Front or rear wheel bearing adjustment

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To those of you who have a fair to a lot of auto mechanic experience.
How do you adjust the wheel bearing pre-load.
Do you do them all the same or maybe different on front wheel drive rear bearings as opposed to the front bearing on a rear drive car.

I am experienced but am kind of anal and was wondering how others do it. So this is kinda of a survey.......

I sure like sealed bearings myself.
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The way Ive always done them on my pickup is to tighten down the nut about 50ish ft lbs and back off till the holes for the cotter pin line up.Could be the wrong way but Ive never had one fail in 12 years using this method.
 
on something like a fwd the wheel cv joints get torqued to nearly 200ftlb's, and thats the end of it.

on a conventional rear end i like to tighten down the nut 1/6 turn past finger snug, then spin it by hand a few times, then losen it to the first cotter pin hole.

the real deals idea of using ftlb is probably better than 1/6th, but 50ftlb sounds like alot to me.
 
for FWD cars with ball bearing type of bearings, you do not need to pre-load (although a 2-step loading would be nice) your bearings, just torque it to the factory spec (typically ranges from around 120ft/lbs or more (I've seen some as much as 200+ft/lbs)

If the rear wheel bearings are of taper needle roller type, you will have to pre-load to factory specs first (between 25~40ft/lbs typical), spins the hub a bit or very gently hit all 4 sides with a rubber mallet while rotating the bearing and then back the nut off. Now, finger tighten until snug and then slide in your cotter pin or stake your castle nut to secure.
 
typical GM rwd vehicles call for tightening the nut to around 12ftlbs while rotating rotor, then backing off. I'd have to look up exact specs. Haven't ever had an issue with the ones I've done.
 
Quote:


The way Ive always done them on my pickup is to tighten down the nut about 50ish ft lbs and back off till the holes for the cotter pin line up.Could be the wrong way but Ive never had one fail in 12 years using this method.



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Folks... don't do this. That's WAY too tight.

I agree with Quest's method for tapered roller WHEEL bearings (tapered roller bearings in other applications can be adjusted any number of ways)

On a car, pickup, small trailer, or farm tractor... I snug the nut down to something in the neighborhood of 30-60 foot pounds (while rotating the hub/rotor/wheel/whatever), depending on how big the bearings in question are. Then back off nut, turn it finger-tight, and install the cotter pin.

This can become more complicated when you start messing with bigger applications and/or double retaining nuts (like in 4wd hubs and semi-truck axles). Generally speaking, wheel bearings will live a long and happy life with exactly zero clearance. In applications where adjustment is difficult (due to heavy parts or complicated retaining nut setups), I use a dial indicator and set the endplay between .001" and .005".

That said... I've also seen applications (a Dana 70 differential comes to mind) where tapered roller bearings are preloaded up to .015" (that's TIGHT). I've also seen wheel bearings last for decades after being set way too loose. It goes to show that in light applications, bearings of this design can be very forgiving.
 
When I went to Audi factory training, I was taught to seat the bearings to 30 ft/lb, then back off so the washer under the nut can be moved with your finger nail. This has always worked for me. I have seen bearings set too tight get hot and turn brown. I a situation where the bearings are lubed with gear lube, the bearings can handle a constant preload situation because of the constant flow of oil.
Ted
 
I work for a bearing manufacturer and the concensus in this thread seems to be right on. I want to add that the old timers tell me the best setting for automotive double tapers is roughly 0.003" axial clearance. This provides the longest life for the wheel bearing.
 
Thanks for the replies.

I seat the bearings then loosen. Then when I tighten the nut hand tight it always seems like a lot of play is left. And no I am not a weakling!
My dads 91 Voyager I did it the hand tight way about 60k miles ago. I just re did the bearing pack.

I checked the bearings and the wheels were pretty loose. I also noticed some wear on the washer that seems like it was from the bearing having too much play. Other than that the bearings looked OK.

When measuring the play would you be talking about it measured at the outer part of the drum/rotor?
 
Since I'm the one who brought it up...

I don't find measuring endplay neccesary on your average wheel bearings. Like I said- I only do it when parts are heavy and awkward (heavy trucks), or when the nut retaining system is somehow more complicated than a cotter pin. This would include double nuts in 4wd hubs and any of several novel nut-retaining setups in full-floating hubs.

Anyway, here's how I do it... and it should work just as well for any wheel bearings that you're less than sure about:

Get out your magnetic base dial indicator. Stick the base to some convenient, flat location on the hub (often either between lug studs in smaller applications or on the axle flange gasket surface in larger applications). In cases where there isn't room to stick that magnetic base, this could require some creativity. Now, set up the dial indicator so that the tip rests on a flat and radially uniform section of the spindle. With the bearings adjusted and dial indicator mounted, simply push in/ pull out on the hub and watch the dial indicator. No need to get out a prybar... a firm push/pull is all that's neccesary. If you read between .001" and .005", then you're good to go. If the slots in the retaining nut are too far apart to get within this range... I usually err on the side of a little preload. The only problem with preload is that you can't measure it with something simple like a dial indicator- but one or three thousands of it isn't going to hurt anything.

It might be a bit counterintuitive to simply check axial endplay on a conical bearing- but in my experience, it's the most consistent measurement you'll get out of tapered roller bearings. I've tried measuring wobble and/or radial play... and it just isn't very precise. Just slide yer shaft in and out.
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On 1986-89 Mazda 323's the preload is set with a shim, it's a PITA to check and change.
 
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