Greetings folks. I recently completed the rebuild of the transmission in my FiST after it developed a whining noise. I had noticed the noise, along with a sort of rattle, growing stronger over the months leading up to it getting really bad. The noise was there but it was quiet. I took the car to PittRace with the local Porsche Club / Audi Club for an HPDE back in May. On day three of the event, the noise had grown so loud that I skipped the last couple sessions in favor of hoping to get home. (I live in the DC area) Thankfully I made it home and decided that I would give it a go myself. I have the means; a garage, second vehicle, so I figured what could be the worst that could happen? (failure, need to replace the trans again) - So let's give it a shot. I started doing the research, making lists, etc. Had some friends assist with the removal. (followed along with the OEM shop manual) Breaking apart the trans didn't reveal any "ah-ha!" issues. (bummer) so I gave it my best shot by replacing the bearings I most thought to be suspect. Put the trans back in and, voila - the issue was still there. ( /facepalm ) I decided to pull it back out (didn't have to remove the subframe!) and replace the rest of the bearings, including those on the input/output shaft themselves (those needle bearings on the shaft. had to replace a few gears.)
Well, this time it worked. Was quite a journey. After a couple weeks I took the car to VIR last weekend for a season-ending HPDE with the Audi club. It was fantastic. The car drives and performs nearly the same as it did before, when things were normal. As someone who's never done any transmission work, it was quite pleasing. Anyway, for anyone who's interested, I did a writeup on my blog, here:
http://blog.sluggyjunx.com/rebuilding-the-transmission-in-my-2014-ford-fiesta-st/
If you have any questions, comments, ideas, etc. please toss them my way. I don't get on these forums as much as I'd like (no access during the day) but I'm around. Feel free to message me. Good luck!