'72 C20 Wheel Bearing adjustment/torque?

[72CampSpecial]

Specs: '72 C20 Camper Custom, 3/4 ton, disk brakes up front and drums in the rear.

Ive searched a bunch of post and I'm having trouble figuring out how to properly seat the bearings and torque/set the castle nut once I've re-installed all new bearings and associated parts.

Some post tell me to torque the castle nut to 15 ft. lbs. and then back it off, re-tighten finger tight, then back off to align the cotter pin.

Some post tell me to tighten to upwards of 50 ft. lbs. back off, re-tighten to 30 ft lbs. and then align for cotter pin.

My Chilton talks about tightening the inner adjustment nut (??) to 50 ft lbs then loosening and retightening to 35 and then backing it off to nearest hole lock washer and installing a locknut?? Mine only has a castle nut??

Beyond those instructions in the Chilton they give references to just about every year except the '72 3/4 ton..

Im confused...help appreciated..

[SS Tim]

Chilton generally do better in birdcages than toolboxes.
Haynes IMHO are much better and help bridge the knowledge gap factory manuals assume the user has.
But no matter you should have a copy of the factory manual to refer to.

* VIN/Model Decoders
* Power Team Charts (engine/transmission/gear ratio)
* Post Your Pickup SPID Blazer SPID Suburban/Panel SPID
* RTFM ... Read The Factory Manuals... download 'em here

[72CampSpecial]

Originally Posted by SS Tim

Chilton generally do better in birdcages than toolboxes.
Haynes IMHO are much better and help bridge the knowledge gap factory manuals assume the user has.
But no matter you should have a copy of the factory manual to refer to.

RTFM[/B] ... Read The Factory Manuals... download 'em here[/FONT]

Check...i think i must have been sick the day i bought the Chilton...and the layout/info in it has been less than helpful...All my other manuals are Haynes.

[SS Tim]

Download the factory manual and start reading "FRONT SUSPENSION 3-3" .

[truckdude239]

Therex no torque setting its more of a feel

[72CampSpecial]

Originally Posted by SS Tim

Download the factory manual and start reading "FRONT SUSPENSION 3-3" .

SS Tim.. any suggestions on where might i find the Factory manual to download?

Originally Posted by truckdude239

Therex no torque setting its more of a feel

truckdude239..so, if its technique...can you pass on a "How-To"/some pointers?

Can anyone answer part of the question..is it "turn the castle nut till its snug and then back it off and insert cotter pin" type Technique ....or is it the higher torque example i sighted in my original post?

the higher torque one seems like a lot of torque..

thanks..

[Greasey Harley]

Tighten it down just snug. You should be able to move the washer with a wide blade screw driver. It shouldn't "float around" under the nut, but you should be able to move it, without too much difficulty. The object is to [just] load the bearing. It is kind of a feel thing. Hope that helps.
-Russ

[72CampSpecial]

Originally Posted by Greasey Harley

Tighten it down just snug. You should be able to move the washer with a wide blade screw driver. It shouldn't "float around" under the nut, but you should be able to move it, without too much difficulty. The object is to [just] load the bearing. It is kind of a feel thing. Hope that helps.
-Russ

it does..thanks!

[71Dually]

Download the factory chassis service manual here to your computer.

Follow the directions in the factory manual.

Nothing is better than a factory manual.

[SS Tim]

Actually I pasted in my currently unused signature links just so you could download a manual up in post #2. :-)

[71Dually]

The adjustment info in the factory manual is what is required for longevity and safety. Do things right and you do things once. They cost a bit more then the Chilton & Haynes books but they save time and money in the long run. They also prevent frustration and failed repairs.

Can't tell you how many steering knuckles I have seen in the junk yards ruined from improper wheel bearing adjustment procedures.

I did download the manual here but the hard copy book was the first purchase I made when I bought my truck. I bought the manual before I even took the signed title in hand to transfer it in my name.

Faxon auto literature in Riverside, CA sell originals and reproductions. Without the forum vendors here we might not have this forum so please support the vendors here on the board, they should have reproduction copies available for purchase also.

P.S. The factory manual says torque to 40 lbs. with additional information on the proper procedure to set the required preload on the bearing. The required preload can only be obtained with the procedure outlined in the manual. The bearing must be preloaded, if not it can affect alignment, steering geometry and bearing wear. Wheel bearings are critical components. Improper preload can lead to premature bearing failure, spindle damage, serious damage to your truck and even death if you are involved in an accident as a result of a repair failure.

Stay thirsty my friends, use the factory manuals. My safety thanks you.

[71K20chevy]

On my 71 3/4 ton, we tightened them snug and backed them off about 1/8 turn. Wheels haven't fallen off yet.

[72CampSpecial]

Originally Posted by SS Tim

Actually I pasted in my currently unused signature links just so you could download a manual up in post #2. :-)

Dohh....My aplogies.. i totally missed that...sometimes reading things on my phone doesnt wk so well!

[Norcal72]

I used the Timiken bearing website. Using these directions, about 7,000 miles and no noise or issues.

http://www.timken.com/en-us/solution...ts/Vol1No5.pdf

[davepl]

It's in the factory service manual. That's where I got my info to do my 3/4-ton. Don't stay home without it.

It's also different for C10 vs C20 vs C30. So if someone tells you one thing, make sure it's for your model.

[Andy4639]

Well I have tightened several vehicles as stated and never had a problem.
The way I do it is tighten until the wheel want move anymore and then tighten it some more. Then back off enough to spin the calipar by hand good because once the wheel is in place it adds torque to spinning it. Then align the cotter key and your done.
I have never seen any Chevy with double nuts on them.
One more thing most used spindals have the race inside of them from the old bearings. These need to be pressed out of the hub and a new ones installed to match the new bearings.
This is a new rotor but you can see the race inside the hub, on a old hub this needs to coome out and new installed front and back.

[davepl]

Originally Posted by Andy4639

Well I have tightened several vehicles as stated and never had a problem.

And GM tightened approximately 5 million of them their way over those years (10M if count both sides I suppose), basing it off metallurgical testing, the input of probably dozens of certified engineers from good universities, then went through billions of miles (literally) of service warranty experience.

I do a lot of things "my way" too. Doesn't make 'em right.

Your way is admittedly exactly what I did until I was 40. Since the restoration I'm working on is something I want "right", I looked it up. I was surprised by the fact that both the procedure and the torque values are quite different for the C10 vs C20, which told me there is no one universal "catch all" way of doing them right.

And if I seem a little paranoid about getting wheels on right, here's why. Of course it was the wheel, not the rotor, but I don't think that cotter pin is bent to spec :-)

[Andy4639]

Originally Posted by davepl

And GM tightened approximately 5 million of them their way over those years (10M if count both sides I suppose), basing it off metallurgical testing, the input of probably dozens of certified engineers from good universities, then went through billions of miles (literally) of service warranty experience.

I do a lot of things "my way" too. Doesn't make 'em right.

Your way is admittedly exactly what I did until I was 40. Since the restoration I'm working on is something I want "right", I looked it up. I was surprised by the fact that both the procedure and the torque values are quite different for the C10 vs C20, which told me there is no one universal "catch all" way of doing them right.

And if I seem a little paranoid about getting wheels on right, here's why. Of course it was the wheel, not the rotor, but I don't think that cotter pin is bent to spec :-)

Here is what the manual's say for the 71 and 69 models. Sorry I don't have the 72 manual but it should be the same as the 71 pretty much. I think I get it pretty close for both the way I do it. He can decide for himself though. As I stated I turn the rotor by hand until it's easly rotated. I also don't like backing off of a nut to install a cotter key. I like to tighten the nut instead of loosening it. Just good practice after spending 35 years in Nuclear maintance tearing pumps and motor's a part for inspections and seeing what happens when a nut is backed off to align a cotter key.

[imjeff]

Andy gives the procedure I've used for a long time without issue. Make sure your races (inner and outer) are seated all the way in the hub. Make sure you replace races with bearings and use your used bearings with their original races. Don't pack the inside space between the bearings with grease....it acts like a centrifuge and can separate the excess grease causing issues. Four wheel drives use two nuts on the spindle. When you put it together the extra torque while spinning is to make sure everything seats. Then you back it off just enough to have free rotor spinning without any end play. It's not a linear accelerator! You can always jack up the wheel in a couple days and make sure you don't have any play. Good luck!

Jeff

[72CampSpecial]

thanks everyone! this is exactly what i needed...(andy4639 thanks for the pics!)

One more question..3/4 ton is the 20-30 series right?

Truck is on hold until I get back this weekend..taking the wife on an overnight trip for our 13 yr anniversary...so few more days and then back on the road hopefully!

[71K20chevy]

3/4 ton is 20 series, 1 ton is 30 series.

[Andy4639]

Also make sure you keep the used bearing's as a set with the races if you take one a part to clean and repack.
Your welcome.

[72CampSpecial]

so...all back together...almost. When i was putting the caliper bolts back in i noticed one of the calipers is missing the bushing that the caliper bolt goes through...so off to the parts store tomorrow.

[Andy4639]

Originally Posted by 72CampSpecial

so...all back together...almost. When i was putting the caliper bolts back in i noticed one of the calipers is missing the bushing that the caliper bolt goes through...so off to the parts store tomorrow.

I guess that's better than finding out you have left over parts after your done!