Wheel bearings constantly loosening

[ascuro]

So far this is the most serious problem I've encountered with my blazer - several weeks ago, I replaced the extremely worn front wheel bearings and seals (along with all four ball joints).

Since then, they keep loosening up no matter what I'm doing (offroad, onroad, etc.) The first time I noticed it, I could move the tires a good half-inch - and yes, it was quite scary driving like that, hehe.

I'm installing/tightening the locknuts following the procedure in Haynes (70 Blazer, dana44 - 50ft-lbs, back off 90 deg, 35ft-lbs, back off 3/8...then lock ring...then outer nut to 50ft-lbs). I've seen a few articles/walkthroughs around that say to just tighten the inner nut to 50ft-lbs and back it off 1/4, but I'm hesitant to try that out since it feels way too tight (lots of resistance/roughness when turning the axle like that).

I had the old races pressed out and the new ones pressed in by a shop, so I'm pretty sure they're not at fault...any theories? Crappy bearings maybe? It happens on both sides just as much though.

As somewhat of a plus though, I've become extremely efficient at stripping down my axles...done it four or five times now...both sides

 

[k20]

my gm manual shows the outer lock nut to 160ftlbs. Also are you sure your aligning that pin up w/ the locking nut correctly? Its a pita to get the pin in one of the holes.

 

[1-ton]

Also are you sure your aligning that pin up w/ the locking nut correctly? Its a pita to get the pin in one of the holes.

I agree. Make sure the inner spindle nut does not have the little lock pin sheared off, and that you are putting the inner spindle nut, lock pin, washer (the thick washer with all the little holes) in between the inner spindle nut, and the outer spindle nut.

 

[hack500]

I sheared that little pin on the lock nut the first time I replaced the u-joints on my old burb and it loosened up. then after pulling it back apart to fix the loose bearings my buddy noticed the pin and then I realized

 

[ascuro]

Yeah, I'm sure I'm aligning the lock pin...it's the most frustrating part of each rebuild, hehe. My pins are both fine, as are the tabbed washers.

Does anyone have different tightening/adjustment specs for the inner locknut though? I really don't see how the nut can actually be loosening up with the washers locking them in place...I'm guessing I'm just adjusting the inner nut incorrectly.

 

[1-ton]

Next thing you could check is to see if the bearing races are completly seated into the hub.

 

[diesel4me]

mmmmmmmm......

The reason for tightening the inner nut to 50 ft lbs with the wheel turning is to fully seat the "cups" or outer races of the bearings in the hub completely,in case they were in a bit cockeyed..but if you had them pressed in at a shop,they should have been seated already..

Only other things that could cause them to loosen other than whats already been suggested is the hub might be oversized where the outer races go in,like if one had spun in the hub previously..I had one that way on my 74 K20,I had to use shim stock to get the bearing race tighter..it eventually needed to be replaced,I didn't trust it jerry rigged with shim stock,despite the machine shop saying it would hold up ok..I had a heavy 8' plow on it,didn't want my wheels falling off at 65 mph!..

Another thing is maybe the inner grease seals are tight fits to the sealing surface,and fool you into thinking the bearing is adjusted tight enough,when in fact its just the drag of the seal your feeling..mixing old cups with new inner races can cause rapid wear and loosening too..

 

[yzman_bad250]

Hi i jus joined,Great site, my wheel bearings keep doin that so i torque them at 40 and they been good ever since

 

[blazin_blazer]

spun race

i spun my outer race once ...i just took a small center punch and made a row of 3 around the hub then locktite and pressed the race bake in let it sit over nite...i never had no trouble again...now next person who owned it may have had a tough time removing it....i also always swap my bearings..take your old 1's to a industial bearing house and they ussually can swap the #'s or take measurements and get you timken bearings to go back in your truck they last alot longer than the 1's you buy from the auto parts store, especially if you clean and repack reguraly

 

[driney]

Are you turning the rotor as you torque the locknut? I've found that after I torque to 50 ft/lbs if I turn the rotor a few times, I can usually tighten it more. I keep doing that until the torque reading doesn't change, then back the nut off, retorque to 35 ft/lbs, back off about 3/8. I think it takes some effort to push the extra grease out of the bearing and turning the rotor seems to do that. Also when you find your bearings loose, is the outer locknut loosened? If it is, I would suspect that you're not getting it tight enough.

 

[RustyParts]

Are the tabs on the lockrings that slide into the machined slot on the spindle still in good shape? I had one that that was worn slightly that wouldn't stay in place.

 

[miniwally]

Adjust the wheel bearing preload however you feel is the best way. Everybody does it different.
The outer locknut torque is the important step here. The left side actually tries to loosen the inner nut ane the right side tightens it. The 160ft-lbs is what it takes to keep the left side tight.

Desert racers have had enough trouble with this that most now put left hand threads on the left side and right hand threads on the right sid eof all bearing nuts.