Loud grinding sound at 30-40 mph

[Mike777]

Hi. I have an 02 XLT and heard a loud grinding sound two days ago when I drove between 30-40 mph. A mechanic told me it is the differential, and they will probably have to replace the whole part. He also said I need new wheel bearing in the left rear. Total cost around $1800.

I dont really want to pay that much money, and I don't really trust he knows what he talking about. Anyways, I was driving this morning and the car drove fine with no sound.

Any ideas what the problem could be??

 

[ranger-93]

Theres a lot of info floating around on this forum but a little more info would probably help.

Where did the grinding noise come from? (front,rear,etc.)
How often do you hear?
Once you hear it how long does it keep making the noise?
Can you turn, speed up,etc. and reproduce the noise whenever or is it random?

These will help others help you.

 

[Mike777]

Reply

The noise sounds like it's coming from the front drivers side. The noise is constant between 30-40 mph. Or when I go over 40 mph and slow down and am in the 40-30 mph range, it starts again. It only started 2 days ago, and this morning there was no noise and the car ran like usual.

Thanks

 

[ranger-93]

Im not to familiar with that year ex but its AWD correct? I dont know if thats common to happen or not, but a ring and pinion will have a "roar" once up to speed if somehow they got out of specs. It is possible that it could be a wheel bearing, which on your ex (if Im not mistaken) needs a whole new hub because it has a sealed bearing. Another possibility it could be would be a carrier bearing in the differential. I dont think theres a way to really check the carrier bearing with a tear down (at least not that Im aware anyway). But you could check your wheel bearing to see if that's the problem. Theres many "how to" threads here. The search button is your friend.

 

[Mike777]

re

Thanks for the response. It is 4x4. I drove it again this morning and the loud grinding sound has gone away, but i can still feel a very slight grinding. If I wasn't looking for it, I probably wouldn't even notice it, but I figure if it is (or will be a problem), I might as well take care of it now. Could something like this simply be a result of low differential oil?

Thanks

 

[ranger-93]

If it is 4x4 no because the front diff wouldn't turn in 2wd but if it is AWD which is different from 4x4 its a possibilty and wont hurt to check.

 

[jakedrew]

I bet it is a wheel bearing.

Dont let that guy fool you into a rear end replacement . ( them just Howl when you give it a little gas @ 50 ish mph and the howling goes away when you let off)


Jack up the vehicle and see if the tire has any play in it.

 

[Mike777]

Thanks for the response. While driving today it felt as I had a flat tire. I took it to another mechanic and we took it for a ride and he thinks it's the transmission going. Most likely I'm going to have to rebuild it.