Loud Droning Whine?
 

Ive got a loud whiny noise that seems to be coming from the back of my car. I have Torque Solutions Rear Diff bushings and heard a drone after the install but searched EvoM and seemed normal, but it has gotten louder after a long drive. Looked at the rear diff and there is def some oil on it, more than normal. Any way I can check it? Thanks :mitsu:

Put the car on the list is the only true way to check it from underneath sound can travel underneath the car. After my car got its transfercase rebuilt by people I rather not say who but never again.

The sound of the tcase has alot of harmonic that travel underneath the car past the driveshaft to the back of the car so keep that in mind. Be sure to use the car stethescope to pin-point where the noise is coming from while the car is in the air just be careful under there.

Is the noise only while you are moving or all the time?

If it is all the time, including while stationery, have a quick read through this thread.

https://www.evolutionm.net/forums/ev...nows-what.html

Only while Im moving and seems to be the worst between 65-75 at about 1/4 throttle cruising.

My best guess would be sound from your TC. I had a high pitched whine that would peak at about 80mph. My TC was previously rebuilt by shep, so I sent it back and I had damaged the ring and pinion. Got the new stage 2 upgrade and the car is absolutely quiet. I can actually hear my fuel pump again.

My mustache bar mounts are hard mount and rear diff are upgraded poly.

This kinda just happened, and I wasn't beating on my car. I'm not sure its the TC, it def sounds like its coming from the back. I'm gonna drain the rear diff today and see what it looks like but I feel like it gonna be full of shredded metal...

what fluid were you running the rear diff?

DiaQueen, like im supposed to

There is tons of posts about rear diff bushings making noise around 70mph, my guess is the bushings.

I noticed that when I did the install, but it was considerably louder than usual on the way back from Knoxville...

Just pulled the drain plug, there was no fluid in it, metal on the plug which looks bent? Im sure its toast now, but i dont see how it happened.

Which one the rear diff or the tcase? If it was the tcase one or more of the 3 seals prolly went out and the tcase bled out.

Rear diff

was able to get under the car and there is a ring where the driveshaft comes into the diff that looks unseated/loose. Looks like this came apart and threw all my fluid out? Any ideas?

^ that's your problem. I installed my rear diff bushings then got on the highway for a 4 hour drive. It's a horrible whine that sounds like something is broken, but i was told its normal.