jc46002003

Hello Mustang Friends,

I have a story and question for this community.

I bought a 2014 Mustang GT( 6r80 auto ) 'new' about 4 months ago. It had 200 miles on it when I bought it. Drove it home the day I bought it, no issues found as I drove fairly conservatively. Next day, I went to work and as I came up to my exit and I let my foot off the gas to slow down then BOOM, felt a vibration, kind of like a tire was out of balance. Except I knew it wasn't a tire because my tires are fine in every other situation. If you throw the transmission into neutral the vibration goes away. The vibration can only be felt while decelerating from any speed above 40 MPH. We replaced the drive shaft already, no change.

Another issue is that it appears that my limited slip isn't working very well. On slow starts, the passenger side tire breaks loose pretty easily. And if you turn the moment you start off, you feel a grinding feeling in the seat like the torque converter is slipping except it's from the rear of the car. There's also a humming noise coming from the drive line around 64-68 MPH. I suspect it's coming from the ring gear in the rear differential. Right now, ford is ordering a ring and pinion and advised me the rear needs to be 're-shimmed'. They told me today that the ring and pinion won't be available until about 30 days from now.

So to sum up:

Decel vibration:
happens when letting foot off the gas above 40 MPH
can feel it in the steering wheel slightly and in the seat
can hear the drone from the vibration audibly
sounds like it's coming from the back end of the car
goes away when tranny moved to neutral
drive shaft replaced - no change

rear:
limited slip not working
drive line noise from 64-68MPH
ring and pinion on order

My question to the community is, can my decel vibration be related to my rear end issues? I hope so because if not, that's gunna be a bugger to troubleshoot.

Anyone have the same issue or have any troubleshooting hope you can give me?