Hi all, i have a 2000 SLT 4X4 4.7, i get this faint whining noise when i let off the gas, ( when am coasting) i checked the fluid levels and all seem to be right.

Really not sure if front or back, sounds more in the back, i did a fluid change about 4 years ago when i replaced U-joints.

Any thoughts???/

 

Im assuming you mean the diff oil level was checked has the cover plate ever been removed and checked and cleaned up. Some diff's need an additive the limited slip. The older diff's the 8.25 oil level is at the top of the hole and a little more if you can park the car with the passenger side higher so you can get more in it.

When I was a little low my rear whined very lightly

 

Sounds good will recheck the levels again just to make sure

Thanks

 

Wouldn't hurt to do another fluid change. If it's been 4 years ago you have put somewhere between 40 & 45,000 or more on it since.Gear oil just like any oil will break down and not be as effective over time.While you have the cover off take a real good look in there for any damage.

 

Tks all, will put on list to get done next month, onca again for for your comments

 

Thanks for all the help,, i checked the transfer case and it was a half quart low. got it topped off now.. still have to do a test drive..

Eric

 

Al right did a good test drive and did not make a differance, am out of thoughts on what it can be. I checked all fluid levels, u joints, everything seems to be right. Maybe i did not explain whats going on right. i do that that all the time. maybe this will help. when i let off the gas to coast it slows down more and can here a whinnying noise like it in a lower gear, the rpm's seem normal. Any thoughts...

 

How agressive are your tire threads it just may be your tires are the noisy kind

 

Really not thinking so but a good thought, running just a good highway tire right now. this noise happened way after i put tires on it, and still in great shape

 

It could also be wear or damage in the differential. Pull the cover and inspect the ring gear for starters. Any change in backlash, or damage to the teeth, can cause noise.