I replaced the front wheel bearings, and the noise does not change a bit. The tires are good, btw. Noise seems to be from the front below, but I have ruled out the front wheels. I have changed rotor/hub, pads, and bearings for the front wheels. This is really frustrating....

 

I know exactly how you feel, some times it seems like you just keep throwing money at it and in time you'll have a new truck. I've looked at my shop manual and at this time I have no clue as to a fix. I wish I could help. I'll keep thinking on it and if a good thought occurs I'll pass it along.

 

Yeah, I'm hoping this will be resolved at some point. Its not nice to have a new truck but no food for a few months!

I still think its from the front. Is it possible for something that happens on the rear (like differential) to sound like from the front?

One last possibility is my calipers. I haven't really serviced calipers before, and they were pretty rusty. One of the caliper slide pins on the right side were sticking, I sand it a bit, clean it up, and put new grease. I'm not sure how smooth the caliper slide pins should be. Do you think this scraping noise could be caused by sticking calipers/caliper slides?

I was going to jack the rear wheels and let the engine run on rear jacks (its a RWD) and see if the noise happens as such, to rule out drivetrain problems, but has not gotten to it yet. Maybe when the drivetrain is ruled out I'll replace the front calipers and their brackets.

 

That's not a bad idea, just remember to use jack stands or bad things could happen. No need to replace the brackets as they are machined castings. The calipers could have a piston that is not fully retracting and that could be the cause of the whole problem.

It's very hard to do a good diagnosis long distance but I hope all this helps.

 

Wow, its actually the from the rear! From inside the vehicle it does sound very much from the front, but from outside its a different story! I put the rear axle on jack stands and run the car and sure thing the noise remains. So I let my wife hold the gas pedal as I listen for the noise, and it is coming from the rear-left brakes. The right brakes seem to make the same noise but it might be resonation from the left. It may be differential, so I put a screwdriver to the differential housing and there was no strong vibration felt. The vibration is stronger on the left rear wheel area, such as the spring suspension.

Its too late check the brakes now, maybe I'll do them in the morning.

 

Glad to hear that you have it pin pointed. Left rear axle bearing shouldn't be too hard or expensive. Good for you. let us know when it's fixed.

 

I removed both wheels and checked the brakes. The brakes are rusty, but seem to be working, still some life on the pads. I run the car again in gear without rear brakes, and noise is the same, so brakes are not the problem.

However upon closer inspection (without brakes), the noise is actually coming from the center differential. Just to be really sure, I crawled underneath and stuck my ear to it. Surely its coming from there. Its also accompanied with knocks, rumble and rattle, especially in higher gears (faster rotation). Is my differential busted?

Just to be sure as well, I crawled under the transmission and stuck my ear there as well, no strong vibrations/noises from there.

The vibration and noise is more noticeable when I hold the left axle (with my hands) than the right one. Thats why I was suspecting the brakes/bearing of that side. But the brakes are fine, and I don't hear any strong noise or vibration directly on the hub area. It may be the differential gear that connect to the left wheel is causing the vibration/noise.

Well I am both glad and sad. I'm glad I seem to find the source of the problem but I can't imagine myself servicing the differential. I guess I'll have to spend the big bucks to fix that.

 

Well I am both glad and sad. I'm glad I seem to find the source of the problem but I can't imagine myself servicing the differential. I guess I'll have to spend the big bucks to fix that.


When you get the cover off the dif. you will know if it's gears or just the bearings. If it's the side bearings it is a fairly easy job to change them. Just be certain to keep any of the bearing shims organized so they go back in the way thay came out. While you are in there you should rotate the pinion and see if those bearings are good.
It might be easier to just get a whole rear out of a donor truck from your local Pick n Pull yard. It will be cleaner and probably faster.
Good luck with it.

 

I was changing the brake pads and put everything back together. Just before I put the wheels I start the car again and put it in gear.

When I hold the left side leaf spring with my hand, I could feel the vibration pretty clearly. However if I hold the right side leaf spring, I could barely feel the vibration. The noise still seem to be louder when I hear it from the left wheel well. I'm not sure now. Could it be that its just the left side wheel bearing and the noise/vibration resonate to the center differential?

The vibration feel (with hands) seem to be about equal, the left side leaf spring and the differential cover. Maybe one is lesser than the other but I'm not sure. But my theory is, if the vibration source is the center differential, would it resonate equally between right axle and left axle?

Sorry I'm imagining things. I don't have time yet to open up the bearings. I'm just hoping its not a hard/expensive fix and I could drive the car longer.

I'm not sure if I'm that advanced to break into the differential. But if thats the way to go I may as well do it.

Is it common for this car to have differential problems? The car have 83000 miles.

Thanks!

 

I just read that to service the wheel bearings I have to open up the differential anyway... well... maybe next week...

 

If you have the time you should pull the rear cover off and check if the gears are bad. If they are my suggestion was to get a whole rear from the bone yard and if you decide to do that you might want to get one from a 97-98 V 8 'sploder as they have a better gear set 3.73 and I think they all have a traction lock diff. It would be a nice upgrade for your truck.

 

so I pulled off the differential cover; the ring gear and pinion seem to be ok, but I ain't a mechanic. Looked nice and smooth. No metal pieces in the oil.

I visual checked the wheel bearings. Looked ok. Just to be sure, I pulled out both axles and run the car in gear. The noise is still there! So it should be something in the differential. Maybe bearings.

I heard that servicing differential require intricate settings that is better left to a professional, is that so?

I probably be heading to a boneyard soon...

 

Setting up a rear end should be left to the pros. I think I'd check out the nearest Pick n Pull for a rear. I think the price would be about $75/100 taking everything, rotors, calipers and all. Look for a Clunker as they had to drive to the dealer and be road worthy and then the only thing they ruined was the engine.

 

How do I check if the differential in the junked car is in good condition? I mean, my differential looked great but its busted.


Also I noticed something else. Previously my explorer used to make occasional grinding noise that vibrates the hole car when starting from stop in 1st gear. I was thinking that its because the clutch chatter (clutch getting thin). However since I drained the differential oil and put new gear oil, this does not happen anymore. That differential might be due for oil change or something. The car also has more noticeable jerks/stutters when accelerating around 30-40 mph in relation to the noise until it smooth out around 50 mph up.

 

About all you can do is find the best looking wreck or clunker in the yard and take a chance. It will most likely be a good one. If you change the wheel and axle bearings and yours is still bad you will be forced to take the truck to a shop top replace the bearings in the dif. to protect the money already invested.