HUB Assembly Replacement

[StevieC]

If wheel nut torque was really important we would see hub failures all over the place as people have their tires rotated, changed and switch to seasonal tires because you know the tire-busters don't give 2 horse poops about your vehicle and what the actual torque is supposed to be.

Furthermore those shops that actually get out torque wrenches to verify their readings, when was the last time they were checked for calibration? Most use them from the package and never check their calibration ever. Imagine the thousands of vehicles they have been on day in and day out and you think these are accurate and doing the right job? I doubt it.

Again I repeat of the literally tens of thousands of vehicles my dad has serviced over many decades using the gun to tighten the bolts and re-check for tightness once after has never resulted in a hub failure. Now he doesn't tighten them to the shear point but when the gun stops turning the nut, just a little more from there and that's it.

No wheels fell off, no bolts sacrificed, no hub failures, no warping of brake rotors/drums, no stud problems.... It's over blown, Torque this Torque that. It does have some uses like for head bolts or when bolting into sensitive metals like Aluminum but not everything needs an official torque all the time. "Mechanic Tight" is fine for most things.

 

[MarkM66]

Originally Posted By: StevieC
If wheel nut torque was really important we would see hub failures all over the place as people have their tires rotated, changed and switch to seasonal tires because you know the tire-busters don't give 2 horse poops about your vehicle and what the actual torque is supposed to be.

Furthermore those shops that actually get out torque wrenches to verify their readings, when was the last time they were checked for calibration? Most use them from the package and never check their calibration ever. Imagine the thousands of vehicles they have been on day in and day out and you think these are accurate and doing the right job? I doubt it.

Again I repeat of the literally tens of thousands of vehicles my dad has serviced over many decades using the gun to tighten the bolts and re-check for tightness once after has never resulted in a hub failure. Now he doesn't tighten them to the shear point but when the gun stops turning the nut, just a little more from there and that's it.

No wheels fell off, no bolts sacrificed, no hub failures, no warping of brake rotors/drums, no stud problems.... It's over blown, Torque this Torque that. It does have some uses like for head bolts or when bolting into sensitive metals like Aluminum but not everything needs an official torque all the time. "Mechanic Tight" is fine for most things.


Are you confusing lug nut torque specs with axle nut torque specs?

Trav was referring to axle nut torque specs.

 

[StevieC]

Even that is fine with "Mechanic Tight" versus "Torque Spec Tight" So long as it's not an insane amount of over-tight.

I can count probably on one hand the times that my dad actually looked up Torque Spec's for something. Usually for Head R&R's or Head Gaskets or engine rebuilds. The rest... "Mechanic Tight" and never had any issues.

Perfect example was Chrysler 2.2 / 2.5 litre engines which had head gasket failures would always advise tightening down the heads to a certain torque and we found from experience that leaving the bolts on the left side of the head just a tad looser than official torque spec would result in the gasket not failing a 2nd or third time.

This also did well for the Turbo 2.2L Chrysler engines which were known for head gaskets. In these leaving all the head bolts a tad looser than official spec allowed the gaskets to last longer than those all snugged down to proper spec due to poor design of the head / block not allowing adequate cooling can causing heat expansion issues between the head/block which would kill the gasket over time.

 

[Trav]

A lot of mixed metal engines in that era had issues, the solution was a multi layer steel gasket with a PTFE coating to allow the slight movement necessary to prevent gasket tear, not leaving the bolts on one side looser.

The difference of 18 ftlb on some cv axle nuts resulted in much shorter life in some GM models. Other manufacturers have a very specific tightening sequence eg tighten to 300 nm back off 1 turn, tighten to 40nm plus x degrees. That is not being accomplished with a zip gun or half arsed close enough tightened.

 

[StevieC]

Yes but during the time of the failures just happening it was a solution that worked. We realize now that it was different expansion rates and gasket upgrades made the difference thereafter.

As for the tightening sequence etc. I have already admitted that there are some instances where it is absolutely required. In others it is not.

As for GM well let's just say that they can blame whatever they want but they are usually the cause of their own problems, they have a History of this as do other manufacturers like Subaru to name another.

 

[Trav]

It was known back then too, Chrysler and the aftermarket were already selling revised gaskets very early on.
I don't know what your problem is with GM and Subaru they have had their share of problems and some real good cars and engines like everyone else.
Hacked work many times causes more problems than the manufacturers defects.

 

[StevieC]

Whatever you say.

 

[Kestas]

Originally Posted By: nobb
Originally Posted By: Kestas
Our company makes automotive hub units. Axle nut torque is important. Our company is in constant battle with automotive service departments that simply gun them on. It tees us off because it increases our warranty costs with no way to prove the service departments are at fault.

Dig out the proper torque spec and tighten the axle nut to that specification.

Can I ask why? Looking for a technical, not anecdotal evidence. I'm talking about applications where the axle nut torque has no affect on the bearing pre-load. What exactly is affected in such a case?

The clamp load from axle nut torque does have an effect on bearing preload. Even though the aassembly is clamped through the inner rings butted up to each other, there is still flex in the assembly. It's not like clamping on a solid rotor or some other solid chunk of metal. Some internal geometries of a bearing are measured and controlled on the order of microns. Overclamping can wreak havoc with internal design preloads.

You may not get the bearing to fall apart within a week after improper axle nut torque, but you may not get 150K from it either. Bearing life is critically dependent on preload.

 

[Trav]

Originally Posted By: StevieC
Whatever you say.


Not what I say but accepted industry standards.

 

[beadvised]

I replaced the HUB assembly on the right side. The noise is still there. When I'm going from 25-45 MPH I'm hearing a grinding/growling sound. When I go down a hill or slope doing those speeds it sounds real bad. I'm thinking it may be the left side driver HUB assembly. What else could it be?

 

[SatinSilver]

Originally Posted by Kestas
Our company makes automotive hub units. Axle nut torque is important. Our company is in constant battle with automotive service departments that simply gun them on. It tees us off because it increases our warranty costs with no way to prove the service departments are at fault.

Dig out the proper torque spec and tighten the axle nut to that specification.


What about putting large, yellow/orange labels warning of the importance of the proper torque requirements. Maybe with a mini-chart of makes/models that the assembly pertains to and put the proper settings next to it.

 

[SatinSilver]

Originally Posted by beadvised
I replaced the HUB assembly on the right side. The noise is still there. When I'm going from 25-45 MPH I'm hearing a grinding/growling sound. When I go down a hill or slope doing those speeds it sounds real bad. I'm thinking it may be the left side driver HUB assembly. What else could it be?


It very well could be. A friend wanted me to ride in his 04 Corolla that had a bad wheel bearing. I thought it was the front passenger side and the shop said it was the rear driver's side. I was riding in the front passenger seat. So the sound can be tricky identifying by noise. You can always see if the noise changes when turning left/right while on the hwy.

 

[cjcride]

A good shop will have a Chassis ear tool that has little microphones that are placed on the vehicle. They isolate the noise.

 

[beadvised]

I took it to my actual mechanic. He says it's the bearing in the transmission making the noise. It only makes the noise when I get around to 25MPH or higher. When I let off the gas between 25-40 going down a hill it sounds like a growling noise. I'm taking it to a transmission shop on Monday. I still think it's a HUB assembly issue. We shall see.