[Sidewalk]

The only noise inside my Fiesta is tire road noise. Totally quiet inside as I would expect from a modern car.

 

[Fabulozzz]

Bump, anyone else have this problem? Back at dealer to get this resolved once and for all, and now dealer say it's all normal...

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Salut JPROY12!
I have the same issue and have an appointment at my Ford Dealer in Montreal next week. 2014 Fiesta SE 5 speed. Transmission whines at highway speeds over 100km/h. Also whines in neutral with clutch engaged.

 

[Fabulozzz]

my Ford dealer is rebuilding my 5 speed gearbox under warranty. Transmission is in pieces on the workbench and parts have been ordered. So far i am happy. Can't wait to drive it again. I should get the car back tuesday.

 

[GabrielBSee]

Any explanation for this? I recently had a trans leak at the back-up light switch. Lost a decent amount of trans fluid. During this I started to get the whine in 5th gear, exactly as described earlier in the thread. I've since stopped the leak and topped off the fluid but whine still persists. Trying to get a definitive explanation to determine next steps.

 

[Paulm]

The sound that you hear could be from a misaligned carrier bearing. This is the bearing that helps support the CV axle on the passenger side of the car. I purchased my Fiesta new and it did not have this sound until after my throwout bearing was replaced (actually, after the throwout bearing was replaced a second time). During the replacement of a throwout bearing assembly, both of the CV axles are removed so that the transaxle can be removed from the car and then reinstalled after the transaxle is bolted back onto the engine. Because the dealer damaged one of the CV joints during the throwout bearing replacement, I ended up replacing both CV axle assemblies. The new passenger side CV axle assembly came with a new carrier bearing. Once I replaced the CV axles, the whine went away. Therefore, I'm pretty sure that the whine that I was hearing after the throwout bearing replacement was caused by the dealer improperly mounting the carrier bearing.

A possible reason that so many manual transmission Fiesta owners have the whine is that aligning the carrier bearing is a little tricky. The outer side of the outer race is rounded. This keeps the axle from moving in the lateral direction. However, the carrier bearing does not self-align very well during the mounting process. To attach the bearing to the mount, you need to carefully seat the bearing and wiggle it back and forth until you feel that it is properly centered. Once it is centered, you then need to attach a new bearing strap (and carrier bearing shield, if you car has one) and put both nuts on the threaded studs that hold the strap (and shield) on without moving the bearing. Again, you need to keep the bearing in firm contact with the bearing mount during the assembly process. You then need to tighten the nuts about an 1/8 of a turn at a time, going from one nut to the other a few times, before using a torque wrench to get the proper torque. Since the bearing strap will permanently deform during the tightening process, it cannot be reused. If the bearing is not perfectly centered when the strap is tightened, the bearing will be cocked a little, which will cause the balls to ride on the edge of the races, instead of the center.

Thank you for taking the time to make this post! I just replaced the throw out bearing and was trying to diagnose a noise, thanks to this post I was able to realign the carrier bearing and eliminate the noise, you probably saved me a trip to the mechanic, thank you.

 

[Thwarten]

Any explanation for this? I recently had a trans leak at the back-up light switch. Lost a decent amount of trans fluid. During this I started to get the whine in 5th gear, exactly as described earlier in the thread. I've since stopped the leak and topped off the fluid but whine still persists. Trying to get a definitive explanation to determine next steps.

Had the exact same issue, noticed transmission whine, inspected transmission and found the reverse light switch connector had broken off and dumped fluid all down the front of the transmission. Topped up fluid after replacing the switch, road tested, whine is still present around 120 KM/H+, improved from around 100 KM/H+. Hoping that reviving this thread, someone will maybe have found some answers.