Wheel bearing torque

[JustLarry]

Hi guys,
I know I should be able to find it with a search, but maybe starting a thread about my wheel bearing eating Sport Trac will actually find a solution.
I've had this car (01 Explorer Sport Trac, RWD) for well over 200,000 miles.
I have changed both front spindles at least once, I think I did the right side twice now. I can not tell you how many bearings I have gone through. It's always the outer, but I do them both with new races and seals. I have bought new rotors, just to get the new races already installed thinking maybe I was installing the races wrong.
I knew I wasn't installing the races wrong, I jut couldn't think of anything else to cause this car to eat bearings this way, and it's gotten worse as time has gone by. In August 2016 I did one spindle, and inner and outer bearing on both sides. The right side bearings (I/O) have been done twice since and it's growling again. The noise coming from the left side today made me take it off the road and pull the rotor.Outside bearing was far enough out of round that I needed a hammer to get the rotor off the car. If I had gone to work, I would have been coming home on a tow truck, again.
Anyway, I got a book, it's not Chilton, but it says that the bearings should be torqued to 28 FT.LB. (Go tighter at first while spinning the rotor, then loosen and torque to 28 FT. LB.
I just read something somewhere that said 17 FT LB on a Ford/Mazda Ranger B 2000. Have I been over tightening all these bearings?

 

[JustLarry]

UGH! I found that book.It's a Haynes repair manual, and my memory of what I read in it is not accurate.
First off, I remembered the number to be 28, and it's actually 18-20. The real kicker is that the value is in INCH lbs, not FOOT lbs as I have been thinking/doing.
Conversion chart I found says that there are 12 inch lbs in a foot lb. I don't see how that can be. I've been torquing these bearings to28 FT lbs and still turning the rotor by hand.
If that conversion is right, 20 inch lbs is less than 2 foot lbs. I can make it tighter than that with my fingers.

 

[sickwilly]

When I had my RWD sport trac I went thought bearings too. I ended up paying to have them replaced thinking I was doing something wrong. Eventually the noise came back. So I went back to doing them myself like on my boat trailer. I don't even get our the torque wrench any more. Seat them, loosen, up, them go barely more than hand tight.

 

[koda2000]

When I had my RWD sport trac I went thought bearings too. I ended up paying to have them replaced thinking I was doing something wrong. Eventually the noise came back. So I went back to doing them myself like on my boat trailer. I don't even get our the torque wrench any more. Seat them, loosen, up, them go barely more than hand tight.

That's the way I've done it all my life. Snug em down, spin the rotor, loosen them back up and let the weight of my wrench tighten the nut just barely. Basically your're looking for zero-lash. If you have to move the nut to line up the cotter pin, loosen it a tad. A little too loose is better than a little too tight, because as the bearings and rotor heat up they expand a little. 28 foot pounds as the final torque is about 28 foot pounds too tight. No wonder why your're going through wheel bearings.

 

[ptf18]

AHHHH.... its INCH POUNDS.... NOT....... FOOT POUNDS.

and YES 28 INCH POUNDS ( maybe its 20 INCH/POUNDS, whatever the book says) will be a just abit tighter than using your fingers.

If your going to do it without a torque wrench as other have done (myself included) follow their procedure.

If your going to use a torque wrench get a INCH/POUND torque wrench. Dont use a FOOT/POUND wrench and attempt to roll down the setting of the FOOT/POUND wrench to just barely over 2 FOOT/POUNDs (that would equal 24 inch/pounds)

Best of luck

 

[shucker1]

Seems like a little too much pre-load on the bearings by going to 28 Ft\Lbs.

Surprised they even lasted a few miles.

If your going to use a torque wrench get a INCH/POUND torque wrench. Dont use a FOOT/POUND wrench and attempt to roll down the setting of the FOOT/POUND wrench to just barely over 2 FOOT/POUNDs (that would equal 24 inch/pounds)

That's the way I've done it all my life. Snug em down, spin the rotor, loosen them back up and let the weight of my wrench tighten the nut just barely. Basically your're looking for zero-lash. If you have to move the nut to line up the cotter pin, loosen it a tad.

 

[ptf18]

Seems like a little too much pre-load on the bearings by going to 28 Ft\Lbs.

Surprised they even lasted a few miles.

I've done it by the book and yes 28 FOOT/POUNDS seems to be a heck of alot of torque. Glad to loosen the nut and do a FINAL torque of 20 something INCH/POUNDS on the nut.

 

[shucker1]

Yes Sir.

Big difference.

Glad it did not totally fail and cause a wreck.

Like we say in my business (Industrial Engines), the instruction book is your bible. Read carefully!