Shooter McGavin

Hey man, I have been having the exact same issue since 2017, mitsu did nothing but quote me 21k for a new tranny. Any chance they told you what was wrong with yours? I would love to fix the car but not at 21k

DaEvoPusha

Hi guys, I'm having an issue only on track days (HPDE) that I'm hoping you can give me some advice on. I went from completely stock to a tune, 3-port, high-flow cat, and the Dodson Sump this past late-winter. I was occasionally getting transmission overheat on track days. I now have one autocross 'practice' day and 4 track days in the last 5-6 weeks, always in super-sport manual, no more overheats, but a different issue.
I've learned what I do in the first couple sessions doesnt matter much- how long I stay on track consecutively without getting off to cool down, if/how long I spend cooling down (as a precaution) before getting back on track, how high of rpm's I run/which gears I'm in on different parts of the track, etc. Generally on a midday session, I'll get off or get back on track and the TC-SST starts acting funny. It seems prolonged overall TC-SST stress(?) brings on the issue.
1) For example I could be in 5th gear at 1/4-throttle maintaining speed and the engine starts revving- like it "lost" the 5th gear it was in, disengaged. When I let off the throttle and the rpm's start falling, it will re-engage the gear, but might be a bit of a judder. Or, it wont re-engage the gear (example I'm in 5th) and the rpm's fall to what the crankshaft's speed currently is (say around 2K) and the revs start bouncing around for a second or two, then finally re-engages 5th gear. If I try to shift gears during this process, I may or may not get a "Transmission Service Required" warning and the "Service Engine Soon" light comes on.
2) Another example, I get off track in the middle of a midday session to cool down for a couple of minutes. Shortly after getting back on track, I'll try to shift down or up somewhere and the TC-SST wont shift. I then get the "Transmission Service Required" warning and the "Service Engine Soon" light. Some times I lose all odd-gears, some times I lose all even-gears, and some times I cant shift at all- it's like the TC-SST goes in to some self-preservation limp mode. Let's say I'm stuck in 5th gear (come to think of it, maybe it's often 5th gear that gets jacked up?!)- I have to get off track, turn the engine off and on, thus putting the car on a fresh start in normal+automatic mode. I can drive OK at that point, albeit maybe with some oddities during the car automatically shifting. If I then turn the engine off and on, at some point later in the day upon a new ignition start the warning lights all go away on their own and the car works perfectly normal. I never have issues with normal street driving, 67K miles and meticulously well maintained.
I'm going to check with the local perf. shop for their opinion and to ask how much trans. fluid they put in (I provided OEM diaqueen). I'm probably also at some point going to double-check the fluid level and filter myself. Sorry for such a long post, but do you guys have any advice for me at all? I cant be the only person that's had this type of issue only on track days.
If there are no current warning lights at all in the car, I cant go to an auto shop to pull a code, correct?

DaEvoPusha

The dealer pulled the TCU codes with the MUT3 today. My stored codes were P184B- shift fork 4 and P2733- clutch shift c/o sol 1 stuck. It looks like shifting in or out of 4th is causing the issue, but I think it's the 4th - 6th gear shift fork because often shifting from 5th to either 4th or 6th is what pops the transmission service required. I'm fairly certain I had one shifting 3rd to 4th, when I had been as high as 6th gear some seconds prior- so at that point I guess the shift fork was stuck on 6th, not moving back to 4th.
I'm optimistic taking the ~8.2 liters that were in the transmission out, and putting back in the appropriate 7.2 - 7.3 liters. I'll find out at BIR this weekend.

Capt_Insano

Pusha,

This probably isn't any help, but the "losing/disengaging" gear issue sounds similar to what I had when mine was overheating before losing the whole gear box. It seemed to struggle to hold a gear. I was in auto instead of manual, but I could see on the display that it was jumping from gear to gear, seemingly trying to find one that would stick, and eventually none of them would. If into/out of 5th is the issue, then possibly a shift fork? Although when mine went it was all the odd gears, not only 1 or 2 like you might have. From what I have read about this transmission, you're doing what I would think is the best 1st step by checking the fluid level since I hear too much can cause overheating just as much as too little can. Hopefully that's the issue instead of the forks

Capt_Insano

My SST failure (good ending?) story:

Model: 2014 MR, no mods
Mileage: First Signs, ~58k Problem sticks, 68k
Issue: Lost 2nd, 4th & 6th gears because of gear fork failure. Unresolved overheating after transmission replacement.

Issue was initially random and would disappear after ~1 mile. Because it was intermediate, and I couldn't even get the codes to stick around by the time I got to dealership, never went because I knew they wouldn't do anything. But it happened to me real close to 60k and the shop was actually open when it happened this time, so I took it there without shutting the car off (so the check engine light would still be on when I got there even though problem was gone). Pulled in with 59997 on the ODO, but again, since the problem was present Mitsu wouldn't do anything but note it happened saying hopefully if it stuck soon, the history would possibly convince Mitsu to cover it (lol).

Fast forward 6 months & 8k miles and problem appears & sticks during some "spirited driving". Take it back to dealership, they confirm the issue and say only solution is a replacement, but obviously they will no longer cover it, which ended up not being too terrible since the Chevy dealership I got the car at sold me a ~$3k warranty that covered this $14k+ repair (not including a month of a rental). Biggest problem was that this all took a month to get fixed as a result of it. While it's at the shop, battery goes totally flat so need a new one of those. Once everything was put back together, the starter was also found to be bad I guess? So warranty gets me one of those too.

Pick the car up right as the shop is closing on the hottest day of this NE summer, super happy to be back in my baby. Trans overheats 30 minutes later on the way home, not pushing it anymore than I usually do, leaves me stranded on the side of the road because it can't find any gears. Tow it back to dealership. 2 days when they open back up they say they took it out for 2 "extended test drives" and since nothing happened, they are attributing it to the high 90 degree weather and can't do anything. I reluctantly say fine. But a few weeks later, I'm rolling down the highway, going probably ~90mph for half hour but in 6th so RPM's not high, then I get overheating warning again. Back her down to 60-70 and was fine after that, but shouldn't be overheating like this, so my next move is to check fluid levels to make sure dealership didn't screw that up. Any other thoughts? No autocross' or HPDE since the replacement.

DaEvoPusha

Coincidentally, I just got my TC-SST repaired yesterday. The shift fork 4 was replaced with the Dodson one, and the entire valve body was replaced, then the trans was re-programmed- necessary when replacing the valve body. Shift fork 4 I believe is actually gears 2-4, I erroneously said 4-6 gears earlier. The only explanation I can give for the oddities with losing gears and whatnot is a failing valve body. It's so hard to be sure without spending more $$$ to send it to Kozmic and have them do tests on it. A home garage guy like me can only speculate.
I think with the 2 to 4 shift, the TC-SST thinking the shift didnt happen correctly wigs out the trans, contributing to "losing" 5th. The shift fork magnet replacement should alleviate this forever, as the original magnet, you can read online, gets loose and mis-aligns with the sensor. I'll post pictures and more info later.

DaEvoPusha

TC-SST Shift fork 4 magnet

TC-SST Valve body

DaEvoPusha

Was your new TC-SST installed then by the Chevy dealership/their appointed shop, or by the Mitsu dealership?
Definitely check fluid. Per the service manual Mitsubishi says to put 5.5 - 5.8L (I dont have time to look this up) in a stock TC-SST. I've never seen an EVO X owner, or even heard of a dealership, put that low of a quantity in. I dont recall the quantity my TC-SST had in when I first changed it. Most people agree about 7L is appropriate. Jack's transmissions says 7.5L+. I've been using 7L for about 6 years, including about 10 track days and some autocross, and I've not had an issue until the valve body issue. I dont think the fluid level was a factor, but it's impossible to say. A lot of people have had the valve body go bad, so I doubt it's that all of us are putting the wrong amount of fluid in.
I would also check that the OEM transmission cooler is connected properly- the lines going in and out. You might as well also make sure the external filter is connected correctly when you check the fluid level, and that there arent any leaks anywhere- particularly where the transmission mates to the engine and the ACD.

Capt_Insano

All repairs were done by Mitsu. Definitely didn't trust Chevy to do it. Been too busy to check it yet and need to get smarter on how to actually check the level, but I'll definitely check out all those connections too. Think it's necessary to drain everything out? Or just top it off if it's low?

DaEvoPusha

Tragically, the OEM TC-SST doesnt have a dipstick. There are aftermarket products with an oil reservoir that incorparates a dipstick, but not on the stock unit, and not on my aftermarket Dodson sump. The only way to check the fluid level is to drain all of the fluid out, then measure the fluid level in something like painters cans or what-have-you to see the total quantity. It's really not too bad to do. The most annoying part is getting all of the plastic tabs off of the underbody tray to remove it.
After you know the fluid level, you can then determine if you need to put less back in than what you took out, or put it all back in plus some more to get to the right level.

Capt_Insano

Thought I read something where you could pull some bolt somewhere and then you had to wait until the fluid only tricked out of the hole or something. But if the solution is to just drain it then fine, that's not too terrible. It's a bummer they couldn't have include a dipstick. I have heard about those aftermarket coolers and they sound super convenient. but can't justify one of those over other stuff.

CFMP RAblue

There is a full level check bolt on the drivers side but you need to modify an Allen socket (cut the length down) as it is a tight area to get into. Most however do just drain and refill as the quantities have been measured a number of times and are known.

Teddy 2011MR

2011 Evo MR 166,000 miles when transmission service light came on. I hadn't had any issues for 2yrs of owning the car when I went around a turn and the car wanted to stop and go, very jumpy. I pulled right over and that's when the light came on. My codes were P2733, P0777, P1836, P181E, P184B, and P0420. I am lucky I live in Colorado Springs so I took it to Jack's transmissions where they found the transmission oil pump went out. They replaced it with a new one and the car is functioning well again.

richardjh

Well, I'll have to put my hand up and be counted here:


My SST has had five fluid changes in the car's 165,000km lifetime.

The first two fluid changes involved 7.1 litres of replacement fluid, plus 0.3 litres if the SST filter was being changed.

For the next three changes, I used 5.5 litres, again with an extra 0.3 litres if a new filter was going on.


This is a Ralliart with an unmodified SST. Original Mitsubishi Dia-Queen SST fluid used. No Evo X TCU program reflash (no S-Sport). The car saw a lot of autocross and long track driving, although I kept the laps short and the cooldowns long. It also worked hard through some 600 ECU reflashes for patch/basemap R&D, including a great deal of work on ECU-side "SST requested torque calculation" management.

Rich

PS. There was no noticeable change in SST behaviour when the Dia-Queen fluid quantity was reduced by 1.6 litres. This transmission never gave me a SLOW DOWN message on track before or after, and hasn't thrown a code or gone into any kind of limp-home mode. One of the good units!!

DaEvoPusha

I'd be interested to hear how common it is for people to track their X MR with 5.5 liters, and what results they had in terms of cool down messages. I can generally get through 20-25 min sessions early in the day, but as I get to later day sessions I get overheats. Obviously the ambient temperature and how hard I'm pushing the car make a difference. I'm generally now taking brakes every 10-15 mins. It would be nice to be on track for all of my time, but the TC-SST just doesnt seem capable of that, no matter how much aftermarket cooling you try for. I might try the AMS replacement cooler this winter, in preparation for the spring.
I've never tried anything other than ~7L, except when I put the Dodson Sump on early this year I'm now running about 7.4L. I always change the filter at the same time I change the fluid.