No blown-up transmission thread, but posting this to help others if they have similar modifications as I do.
2016 Fiesta ST, the first owner
83,593 miles
failure: 5th gear sent to the moon; I have yet to pull the transmission, though. The car will stall in neutral while letting out the clutch; I can hear clunking (perhaps the shaft snapped, doesn't want to roll in neutral either).
Mods: Spec lightweight flywheel, Spec unsprung stage 5 clutch (sintered Iron), M-sport R2 axles, Wavetrac LSD, New Transmission bearings, G25-550 (~was around 400hp), 4-port Aux Fuel, 225/45/r17 Federal RSRR's and a ton of other irrelevant modifications.
The car has an ign cut FFS setup (cobb fuel cut FFS wasn't able to slow the rpms down enough), blew up while flat foot shifting from 4th to 5th on the highway near 100 mph. I started with a pull from 2nd gear, and I flat foot shifted every gear change from there to where it blew up (5th gear). The Transmission was torn down, and all bearings were replaced about 20k miles ago at ~60,000k miles. Didn't replace any gears, as they all looked fine, and it has survived 20k hard miles since the rebuild (probably had some cracks I couldn't see). The big turbo setup was installed around 5k miles ago, at 77k miles. Unsprung clutch and LWFW have been on the car for 40k miles, and I replaced the disc and friction surface simultaneously as the transmission was overhauled.
Not sure what direction to take the car next. I think if I buy another factory transmission, it will likely suffer the same fate. There don't seem to be any companies that offer aftermarket gear sets, and the companies that offer rebuilds probably aren't that much stronger of a transmission. Looking into swapping to the Fiesta R2 transmission because it is much easier to rebuild (splined gears instead of press-fit) and utilizes straight-cut gears, which are easier to design stronger. The data I've found on it claims that it's rated for up to 1000nm to torque, which is far more than I need for this car. Did anyone swap the Sadev R2 transmission into their Fiesta ST yet? At ~$5,500 for a brand new box, it seems pretty reasonable. I was able to find some used spares around the $2.5k-3k range, will need the tarmac gear ratios because the gravel ones seem way too short for the street.
Any info is appreciated!
2016 Fiesta ST, the first owner
83,593 miles
failure: 5th gear sent to the moon; I have yet to pull the transmission, though. The car will stall in neutral while letting out the clutch; I can hear clunking (perhaps the shaft snapped, doesn't want to roll in neutral either).
Mods: Spec lightweight flywheel, Spec unsprung stage 5 clutch (sintered Iron), M-sport R2 axles, Wavetrac LSD, New Transmission bearings, G25-550 (~was around 400hp), 4-port Aux Fuel, 225/45/r17 Federal RSRR's and a ton of other irrelevant modifications.
The car has an ign cut FFS setup (cobb fuel cut FFS wasn't able to slow the rpms down enough), blew up while flat foot shifting from 4th to 5th on the highway near 100 mph. I started with a pull from 2nd gear, and I flat foot shifted every gear change from there to where it blew up (5th gear). The Transmission was torn down, and all bearings were replaced about 20k miles ago at ~60,000k miles. Didn't replace any gears, as they all looked fine, and it has survived 20k hard miles since the rebuild (probably had some cracks I couldn't see). The big turbo setup was installed around 5k miles ago, at 77k miles. Unsprung clutch and LWFW have been on the car for 40k miles, and I replaced the disc and friction surface simultaneously as the transmission was overhauled.
Not sure what direction to take the car next. I think if I buy another factory transmission, it will likely suffer the same fate. There don't seem to be any companies that offer aftermarket gear sets, and the companies that offer rebuilds probably aren't that much stronger of a transmission. Looking into swapping to the Fiesta R2 transmission because it is much easier to rebuild (splined gears instead of press-fit) and utilizes straight-cut gears, which are easier to design stronger. The data I've found on it claims that it's rated for up to 1000nm to torque, which is far more than I need for this car. Did anyone swap the Sadev R2 transmission into their Fiesta ST yet? At ~$5,500 for a brand new box, it seems pretty reasonable. I was able to find some used spares around the $2.5k-3k range, will need the tarmac gear ratios because the gravel ones seem way too short for the street.
Any info is appreciated!
![[dunno]](/images/smilies/icon_smile_dunno.gif "Dunno [dunno]"){kind=icon}
![[wink]](/images/smilies/wink.gif "Wink [wink]")
