Rear end grind, but no whine

[scotty7676]

Hey all, I just picked up a used '04 XLS with 51,000 miles. I have searched the threads for rear end noises and all I see are rear end whine issues which seem common. But mine doesn't whine at all, just has this grinding sound when going around turns. So say, you do a u-turn, it makes this grinding sound from the rear end...the more gas you give it, this more noticable the noise/feeling. Any ideas what this could be? You would almost think it has a limited slip (I don't know if it does) that is trying to lock up, the way it feels.

Any feedback would be appreciated!

Thanks,
Scott

 

[Donner]

Same thing here...

I have an 03 xlt, but last night I started it up, no problems. Drove 5 miles, sat for 45 minutes, started it up again and about 5 seconds later a grinding noise seemed to come from directly beneath the passenger cabin area... it only lasted two seconds or so, but I'd never heard that before. I don't know what's down there... so I'll wait to see if it's the same type of issue. My vehicle was not in motion at the time, just had the engine running.

 

[rrgone]

Scott - My guess is wheel bearings not rear end. However, have you checked fluid level in the diff?

Donner - ??? Maybe it engaged/disengaged the 4X4? Have you had any problems with the 4X4 working?

 

[Donner]

4x4? I'll check it out...

Scott - My guess is wheel bearings not rear end. However, have you checked fluid level in the diff?

Donner - ??? Maybe it engaged/disengaged the 4X4? Have you had any problems with the 4X4 working?

Dang! How did you know that?? I used 4x4hi twice in the last 30 days just for a few minutes to crawl through a dirt gully... But I go up some pretty steep asphalt inclines back here in the hills regularly. One in particular is very steep, and I never heard this sound before going there. Also, from time to time, I will switch (parked in neutral) to 4x4low just to listen for engagement...
(by engagement I mean what I hear from the cabin, never paid attention to the exterior or undercarriage sounds... ) Do you suggest I go through 4x4hi and low to listen for that?

 

[Donner]

Interesting...

Scott - My guess is wheel bearings not rear end. However, have you checked fluid level in the diff?

Donner - ??? Maybe it engaged/disengaged the 4X4? Have you had any problems with the 4X4 working?

I went outside and left the vehicle in neutral while I changed through 4x levels... the first time I did the 4xlow, it made a ping sound. I went through it about 6 or so times, and it made the ping sound twice (only in 4xlow) It made no sounds in 4xhi, just regular shifting of the display light.

 

[rrgone]

I went outside and left the vehicle in neutral while I changed through 4x levels... the first time I did the 4xlow, it made a ping sound. I went through it about 6 or so times, and it made the ping sound twice (only in 4xlow) It made no sounds in 4xhi, just regular shifting of the display light.

Sounds like your 4X4 system is working fine. I thought that maybe you heard the shift motor engage and disengage. I don't know what else it could be if the vehicle wasn't moving.

 

[Donner]

Thank you!

That is likely the situation... very good observation, and to think, when I take it in for service no one has ever asked that question. This is my first automatic and first 4x, so the sounds are still new to me (even though I've had this vehicle since 03). Thank you again!

 

[scotty7676]

Thanks for the response. I do need to check the diff fluid, but I don't think it's the wheel bearings though because it doesn't make the noise when cruising or going around a corner while moving. Only when taking off and turning from a stop. I'll check my diff fluid this week and report back.

Thanks

 

[Explorer_gal]

Thanks for the response. I do need to check the diff fluid, but I don't think it's the wheel bearings though because it doesn't make the noise when cruising or going around a corner while moving. Only when taking off and turning from a stop. I'll check my diff fluid this week and report back.

Thanks

Hi scotty7676
I think you'll find that your differential fluid even if it's not low may need changing. I went through the exact same problem that you described last winter. My diff fluid wasn't low but extremely dirty so I had it changed.I do have the limited slip rear end and it turns out it had the wrong grade oil in it and was missing the anitislip oil additive right from the factory. After I had the fluid changed within about three days the grinding that I experienced while making slow speed turns went away completely. Perhaps this is whats wrong with your truck... Good Luck !

 

[IZwack]

Ah the limited slip chatter from the lack or breakdown of the fluid additive -- good catch Explorer_gal

 

[scotty7676]

Yes, that is a good idea. With 50,000+ miles, I might as well go ahead and change the fluid no matter what. I just traced down a brake issue today, so I will try and get the fluid changed this weekend. I may just get the synthetic Mobil 1 with the friction modifier added, and see how that works.

Thanks!

 

[edd189]

Scotty, did changing the fluid stop the grind? Mine is doing same thing. Think I may have gotten water in it putting a boat in this weekend...

 

[scotty7676]

Nope, it's still there, it didn't help. It's been almost 2 years now and hasn't gotten any worse either.