This Flat Makes Me Mad!

Went out to check the trailer over today.

Just paid good money a year ago to have the brakes checked and bearings all repacked and so forth; haven't pulled the thing over 300 miles since.

I ABSOLUTELY HATE THE GUY THAT STARTED THE RUMOR THAT YOU ARE SUPPOSED TO "BACK OFF" THE WHEEL BEARING PRE-LOAD ADJUSTING NUT.

Yep, every darned one of 'em is loose. Now, I gotta do all that before I can even hook up. That really torques me off!

Guess if ya want something done right, ya gotta do it yourself. :>(

Allan

bearing manufacturer says tighten nut to

50 ft lbs of torque , then back off 1/6 of a

turn.

Some where here I have the step by step

procedure from bower/ bca for assembling and

tightening tapered roller wheel bearings.

george

• interesting

After the bearing/hub is correctly repacked and reassembled, the tire/wheel is rotated by hand while torquing the nut to 12 ft lbs (depending upon the size of the bearings, of course).

If the keyway lands "between the grooves" ya continue to tighten to the next groove and until the key can be inserted. Under no circumstances should the preload be released and if assembled this way, they will darn near run forever.

That old fashioned "back it off" theory is a hand-me-down from the days of ball bearings and is an absolute "death warrant" for a tapered roller bearings. They will then in time and with use, wear/loosen and the entire load only rides on the "edge" of one roller at a time instead of being distributed evenly across the entire bearing surface(s).

I dunno. Trouble is, 'bout 80% of the guys with wrenches still back 'em off just as they did all those years ago.

I should have stood there and watched them do the job I guess. :>(

Allan

Have to disagee with you.

A friend of mine thought as you do. EVERY wheel bearing he serviced, he "pre-loaded", starting with his own 1979 Ford pickup.

He was going on a trip, and re-packed his front wheel bearings (4 X 4), and was PROUD of snugging them up. One side failed within 100 miles, and the other before he got back home.

He wound up working at the local Cenex, and our shop got to haul in and repair several trailers and medium-duty trucks he had "pre-loaded" the wheel bearings on.

At our shop, we have always followed manufacturer's instructions when available, or set up wheel bearings WITHOUT preload, and I can't recall even ONE single instance where we have been asked to warrantee a wheel bearing job, or EVER heard of one of our jobs failing.

YES, you preload differential carrier side bearings or pinion bearings, but that is a different matter, altogether. In MOST cases, those bearings are a different series, with a different angle to the rollers and races.

I have yet to see a single manufacturer's instruction to pre-load a set of tapered roller bearing wheel bearings.

WHY are you complaining about the job the guys did on your trailer... have ANY of the bearings failed???

Don't know if I'm right or not, but I darned sure know what lasts and what doesn't.

Just one of the perks of being old. :>)

Allan

they want "0" perload on a tapered brg.

I havent yet seen a service manual that tells you to perload a tapered wheel brg

Without naming names, our buddy, "Me Thinks" is VERY well informed and is an absolute, killer, outstanding wrench. He is a very knowledgeable guy.

He and I have had this discussion before.

However, I would submit that manufactures are in the business of SELLING bearings and for darned sure not actually in the nature of prolonging their useful life.

Heck, what's a little oversight/misprint here and there in the old tech manual amongst friends?

Just a slight variation on the old “built in obsolescence” theme? You know, let's make ‘em go “Just long enough”?

Pretty slick marketing, I'd say.

Allan

Allan