wheel bearing?4x4 | Ford Explorer Forums - Serious Explorations

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wheel bearing?4x4


New Member
January 11, 2012
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Year, Model & Trim Level
1991 Ford Explorer
I have a 96 explorer xlt just replaced the hub/bearings,the right one was really bad.My question is now that it is back together the 4 wheel drive feels like its messed up and not working and i have a humming vibration noise when I'm driving,If i put it in neutral it goes away,if I engage the 4 wheel drive and try driving and put in neutral the noise stays until I disengage the 4 wheel drive,but comes back as soon as I put in gear.

so could the bad bearing messed up the transfer case or the cv shafts?upper and lower ball joints and tie rods are sorta new.before the bearing went out the 4 wheel drive worked with no problems and there was only bearing noise.

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How long did you drive with the bad bearings?

the right one was the one that really messed up,but It was only starting to make some noise(like a slight hum) so I drove on it for about 2 or 3 months(trying to save up for them and still go to work)It starting getting really bad so I replaced them.

Did you change the races when you changed the bearings? What brand of bearing did you use? It does make a difference. When the Timiken rep comes to our shop, he stresses that you have to use the new races when using their bearings. Just want to rule out the races as the culprit.

On a 2nd gen 4wd it is a sealed unit, so races were replaced. It is fairly likely that it is tire noise

but if its tire noise,why does my front transfer case make a ton of noise when in 4 wheel drive but not in 2 wheel?it only make a slight humming/vibration in two wheel,I'm starting to think its the front transfer case cause its worse with it locked in.
And yes they are sealed complete hub/bearings,not press in ones.

You said there is noise when driving in 4wd that goes away when switched to 2wd. Where are you driving with 4wd engaged? If you are on a road with dry pavement, that would be absolutely normal. 4wd is not for on-road use. If it is working properly, you will get a lot of road noise and binding with even slight turns because your axles are all locked.

By front transfer case, do you mean your differential? If it makes a hum on the road with 2wd, and worse in 4wd (on the road or off road?), it could be a few things.

Do you have any idea when the front and rear diffs had the fluid changed? What's your current mileage? Also, have you ever forded water deeper than your axles?

A very low hum doesn't necessarily indicate a problem. All gears make noise as they turn, especially when they're old. First, run your explorer for a few minutes on the road to mix up the diff oil and get it a little warm. If you can, engage 4 high before parking it. Then, pull the front diff fill plug and check your fluid level. Should be filled up to just a little bit under the fill plug. If that's good, and if the fluid you pull away doesn't have visible debris or metal flakes, you may have to dig a little deeper.

Tighten your fill plug back up, then jack up the front and rear so all the wheels are off the ground. Lower it onto your jackstands. Put your trans in neutral and lay down under your front diff. Spin the front driveshaft by hand and try to find exactly where the noise is coming from.

Let me know, and I'll see if I can get back to this thread soon.