Constant gear whine in every gear but 5th. That was very annoying, even if the transmission oil reports came back OK.
Had unbearable noise from rear end. Dealer change out pinion bearings and axle bearings under drive train 50K/5yr warranty for my 2012 GT.
8.8 rear end with 3:31 gears, had SECOND pinion bearing go out (replaced once already) causing severe rear end whine at 60+ mph. Repaired under drivetrain warranty.
Had the rear axle vent breather replaced via a TSB for the 2011-14 Mustang GTs. Rear axle vent breather nipple leaks significant amount of gear oil onto axle. Dealer replaced with TSB hose and catch-can for rear axle vent.
2nd and 3rd gear synchronizers replaced.
Vent valve on rear axle leaking differential fluid. Fluid found on drivers side axle and differential housing. Repaired under TSB 12-8-15. Dealer added adhesive to threads on vent valve and checked fluid level.
Transmission difficult to shift into 2nd and/or grinding. Most noticeable for the first few minutes after a cold start, and on days when the ambient temperature was low. Dealer replaced transmission fluid with updated fluid per TSB.
Transmission became diffucult to shift, sometimes not going into gear. Dealership replaced transmission fluid as per a ford tsb. Shifting is better but not great like when new. Transmission noticeably noisier after fluid swap also.
I noticed a stain on the rear end & axle. Repair wa replacement of the final drive/differential vent assembly.
The rear end/final drive leaked again. Replaced seals. Still a problem. Currently back in shop.
Essentially all internals for the rear differential were replaced. I have reason to believe (but cannot prove) the dealership techs improperly reassembled the differential while attempting the previous repair.
Hard shift into 2nd gear. First attempt was a fluid replacement as there was a TSB that recommended a lighter fluid. That did not resolve issue so they replaced the transmission with a new part.
this was a reoccurring speed sensitive squeak from drivers rear axle. The shop greased caliper 1x I greased 1x but came back Shop replaced bent axle under wtty partially because I keep friendly with my sales person. I diagnosed for them.
Manual transmission grinds on cold days going from 1st to 2nd gear. Had taken it to dealer in Jan and they said all was fine. Gave them the Technical Service Bulletin this time (thanks TrueDelta). Covered under warranty.