the shaft e.g. slip occurs at the mating surfaces. This phenomenon is called "creep".
Creep causes abrasive wear of shaft, vibration, abnormal heat and ultimately the performance will be unsatisfactory For this reason, sufficient interference must be given to the mating parts. On the other hand, excessive interference reduces the initial bearing internal clearance and leads deformation of the bearing rings, causing the bearing to again give unsatisfactory long term performance. It also makes it difficult to mount and dismount the bearing. Therefore it is important to select the suitable amount of interference.

Types of fits
http://i161.photobucket.com/albums/t...te/ntnfits.jpg

In addition a couple of other points.
1) Tighter interference should be given as applied loads increase.
2) For vibration and fluctuating loads, tighter fit should be given.
3) The larger the bearing the tighter the interference should be.

All this comes from bearing manufacturers design guidelines

Wow, I used to have to fight these battles here on my own. I now have some help. Nev has given you the technical reasons this is not advisable, here are some practacle ones. If you lose nut or break an axle, you may lose a wheel or at minimum you will experience accelerated wear like this.
http://216.77.188.54/coDataImages/p/...OldComp394.jpg

On the contrary, his explanation states: For this reason, sufficient interference must be given to the mating parts. On the other hand, excessive interference reduces the initial bearing internal clearance and leads deformation of the bearing rings, causing the bearing to again give unsatisfactory long term performance. It also makes it difficult to mount and dismount the bearing. Therefore it is important to select the suitable amount of interference.

I have always maintained that the existing GM design has excessive interference, and promotes excessive (bearing) wear. From a practical side, I know that I have used slip fit bearings for many years with absolute success. One example is a 247K bearing life and still going on a C3 that previously had the bearings and spindle for lunch at the "normal" 60K interval.

As for loosing a nut, or breaking an axle, I have never seen a nut loosen (at least I find this very hard to imagine if properly torqued. And yes axles do break, but mostly from severe abuse - but on a disc brake Vette, the disc will hold the wheel in place long enough to come to a safe stop.

Plasticman

Well I HAVE seen the end of the threaded shaft break off. And, can you tell me how you can torque a nut with slip fit bearings and no spacers as mr. Razzle Dazzle suggest? I think that is quite impossible.

I am really tired of arguing this. Tell these guys that the the wheel will not come off of a disc brake car. Both did and put their A$$ES on the hard ground.


http://216.77.188.54/coDataImages/p/...OldComp393.jpg

Sorry you are tired of arguing (but then why respond to comments on the forum?).

But I agree, do not leave out the bearing spacers & shims. They perform a valuable service in keeping the assembly aligned and spaced (maintaining proper clearance) correctly. And as you pointed out, you cannot torque the nut properly without the spacers/shims.
The main reason for cutting down the spindle to make the inner bearing a slip fit, is to set the bearing clearance properly to the bottom end of the spec (.001" end play), which will prolong bearing life, maintain rear wheel alignment more tightly, provide less lateral runout of the rear disc rotor, and result in better overall handling. It also allows easy disassembly of the spindle for inspection and maintenance.

Your pictures are informative, but fail to see how the spindle could come out when the disc brake caliper should of prevented axle movement that far. If the spindle breaks out toward the outer bearing, I could understand it. I would not advocate doing the slip fit on a drum brake Vette, but have never seen an issue on a disc brake one. Perhaps me and my friends have been "lucky", but then again that's life (some are lucky and some are not).

Plasticman

I could imagine the ears breaking off the calipers quite easily. Once the inner bearing is gone there should be a lot of bending load, in the wrong direction, on those ears. The ears are a lot thinner than they are wide. And they are only castings...

Yes, this is exactly what happened in both of these cases. The ears broke off the calipers. They are cast iron and are not designed to take that kind of punishment. Both cars hit the ground and both took fenders with them. Luckily no injuries. As for setting up the bearings. When set up with a dummy shaft or tool, there is no reason you cant get a very good set up even in the .001 range, and still maintain the added safety of pressesed fit.

Thank you for your information, and I understand what happened (now).

Wish you had told us the whole story before (it would of saved a lot of back & forth).

Plasticman

As i said ORIGINALLY. I set em up similar to a front wheel bearing. THOSE nuts don't come off (at my shop). I didn't start an argument. I just shared something that's worked for me, that someone else shared with me. DON'T DO IT IF YOU DON'T WANT. bUT DON'T TELL ME IT WON'T WORK WHEN IT HAS FOR THOUSANDS OF COMBINED MILES ON "DRIVERS" AND 10 SECOND dRAG cARS, AND EVERYTHING BETWEEN. OOPS on the caps

You got the reaction you wanted/expected, didn't you?:)

The automakers of the world could have saved billions over the years by following your lead if it really was a good idea. I guess they thought not and put in the extra effort (parts).:D

I've only been working on midyears for 40 years or so, but maybe I missed something along the line; with no spacer or shim, how do you set spindle end play to .001"-.0015" and avoid preloading the bearings? :rolleyes:

http://img.villagephotos.com/p/2002-...on(Medium).jpg

:cheers: