tightening a wheel bearing

Donald · May 28, 2012

I am trying to remember what my Dad use to tell me with respect to tightening plain old wheel bearings, and I think it was to tighten with a wrench to set it, then loosen, then tighten with fingers and insert the cotter pin. If you need to move the nut for the cotter pin, tighten rather than loosen.

Doing disc brakes on the boat trailer.

George7941 · May 28, 2012

Sounds right to me. Just don't get it too tight.

JHZR2 · May 28, 2012

The right way to do it is with a dial indicator to set the precise amount of free play on the rotor to FSM spec.

zrxkawboy · May 28, 2012

Originally Posted By: Donald
I am trying to remember what my Dad use to tell me with respect to tightening plain old wheel bearings, and I think it was to tighten with a wrench to set it, then loosen, then tighten with fingers and insert the cotter pin. If you need to move the nut for the cotter pin, tighten rather than loosen.

Correct. When you do the initial "tighten to set it", do this while spinning the wheel.

Kruse · May 28, 2012

30 years ago, I had a automotive tech instructor tell me this: Always set wheel bearing with a torque wrench. However, if a permanent roadside repair is needed, tighten the nut against the grease-packed wheel bearings as tight as you can with a Channel-lock type of pliers. Spin the wheel a couple of turns to reorient the grease in the bearings. Now WITHOUT TURNING THE WHEEL, loosen the nut with the pliers. Then tighten the nut finger tight. Install the outer locking nut (if so used in the application). Insert cotter pin.

mechtech2 · May 29, 2012

The problem with the finger tightening method is that with different cambered and weighted wheels, you will NOT be able to tighten things accurately and consistently.
I tighten them to zero and spin them, then back off 1/2 to not more than 1 flat on the nut.
I don't know how you can do this with a torque wrench. It is impossible except by luck.
And BTW, hot or cold makes a difference.

edwardh1 · May 29, 2012

tighten while rotating til no play, then stop, loosen nut, retighten nut by hand, but if necessary to inset cotter back nut OFF was what I do

Smoky14 · May 29, 2012

Roller or ball bearings??

doitmyself · May 29, 2012

Donald,

For what it's worth, here's what Timken has to say about tightening bearings: http://www.timken.com/en-us/solutions/au...ngs_English.pdf

As a shade tree diyer, the problem I have with all these methods is that they involve "feel", which is something that is hard to learn without someone showing you. Even the Timken bulletin says to initially tighten the bearing until there is a slight resistance. Well, how much is slight? Or, how much is finger tight (300 lb. gorilla vs. 110 lb. weaking?)?

This is always done with the tire/wheel off, correct?

I've done a handful of bearings and everything seems o.k. ....so far!

Texan4Life · May 29, 2012

Originally Posted By: doitmyself
Donald,

For what it's worth, here's what Timken has to say about tightening bearings: http://www.timken.com/en-us/solutions/au...ngs_English.pdf

As a shade tree diyer, the problem I have with all these methods is that they involve "feel", which is something that is hard to learn without someone showing you. Even the Timken bulletin says to initially tighten the bearing until there is a slight resistance. Well, how much is slight? Or, how much is finger tight (300 lb. gorilla vs. 110 lb. weaking?)?

This is always done with the tire/wheel off, correct?

I've done a handful of bearings and everything seems o.k. ....so far!

+1 as a youngen (24) all wheel bearings I have worked on have been sealed bearings. Luckily tho I had a chance to do tapered trailer bearings with an old timer (70). They are really easy to do when you have someone to teach you.

mechtech2 · May 29, 2012

The tire may be on, which causes feel to vary a lot.
But once again, being hot [from brakes] makes a big difference.

Donald · May 29, 2012

This is roller bearings. Everything is new, hub/rotor, bearings, caliper/pads. Right now there is no tire. Its never had the brakes applied in maybe 20 years, thus new disc brakes. Only the shaft is old and it had no rust or pits.

1 FMF · May 31, 2012

http://www.pirate4x4.com/tech/billavista/PDFs/Timkin bearing pre-load.pdf

with any tapered roller bearing setup, you want a small amount of preload. this stabilizes the bearing and give you the most life out of it. too much preload and the bearing will run hot, too little preload or endplay will shorten it's life and worst case let the bearing come apart.

fwiw i did wheel bearings on a cheap 1 axle uhaul trailer that a friend used when relocating from CT to LA California. When she brought the trailer to her house, I was there to help load it, I figured i'd jack it up and see how much wobble the wheels had. it was scary, which is probably why they had signs all over it do not exceed 55 mph. I set those up by regreasing, then tightening down as hard as i could on the bearing nut to make sure the tapered bearing seats, then back off the nut then finger tighten and get it so you can get the cotter pin in with no wheel wobble and minimal wheel drag. You don't want any wheel wobble, and it's harder to seat the hub with the wheel on because of the extra mass. When you spin the wheel you want minimal drag, it should spin and not come to a stop very quick but quicker when there was endplay and wobble. you can experiment with having just the slightest amount of wheel wobble, and see how the wheel/tire spins freely, then put a little preload on and see how it doesn't spin as free. Ideally you'd want to have the rim/tire off and with just the hub use an inch pound torque wrench to set up preload to 10-20 inch pounds, just like a pinion in a rear axle. but you also have to watch out for other sources of friction such as the brakes. the trick when you get the right amount of preload but the nut doesn't line up for the cotter pin or whatever locking mechanism is to remove the nut and run one side of it on some sand paper. This will remove just enough to let the nut be in a different location when you get the right preload and let you get the cotter pin in.

calvin1 · May 31, 2012

Ford's method with the rollers in the D44 TTB front on my Bronco was to tighten the bearing nut to 50 ft-lb while spinning the rotor, back it off a quarter turn and then back to the nearest detent for the lock washer/plate.

The_Eric · May 31, 2012

Yes, some pre-load is necessary. If you don't, the bearing/wheel will wobble some as they always seem to loosen some in operation.

With the Dana 44 in the front of my old Suburban, the (book) method was something like tighten to 50 or 60 lbs while rotating, then loosen X amount of turns or degrees, then tighten to something like 10 or 12 lbs. That's way more than finger tight...

doitmyself · May 31, 2012

Originally Posted By: The_Eric
Yes, some pre-load is necessary. If you don't, the bearing/wheel will wobble some as they always seem to loosen some in operation.

With the Dana 44 in the front of my old Suburban, the (book) method was something like tighten to 50 or 60 lbs while rotating, then loosen X amount of turns or degrees, then tighten to something like 10 or 12 lbs. That's way more than finger tight...

I interpreted the "heavy duty" audience of the Timken pre load tech sheet to mean that it was for semi trucks, etc..

The pre load tech sheet contradicts my automotive Timken tech. sheet (above)that states one wants a small amount of end play.

Kestas?

Kestas · May 31, 2012

I was told that automotive double tapers achieve maximum bearing life when the axial clearance is set to 0.003".

In the absence of a dial indicator, I follow the following procedure:

- Tighten axle nut while turning the hub (with or without wheel) until the hub is hard to turn. This is important to properly seat the races should there be any burr or debris.
- Loosen axle nut until slack. Don't turn the hub.
- Tighten axle nut finger tight, or until resistance is felt.
- Lock it as close to that position as possible.

mechtech2 · May 31, 2012

I never heard of preload in a tapered roller bearing for automotive hubs/wheels.

Another option is to consider the threads per inch of the nut, and loosen the nut by a fraction of a degree accordingly, to get your .002" freeplay.
This should be very accurate.
[After spinning while seating the bearings at light torque]

Like I said, 1/2 to not more than one flat loose.

Kiwi_ME · May 31, 2012

Originally Posted By: mechtech2
I never heard of preload in a tapered roller bearing for automotive hubs/wheels
I'm sure I was taught to leave them slightly loose in high school auto shop but after engineering school and 30 years life experience I now know that is wrong. A tapered roller pair must have a preload to track correctly. A running clearance and/or too much grease is more likely to damage them than slightly too much preload.

tightwad · May 31, 2012

I never heard of preload in a tapered roller bearing for automotive hubs/wheels.

Another option is to consider the threads per inch of the nut, and loosen the nut by a fraction of a degree accordingly, to get your .002" freeplay.
This should be very accurate.
[After spinning while seating the bearings at light torque]

Like I said, 1/2 to not more than one flat loose.I

think Mechtech2 has it about right. Go check old FSM and Motor manuals from the 50's through 70's. They almost always want clearance in a tapered roller bearing. I tighten mine while spinning the wheel, and then back off until the cotter pin will just fit through one hole or the other. This is usually about 1/8 of a turn. 43 years of packing bearings and have yet to lose one.
Ball bearings as used by GM in the 50's MUST be preloaded to center the balls in the race.

tightening a wheel bearing

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