Drivetrain whine like it's going out of style
 

I have this whine coming from somewhere in the drivetrain (mid to rear of the car). It has progressively gotten louder since last year. It only whines when I let off the gas, and seems to be loudest when I let off the gas at higher RPM's. I swear it's coming from somewhere mid to rear of the car. I doubt it's the tranny, it was rebuilt by Shep about 40k miles ago. I'm thinking t-case but I'm not sure.

The t-case was leaking a little fluid at one point but that stopped. Fluid level was fine and I topped it off just in case a while back. I had actually taken it to the dealer to see if I qualified for the t-case recall about a year or two ago when I noticed some drips from the t-case on the garage floor, but they said doesn't qualify and wouldn't budge. I don't want the rear end or the t-case to lock up on my while driving.

Has anyone dealt with this? Any simple checks I can do before I have to actually remove and inspect the t-case and/or rear end?

Re: Drivetrain whine like it's going out of style
 

Check/swap out your rear end fluid. It may or may not be your issue, but it's probably never been changed. Hit me up on IM.

Re: Drivetrain whine like it's going out of style
 

I'd change the fluid of the transfer case and rear end and see what happens.

Re: Drivetrain whine like it's going out of style
 

If the rear diff fluid doesn't take care of it, it's a worn pinion gear.

Re: Drivetrain whine like it's going out of style
 

You might want to check that out pretty fast. I've heard of people having their rear end locking up going highway speeds not to long after neglecting that whine.

Re: Drivetrain whine like it's going out of style
 

BTW, do you have any spots/leaks on your garage floor? Take a quick look under the car at the rear end to see if you can spot any wetness or signs of leaking at any point in the past.

Re: Drivetrain whine like it's going out of style
 

That was my first thought. Not the cheapest rebuild if yours is anything like the Evos.

Re: Drivetrain whine like it's going out of style
 

I'm going to replace the fluid in both the rear diff and t-case Saturday morning, hopefully that resolves it.

Mo: no leaks on the floor as far as I can tell near the rear of the car, but haven't looked close underneath for wetness or drips.

Re: Drivetrain whine like it's going out of style
 

Any luck?

Re: Drivetrain whine like it's going out of style
 

No, I haven't had time to check anything. I noticed another thing though - the whine seems to only happen during deceleration, while in a gear... which kind of makes me think it might actually be clutch/tranny/t-case.

Re: Drivetrain whine like it's going out of style
 

I believe I figured out what it is - I went to a mechanic that I trust and he showed me that the driveshaft has play in it, like 3/8 of an inch of play when I rotate it by hand near the rear end. So it is in fact a worn pinion gear and I need to rebuild my rear end or buy one.. fun. Thanks for the help

Re: Drivetrain whine like it's going out of style
 

Rear end: either the pinion or ring gear, transfer case, center diff lower housing/3rd gear in the tranny.

~John