Blown up transmission, Rebuild options?

[settlingabyss12]

Guess I jinxed myself posting in this thread. But just had a similar failure in my transmission at 85,500 miles. During a downshift to 5th from 6th getting ready for a pass on the highway while just cruising at 65mph, heard all kinds of noises and 5th gear was like neutral. 5th and 6th are now neutral while 1-4 work but make terrible noises. Luckily I have a spare but it is not ready to go yet so not sure when I will get the car going again.

Sad to hear, let us know what failed on the trans, curious to see if it was the gears or the shaft.

Id be surprised if it isn't the input shaft, they tend to snap.

I think my input shaft is what snapped. I can start up the car and it idles perfectly fine, but if I let out the clutch, you can hear clunking from the transmission (even in neutral), and If the clutch grabs enough, it'll make some terrible noises and then stall.

I have not had the time to tear the car apart to see what the damage looks like, been very busy with work. It's probably going to have to sit in my shop for a little while.

 

[settlingabyss12]

The third time we changed the transmission, it was making a whining / broken exhaust sound. It could be the transmission, not the exhaust lol

Probably worth it for anyone running an aggressive unsprung clutch/LWFW setup or sticky tires to have a spare transmission as a "just in case" especially if it's your daily driver. They don't seem to be that common to come by locally.

 

[MagnetiseST]

I think my input shaft is what snapped. I can start up the car and it idles perfectly fine, but if I let out the clutch, you can hear clunking from the transmission (even in neutral), and If the clutch grabs enough, it'll make some terrible noises and then stall.

I have not had the time to tear the car apart to see what the damage looks like, been very busy with work. It's probably going to have to sit in my shop for a little while.

Sounds like the input shaft to me!

 

[jehiel]

well i have a fiesta st 2016 , 85 000 km on the clock & my gearbox burnt off . the gearbox specialist said it was due to no transmission fluid in the gearbox .
i was on the highway when this happen , it kept slipping from 6 & then eventually was not taking any gears .
what could possible be the issue ??

 

[haste]

well i have a fiesta st 2016 , 85 000 km on the clock & my gearbox burnt off . the gearbox specialist said it was due to no transmission fluid in the gearbox .
i was on the highway when this happen , it kept slipping from 6 & then eventually was not taking any gears .
what could possible be the issue ??

Lack of fluid is usually caused by a leak. Low fluid level or no fluid will definitely burn up a tranny. Some ST transmissions were also known to be underfilled from the factory.

Did you ever have the transmission serviced(fluid changed)? 85,000 km is past the maintenance interval for transmission service.

 

[jehiel]

Lack of fluid is usually caused by a leak. Low fluid level or no fluid will definitely burn up a tranny. Some ST transmissions were also known to be underfilled from the factory.

Did you ever have the transmission serviced(fluid changed)? 85,000 km is past the maintenance interval for transmission service.

When I bought the car it was on 83 000 km
According to the service book the service was done. Not sure if they drained the transmission fluid and then forget to re-fill it back . I've only had the car for 2 weeks and this happened. I did source another 2nd hand gearbox , hopefully it does fit on the st though ...

 

[Magnetic]

I guess my dad was right. SO glad I never flat foot shift. Bummer but inevitable when driving like a Hoonigan I guess.

Need a real racing transmission for it to last probably. It will probably have to be built fairly often too.

 

[Sam4]

Sounds like the input shaft to me!

Ya know, I hit "like" above, but I don't like! How many car's have we driven into the 120's before the clutch was kaput, forget having a broken shaft. (Full disclosure - I had to replace the tranny in my 1980 Mk I, but 100k+)

 

[Magnetic]

Ya know, I hit "like" above, but I don't like! How many car's have we driven into the 120's before the clutch was kaput, forget having a broken shaft. (Full disclosure - I had to replace the tranny in my 1980 Mk I, but 100k+)

They certainly don't make em like they used to sounds about right to me, especially in your case. IT's all about light weight inexpensive manufacturing bottom lines.

 

[Hydancell]

Hey, just stumbled upon your post and thought I'd chime in. I've got a 2015 WRX and went through something similar. Had a lightweight flywheel and upgraded clutch, and after some spirited driving, I ended up shredding 4th gear. It was super frustrating because, like you, I had just rebuilt the transmission not too long before.

I debated whether to get another factory transmission or look for something stronger. I ended up finding a great deal on 700r4 transmission for sale for my buddy's Camaro, which got me thinking about alternatives. I eventually found a beefed-up gearbox that could handle the extra power, and it made all the difference.

 

[kuvduvod]

From what you've described, it seems like you're leaning towards the Fiesta R2 transmission as a potential upgrade due to its durability and straight-cut gears.
Personally, I think exploring the R2 transmission could be a solid move, especially with its capability to handle higher torque levels compared to the factory setup. Swapping to something that's easier to rebuild and known for stronger design could offer more peace of mind in the long run. If you're still weighing options, I recently came across a 700r4 transmission for sale that might provide another perspective.

 

[M-Sport fan]

^^^I am guessing you were directing this towards Magnetic above?

If so, just be sure to stay out of any and ALL stop and go traffic jams, and be ready willing, and able to (either paying someone big buck$ to do so, or DIY) rebuild that Sadev sequential every 3K-5K miles or so.

Those gearboxes were really never meant for daily street use, at all.