Warm Nuts

[Jim_Phillips]

I fitted new brake discs last week end. I struggled to get the preload right on the wheel bearings and have been worried that they may be over tight. Just as a precaution I have been checking to see if the wheel hubs are warm at the end of a drive. Mine seem to be - even after 15-20 minutes, my wheel nuts are warm. It may of course be heat generated from the brake disc. But being paranoid, I am worried it could also be from the bearings being too tight. Any opinions?

 

[Doc]

It's more probobly from brake pad drag than friction generated in the bearings.

The only way to know for sure is to pull that cap off again and check the races for blueing.

 

[Jim_Phillips]

Thanks Doc - think I will have to do that. Do you think new grease in the bearings creates extra friction that throws the scales out for the prepoad measure? My feeling is that compared to diff oil (which was all that was in there before I changed the inner axle seal) grease must (as its less viscous) create more friction...

 

[swank60]

You know, if you think there's heat build up coming from this disks, it seems like you could drip a little water on the disks after running for a while and see if you get any steam. If not, try it by touch - check further away from the hub just in case, though I doubt it would transfer that much heat...with the lugs being warm, I'd put my money on the preload issue.

I'm not sure about grease creating more friction overall - yes it would create more compaired to dif oil, but there's better protection on your metal to metal surfaces, where the real friction would occur.

If your gut is telling you to recheck that preload, I'd say go ahead and check it out. Better safe than sorry.

 

[Jman]

Whenever I had disks that were rubbing enough to cause heat, I could smell them (unmistakeable smell). Next time you drive, do the sniff test.

 

[billybob_98]

ok here's a question. my front axle is way f/u. po had all maint. records and took excellent care of it, but the knuckles leaked when i bought it. i replaced the outer knuckle seals and the bearings and such inside the hub, about a year and a half after purchasing. i was broke and in college. plus with cold winter mud on her, she was a bitch to work on. and so my hubs were always hot. lug nuts too. i think they cooled down after the replacement, but they are shot to s*** again. i think my axle oil is getting into the knuckle grease, but what is the most effective way to replace, the seals and bearings to get a like new set up so i don't have to take the axle apart every year. also the driver wheel hop or death wobble. it's been addressed before but i can't recallect what the solution was. any answers. thanks ben

 

[lovetoski]

JimPhillips - there is a procedure in the FSM on adjusting the front hubs. It's important to follow it exactly - then you'll not worry about if you got it right. You can use a lightweight fish scale to check pre-load on the front bearing.

Regarding temp of the front hubs, from a discussion on the 80 forum, consensus is that braking can cause the hubs to heat up quickly. If you coast to a stop though (maybe using the e-brake at the end) then OK. You should be able to put your hand on the hub for a few seconds w/out causing any damage...

One more thought on the brake thing - a dragging brake can make a big difference. When you recheck the bearings, make sure you have the pads pushed back, or the caliper removed.

If it helps, I've messed this up a few times!

Good luck.

 

[lovetoski]

Billybob,

You have a bunck of potential problems in your post...lets see if I can help a bit:

Front wheel death hop - this could be as simple as an out of balence tire. Get it checked for starters. If the wheels/tires are balenced OK, then you have some suspension wear. Things to check include ALL of the following: wheel bearings, knuckle bearings, tie-rod ends, drag-links, steering gear box, shocks, u-joints, and misc bolts (knuckle bearing bolts, u-bolts, esp). Best way to check these is to jack up the truck, take off the wheels, and start checking one by one.

Front axle stuff. Check the condition of your diff oil. If it's yellow or brown, you might be OK. If it's thick, goopy, green or grey, or especially if it's "sludgy" then you have a leaking oil seal. Also check the grease in the knuckle - stick a q-tip or similar into the knuckle housing fill port (square head cap). If it's not "grease" but something gross, you've got a failed oil seal.

If the oil seal is failed, you should rebuild the front axle. If it's been 60,000 miles or more since this has been done, then it's time anyway.

If the oil seal has not failed, then perhaps it's just a wheel bearing adjustment. Given what you've said, at minimum I would repack the wheel bearings. (I'd also do the diagnostic stuff on your front suspension.)

Best Regards,

 

[Doc]

Billybob, sounds like it's time for a front axle re-build. Contact C-dan and get all the needed bearings, seals and gaskets. Take a weekend and do it. Most likely that inner oil seal needs to be replaced, too bad it's the last piece to come out of the axle, and the first to go in!

 

[Landpimp]

DONT touch the rotor to check the temp..........I have one finger missing any prints

Jim, I have never used a scale to do the wheel bearing preload, I just adjust untill or just a hair pass) the wobble(@12 and 6) is gone.......and that where I set it. Its easy to double check again(like after a day or so), if too loose you can tighten in just a few minutes with the wheels still on. Been doing this for 7 years without issue.

 

[Jim_Phillips]

I checked my preload this weekend and everything seemed fine. I think the heat must be coming from the brakes.

I'm with you Landpimp on the adjustment - fish scales are good for weighing fish but I don't find them great for measuring preload. I tighten just enough to take out the wobble.