MR SST Transmission Kaput

What happens to an EVO X MR TC-SST (twin clutch) transmission after 16,000 race miles? The same thing that would happen after 16,000 race miles with a manual 5 speed from a GSR or any other rice, bread, or kraut burner. The trans would be broken or at the very least on its way out. If the gears didn’t break, the synchros would be toast.  While the failed SST trans may sound like a premature failure, the reality is that most any production car transmissions are not designed to last that long under racing conditions. This is why race teams “mileage” transmissions. Even in stock class racing like Super Taikyu, Grand Am ST, SCCA, or NASA racing, teams generally do not use transmissions for 16,000 miles. I think I remember Sean saying that Super Taikyu BNR34 GT-Rs would change Getrag trannys every race weekend or 2000km (whichever came first). Even open wheel cars have their gear stacks taken apart and inspected after a 50 minute sprint race.

The black EVO X had lived a very hard life up to 18,000 miles which is right about the time I took possesion of the car. I believe it started life as a development mule, then it went on to live as a media mule for the big mags like C&D, R&T, etc. (the car is fully loaded), and then a Gumball China race car where it raced across China pretty much flat out. So maybe I shouldn’t call them “race” miles, but they were definitely hard as hell and definitely way harder than the average daily driver is driven. The MR’s transmission fluid temperature is generally a problem and therefore must be changed regularly. Mitsu recommends changing the fluid once a year I think, but if you change tranny fluid with every engine oil change, you’ll feel the transmission’s crispness come back immediately. I’m sure when the car was in MMNA’s possession it was well maintained, but I doubt during the 10,000 miles it spent blasting around China it was not.  In rural China where the tap water is still brown, I am pretty sure there is no Mitsubishi Diaqueen SSTF-I available.


Usually I leave the car at Pete’s place and he usually drives it, but one of the few days I drove the car it gave up earlier this year at around 22,000 miles. I was getting on the 22 freeway west full blast in the black EVO X and slapping paddles. Going from 2nd to 3rg gear it seemed to pop out of gear except the only problem was that there is no shifter to be popping out of gear. I pulled over on the side of the freeway and it would just make grinding noises when I revved the engine. Shifting it in to any gear resulted in no forward motion. I was sure it was kaput at that point so thank god for the AAA Plus membership. The car is nearly stock so it’s not like it made a shit ton of power or anything. I believe it was just beat on for a damn long time without the proper maintenance. The fluid did come out really thin and near black just like it did 4,000 miles before. I guess I should have asked Pete to flush the cooler and the trans. So I put a call in to a buddy at MMNA and by some miracle they had one in stock. What a cool guy:

The trans is probably a bit easier to change than the 5 speed since there is no clutch. The transmission’s sheer size is what makes it difficult to remove and replace with the damn frame rail so close. I can tell you though that the car has never felt so good with the new SST trans. The MR with a healthy SST transmission is definitely awesome to drive. I think Mitsubishi’s product development team really hit the spot for a street car as long as you don’t ask it to shift at 400whp. For a daily driver I recommend the MR over a GSR any day of the week. Everytime I drive a GSR (and I have been driving one daily for the past 6 weeks), I’m reaching for 6th gear because you’re at 4000rpm at 80mph. When I drive a GSR I sometimes think to myself, “WTF is this a Civic with a B16?” Stick to the MR if you’re my age or older and don’t want to deal with a buzzy car. You’ll thank me later. Otherwise the MR has been perfect with minimal squeaks and rattles even on the HKS Hipermax III coilovers (it is a rice burner afterall). The car is back with Pete and he’s driving it while ARK Design conducts their exhaust testing on his 370Z.

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