Hi,i've got a 1990 Full size and have a noise coming from the left front wheel,or under the drivers side left front.it mainly occurs when applying the brakes and sounds like a grinding noise but it seems like a surge.It makes the noise after applying the brakes and does not increase with speed.It I pulled off the wheel,inspected the caliper and it is fine as well as plenty of life on the brake pad.I have newer manual hubs that are a little over a year old and pulled it off and removed the internal components of the hub.Every component upon inspection operates and appears fine.I did notice that the hub end was a little hot when I pulled off the wheel.This noise was at first not as loud when I first heard it and is getting increasingly louder over 7 months.I thought it might be the u joint in the axle and they are tight.I also checked the upper and lower ball joints and they are fine.I pulled the tire and notices about 1/4 to 1/2 of play when pulling from each side of the tire.I drive a semi and it is a second nature to be able to accurately identify and be able to describe a mechanical issue for the mechanics.Any help appreciated.

 

Sounds like a wheel bearing. With the side to side movement it's either that or a tie rod end. I can't see a tie rod end making that kind of noise. The heating up points to friction and probably the bearings.

 

I would have to agree w/ JMCF, sounds like a wheel bearing. I f you do R/R them make sure you do both of them on each side. If you have all ready taken the hubs off before, getting to the bearings should be a piece of cake. Good luck!

 

i triple that suggestion Bearing

 

Not ot be a Blockhead but I see you wrote "brake pad" as in one. I have had problems with front calipers on all my Broncos and the inner pad wears far faster than the outer when the caliper starts to stick. I personally don't see why you would have a wheel bearing problem only under braking(sorry guys). I have seen wheel bearing "clunk" under braking.

 

It's the side to side movement and heating that make me think wheel bearings. I just figured he meant pads. Although I did have a pad seperate from the backing plate one time...that called for a rotor replacement.

 

if it is the bearings and you do replace them yourself be sure to put them in right and since you have it that far apart you better check the axel bearings too

 

Yeah,I figured that with 104,000 on the original bearings on the front,it wouldn't hurt to pull apart and inspect the wheel assembley.I replaced with new bearings and am having a hard time finding out what specs to torque them.Plenty of life in the pads themselves and I noticed only one retainer clip on the bottom of the inner pads on the inner for each side.I went to Auto Zone and tried to find out how much for a new front axle bearing (inside the spindle) and they didn't even have a part # for it.Has anyone heard of these going bad or is it more the actual pair of wheel bearings?Thanks much

 

Napa has them

 

I hate napa.
The prices are way too high

 

The bearings inside the spindle are for the axle stub shaft, which only rotates if the hub is locked OR if you're in 4WD OR both. Yes, they often go bad, but you wouldn't hear them normally since they're not turning.

For your '90, I think you torque the inner nut to ~50 lb-ft, back off ~90 °, set the locking ring on the peg, then torque the outer to ~150 lb-ft.