Hey guys,

My 2013 mustang gt has a pulsating/wobble sound coming from the rear when deccelerating around 40mph and also around 70mph. It only happens when i am deccelerating while in gear (doesn't matter which gear i'm in) around the mph i listed. No noise is present when deccelerating while in neutral. Now i heard that it could be a loose pinion gear preload but i'm not sure. Im about to pull the car in the garage and take a look. Any help would be appreciated. Thanks!

 

Is the car lowered, how do the upper and lower control arm bushings look? A change in the drive shaft angle as it enters the rear diff can put stress on pinion seal and bearing. If the angle isn't correct, over time it can prematurely wear out the seal and or bearing.

 

Mine does the same thing I think, kind of an oscillating growl/vibration every 1-2 seconds@45 mph? I've been tracking this for a while.

My stock 3.31 axle did this at highway speeds on decel/coast in gear. I swapped axles for a gear upgrade and that one was worse, had vibration issues and whatnot. Took my aluminum driveshaft out 5 times or so trying to see what it was, flipping it to see if the balance would cancel it out. Still there with a stock shaft. Ended up changing out the gearset for another 3.73 new set to get rid of gear whine (bad setup, backlash and preload was off by a lot). The vibration got a lot better and the gear whine is gone (whoot, first gear install!) but it is still there, just bareable at this point. Im still running the stock driveshaft.

Given that I had this on the stock axle I've basically given up. I am running stock control arms, boss 302 springs (stock ride height) and a stock driveshaft. So its definitely not something suspension related.

 

Had a similar problem, noise was slightly different but took it into dealership and found out my bearings were going out

 

Yup never taking my car to a stealership again, they suck. Wanted to charge me 1200 to rebuild the rear end, $450 of that was just the gear set. Anyway I just replaced the bearings, with the exception of 1 axle/wheel bearing and the noise is still there.