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Dave K 09-16-2011 02:55 PM

Wheel bearing adjustment question
 
1 Attachment(s)
The on line shop manual says to torque the front wheel bearing to 33ft lbs? Am I reading this wrong? Is it a miss print? Have any of you set them to 33 ft lbs Seems really tight.

Thanks

Dave

Wrenchbender Ret 09-16-2011 04:08 PM

Re: Wheel bearing adjustment question
 
That is way too tight. It probably means just to seat them. My meathod is snug it up & back it off till the nut just starts to turn freely. Then tighten it down enough to line up the cotter pin holes. The brgs. should have no free play in them. This gives a little room for expansion.

OrrieG 09-16-2011 05:46 PM

Re: Wheel bearing adjustment question
 
I'm with wrench bender. You will be able to feel if they are to tight or two loose. Tighten to seat, back off tighten until you feel it to bind a little then back off to where the cotter pin will fit. Make sure they are well lubricated but that there is not any lube on the compression surfaces of the bearing or washer. I always recheck them after a few hundred miles and the grease has had a chance to heat up and disperse.

gearheads78 09-16-2011 06:17 PM

Re: Wheel bearing adjustment question
 
It clearly says that is one step before you back the nut off to acheive the proper backlash.

Dan in Pasadena 09-16-2011 07:31 PM

Re: Wheel bearing adjustment question
 
As it was taught to me (& I was SUPPOSED to teach H.S. Auto Shop...remember that once existed?) tighten the nut til you can just move the flat washer on top of it using a RADIAL motion turn of a flat screwdrive. NOT by prying. That washer has grease on it so it'll move by prying no matter how much you tighten. Then, once it's that tight go to the nearest opening on the castelated nut to put the cotter pin in.
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dwcsr 09-18-2011 06:44 PM

Re: Wheel bearing adjustment question
 
Re read the instructions. It says torque to 33 # spinning the wheel and then back off to the nearest cotter pin hole. If your not working on a 2 ton truck with ball bearings instead or taper bearings then these directions are not for your truck.

Coupeguy2001 09-18-2011 08:18 PM

Re: Wheel bearing adjustment question
 
The 33# IS CORRECT. Only on the 2 ton models do you back off to put the cotter pin in. On the half ton, you get 90 degree holes in the spindle. In AZ, i turn it tghter till the cotter pin lines up. 115 degrees outside means the spindle will stretch just that much more.
If you torque it to around 5 or 6 lbs, when the axle heats up, the spindle stretches and you lose all your bearing preload.
The ball bearig is supposed to be installed in a preload sutuation where the tapered roller doesn't need as much. The tapered roller has so much more contact area, that to torque it that high would induce excessive drag, creating enough heat to ruin the grease's lubricating properties, galling the bearing surfaces.
I have driven my 57 about 285,000 miles, and I can tell you i didn't believe it at first and after changing both the outer bearings R+L every year 3 years running, I did what the book calls out for, and they last about 10 years.
You can hear the bearings make noise when they are flatspotting, and you can feel it in the steering wheel. If they flatspot enough, they make a SNAP SNAP noise at speeds above 50 mph in a turn.

mr48chev 09-19-2011 12:57 AM

Re: Wheel bearing adjustment question
 
Quote:

Originally Posted by Wrenchbender Ret (Post 4902791)
That is way too tight. It probably means just to seat them. My meathod is snug it up & back it off till the nut just starts to turn freely. Then tighten it down enough to line up the cotter pin holes. The brgs. should have no free play in them. This gives a little room for expansion.

That is pretty well close to the same way I have done it for the past 49 years since I was a 15 year old sophomore in high school auto shop class and the teacher Bill Palmer told us neither tight nor loose is how to adjust the bearings.

I usually tighten the nut so that it is just tight and then spin the wheel/hub and back off a bit and take it up until it is just tight and line up the hole for the cotter key.

Grumpys Truck Parts 09-19-2011 01:52 PM

Re: Wheel bearing adjustment question
 
Quote:

Originally Posted by Coupeguy2001 (Post 4906348)
The 33# IS CORRECT. Only on the 2 ton models do you back off to put the cotter pin in. On the half ton, you get 90 degree holes in the spindle. In AZ, i turn it tghter till the cotter pin lines up. 115 degrees outside means the spindle will stretch just that much more.
If you torque it to around 5 or 6 lbs, when the axle heats up, the spindle stretches and you lose all your bearing preload.
The ball bearig is supposed to be installed in a preload sutuation where the tapered roller doesn't need as much. The tapered roller has so much more contact area, that to torque it that high would induce excessive drag, creating enough heat to ruin the grease's lubricating properties, galling the bearing surfaces.
I have driven my 57 about 285,000 miles, and I can tell you i didn't believe it at first and after changing both the outer bearings R+L every year 3 years running, I did what the book calls out for, and they last about 10 years.
You can hear the bearings make noise when they are flatspotting, and you can feel it in the steering wheel. If they flatspot enough, they make a SNAP SNAP noise at speeds above 50 mph in a turn.

Coupeguy2001 is correct. The tighten up and back-off method is applied to tapered roller bearings, these ball bearings need to be torqued.

dicer 09-22-2011 05:31 AM

Re: Wheel bearing adjustment question
 
For ball bearings you tighten first to seat everything then back off and then snug close to finger tight, and a bit more. With rollers they run a bit more loose, about .001 or so clearance.

Coupeguy2001 10-05-2011 03:03 PM

Re: Wheel bearing adjustment question
 
GM published a manual and covered their methods back in the day under warranty. If they were wrong, even at the rediculously low price of $3 for outer bearings and $20 for inners, that would have cost them $millions$. Go with the manual that the manufacturer puts out. They know their product better than you......They designed, built and tested everything they sold.
Even the liability insurance claims and lawsuits would have made the General bankrupt 50 years ago if they were wrong.

mr48chev 10-05-2011 04:02 PM

Re: Wheel bearing adjustment question
 
I'm not saying that the manual is wrong but it does go against what I was taught and have taught. The wheel bearings in my 48 have over 100,000 miles on them and have never given me a problem after adjusting them just like Orrie and Wrenchbender said the learned to do it.

I usually tighten the nut up to put a preload on the bearings back it off and then tighten it again just so that I get to the closest slot to being just tight.

I've found that if you just tighten the nut until it tops and put the key in, quite often the bearing will loosen up in a few miles. I've followed behind the guy who did that at one work place correcting what he had done before he was asked to leave the place. It isn't fun doing someone else's comebacks for the first month you work in a new shop.

But a bigger contributor to bearing failure is having someone do a haphazard job of packing the bearings. I've seen too many that didn't get packed right. Dabbing a bit of grease on the outside of the balls or cone and then filling the hub with grease expecting it to "flow" into the bearing doesn't contribute to long bearing life.


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