grafx

I'm going to replace the wheel bearings on my car and want to make sure I'm tightening them correctly. I read an article recently that said 50 percents of the vehicles on the road today have their bearings incorrectly tightened.

grafx

My manual says when first tightening the nut, not to exceed 12 ft lbs of torque. Is this enough to properly seat the bearings? Then it says to back the nut off 1/4 turn line up the cotter pin and attack a dial indicator to properly measure end play. The part that doen't sound right is the 12 ft lbs of torque, it doesn't sound like it's enough.

Also I plan on purchasing a dial indicator but have never used one for setting bearing end play or at all for that matter. What is the proper method for using a dial indicator?

TomP

No, that's fine; that's what the GM manual says to use. I don't use a dial indicator to check for play; you can do it yourself. Put the tire on before you start cranking the bearings back down. (Make sure they're packed with grease, of course.)

Just curious- are your wheel bearings shot? Or are you just replacing them because of age? Have you inspected the old ones?

As you "tighten" the castellated nut to 12 ft pounds, spin the tire forwards. When the nut's at twelve, let the tire coast to a stop. Back the nut off a bit, and tighten it hand tight. Slip your cotter pin thru; if the castellations don't line up with the holes, back the nut off more to get the pin thru- don't tighten the nut further.

Once you're done, grab the top and bottom of the tire, and wiggle it back & forth. The tire should move very slightly, and as you vigorously shake it, you should feel a slight "thud" as the tire stops wiggling. You'll know it's correct, trust me. Put the dust cap on and go for a ride.

The "incorrect tightening" of wheel bearings happens later- when all the extra grease squishes out. You should check your wheel bearings (by doing the 'ol tire wiggle) in a week, and then a week after that, and you'll probably be good. A loose wheel bearing will (1) cause the tire to wiggle more, and (2) your light "thud" will become a more solid "thunk" as you wiggle the tire.

If you overtighten the wheel bearings, they'll bind!! If you're setting the wheel bearings up in freezing weather, make sure to check them again in the summer. They might be too tight.

Now would be a cool time to move to a full synthetic wheel bearing grease. I use Valvoline's Syntec. Make sure the back of the tube mentions something about meeting GM spec.

TomP

Oh- as to using a dial indicator- you set it up on a magnetic base, then you have to "zero" the indiator. The bezel of the dial indicator spins. You should "preload" the indicator by pushing it into the piece you're measuring... just by a bit. I'm sure there's a spec for how far you should go... maybe go 0.50"?

Anyway, after it's set, spin the bezel so the needle points to zero. By doing this, you get a more accurate reading... sort of like how we shouldn't use a 200 ft/lb torque wrench to measure 5 ft/lbs of torque.

You might notice when you get your indicator (or if you look at pictures from eBay) that the needle doesn't point at zero- it's not broken, just spin the bezel.

Oh I've always used my 150 ft/lb torque wrench for the 12 ft/lbs on the bearings, no problems so far (I repack the bearings at every front brake pad change), and they always get set to the proper endplay.

82camaro

Used bearings should spin free, no preload and no looseness. New bearings should have just a little bit of preload. With a new and used bearings spin the wheel and tighten the bearing until the wheel stops spinning. Back the nut off and then adjust the preload if it's a new bearing or adjust until no slack and no preload exists if it's used.

Parrydise7

iTrader: (1)

I was told there was a different way to tighten bearings if you have the Timkin tapered roller bearings versus other bearings. I think I was told that you do not do a preload on Timkins, but I could be mistaken. I would check just to be sure about this, because it is an important subject.

grafx

I don't think any wheel bearings are preloaded. The only type I've heard of that you preload are pinnion bearings and maybe tranny

82camaro

I only use Timkin bearings on all the bearing replacements I have done and always add a bit of preload when they are new. New bearings will wear a little bit with preload or without. Without the preload they will become a little loose after they wear in. I've done this for years and years on way too many cars and trucks and it works for me. It's by no means the only correct way to do it--numerous methods exist that end with the same result.

turningfast

82 Camaro is right. There should be no play and a slight drag ( very slight ).Why would you set up new bearind to have some movement, when that is what diagnosis a bad bearing. Makesure they are packed right to, not just covered in grease.

grafx

I noticed yesterday when I had it up on jacks that on the driverside when I spun the tire you could here the brake rubbing against the rotor and it did make that many revolutions before coming to a stop, now I know this is normal. But on the passenger side when I did the same I couldn't hear the brake rubbing and the tire kept spinning, this doesn't seem normal. Made me think their was something wrong with the caliper but when I'm driving and I brake the car doesn't pull or anything so I don't know, should I be worried?