Service Manual says:
-Use a new nut every time
-DO NOT USE IMPACT WRENCH
-155 ft-lbs

I was going to point out that strictly speaking this does not affect "bearing pre-load" but see now that it was discussed in "detail" below

 

What service manual do you have?

 

155 is correct according to shopkey

 

This is becoming a common problem more and more. Try to stay away from so called white box models. Any Chinese made ones are also suspect. You don't have to use GM as they might be Chinese or Korean also (otherwize why are so many failing). National and Timken and SKF just to name a few that I'm familiar with. Also, some sellers offer a lifetime warranty.

 

There are threads on service manuals, but here it is anyway (three very large volumes) http://www.helminc.com/helm/product2...08A&itemtype=N

 

Well changed out bearing assembly on Sat. Amazing my ABS and TC light are both off again. The old bearing has a definite click in it when you rotate it by hand. The new one is as smooth as can be.

Thanks for everyones help.

Theront

 

Importain note: while the torque figure is indeed important, there is no "preload" achieved when torquing the axle nut on this style bearing. Preload is a manufactured feature of the bearing, and axle nut torque does not affect it. The only exception to this is on earlier FWD vehicles where if the axle nut comes loose, the bearing can indeed separate and lose the manufactured preload.

And yes...stay away from cheapo aftermarket parts for this critical assembly, unless you are just repairing an old beater. Stick with OEM; it's still your best bet for a quality replacement.

 

The "axle nut" has nothing to do with wheel bearings. It is what retains the axle shaft. You can remove the axle nut and take out the axle shaft and the wheel bearing will remain bolted to the knuckle and not affected.

The wheel bearing assemblies are adjusted and sealed during manufacturing. They cannot be serviced in the field.

Bill's cautionary statement about using cheap replacement bearings is well-taken. Use only GM bearing assemblies or those from reputable aftermarket brands such as SKF.

 

Now we're getting into semantics. I agree the bearing has the preload "manufactured" into it, but all you have to do to "manufacture it out" is to under-torque the axle nut. Also, while the axle nut torque "should not" affect the preload, I've got a beer and a burger that says it will affect it, especially in marginally manufactured parts. That difference may not be critical, but there will be a difference, usually in longevity!

Maybe we can start an HHR-Myth Busters show!

 

You're close, but...semantics are not involved.

What you've risked confusion with is the preload associated with earlier style wheel bearings that were in fact field serviceable, and did indeed require a particular preload be set by the technician upon assembly.

You are incorrect, in that axle nut torque does not affect bearing preload on modern FWD cars. Once the bearing races (as well as any involved spacer or shim) are seated tight against one another inside the bearing assembly, as manufactured, the force exerted by the axle nut is woefully insufficient to increase that preload. To increase the preload would require tonnage of pressure that is well in excess of what the axle nut could ever produce. Frankly, as the bearing races are hardened to a degree that they simply cannot deflect even under extreme pressure, the huge force required to increase bearing preload would result in destruction of the bearing. There's no "give" in such an assembly.

I mean no offense to you in pointing out these distinctions; my intention is simply to prevent misinformation and/or confusion on the part of others who read this thread.

Let me know where you're located so I can get that burger and beer the next time I pass through!