Add me to the list of broken MR trans owners.

I was at an open track day with my Evo MR (2005) today and had a catastrophic trans failure. At Pocono today, heading down a straight in 4th, the car started violently shuddering. I pulled off immediately into the infield, and coasted to a stop.

Car will go into gear, but hit the gas and an awful grinding sound comes from under the car and it will not move. As I pulled off the track into the infield, the driver rear wheel seemed to lock up. Now, the wheels will move (barely) with a lot of pushing on the car.

Car is a 2005 with ~21k on the odo, including many track days and 60+ days of autocross on it (most with 2 drivers). Running about ~300 whp. (stock w/ a tune on TurboTrix Dyno)

Has an Exedy Stg 1 clutch put in at 17k by Turbo Trix; they told me they replaced the stock fluid in the trans w/ Mitsu OEM MR fluid that I brought them.

The 2hr flatbed home was great fun! Yippie. Fortunately, a good friend took great care of me by picking up the car and we had a chance to BS.

Random pics of the car. Why? Dunno.

 

condolences . I really wonder if these failures are happening in the JDM and European cars too, it seems odd that none of the usual shops are offering 6MT cooling kits, especially since they've had it longer than us.

 

From what I can tell I haven't heard of and IX 6 speeds failing. I wonder who's will be the first to go... (knock on wood). I was gonna get exhaust on my car for Chrsitmas but this just jumped to the top of the list. I really can't afford for my tranny to sh*t the bed.

 

That was part of the discussion a while back. I think there have been one or two IX failures, and the parts numbers were supposedly cross referenced to the VIII's, and (IIRC) they were the same... Only one gear was referenced to either the input shaft or output shaft, and I think it was assumed that the other part was also the same. Either way, if one is the same part number, then it's at least the exact same size and fitment.

I would also really like to hear from overseas, such as Europe and Japan. I wonder if they are having the same issues and/or what's being done to combat it.

I wouldn't mind having the 5sp, but I REALLY don't want to pay for the conversion. If someone was willing to do a 5sp swap I'd me more inclined. I could do the install myself but again, its a huge PITA if an oil cooler and better fluid is sufficient protection for 20min sessions.

 

Matt2.8NJ: Sorry to hear about your tranny ... Did you only have a tune and clutch installed on the car (no other mods)? Any chance you remember how many track days you have done?

 

Just a tune and an Exedy Stg 1 clutch.

Maybe...7 track days on this car. However, until yesterday I took 2 years off from the track... of course, my return to HPDE's yesterday was a disaster....

The trans fluid was only a few months old, zero track days on it, just a few autocrosses.

I wonder if there was an issue that the clutch install caused on the tranny...

 

For a given size gear, generally a helical gear will be able to transmit more torque than its spur gear counterpart. Of course this is dependent on the contact ratio of both sets and the helix on the helical, but almost always a helical gear will share the load better amongst the gear teeth (more teeth sharing load = lower stress per tooth. As said before you also get a much quieter operation with a helical. The drawbacks of the helical are its cost to manufacture and the efficiency of the mesh. The thrust component introduced into a helical system lowers the overall mesh efficiency as compared to a spur gear.

I don't know if anyone has too much info on 4th gear but I would be interested in knowing several things. If anyone knows, I would appreciate the tooth profile, the spline spec for the internal spline, the material, the hardness, and depth of hardness. I know there was talk about examining a gear earlier, I just don't know what ever happened with that. If you have some info, thanks in advance.

 

The 4 gear was never purchased due to price as you can't purchase it seperatly..so it was never tested unfortunately.

 

Here is a tranny oil analysis from Blackstone Labs using a MOPAR 75W-85 full synthetic exact equivalent to the Super DiaQueen. THought it would be interesting to share. BTW, this was my baseline.

BTW, I have never tracked or dragged my car...yet.

 

Interesting comments. So it sounds like the transmission is a great design by itself. (was this for the 5sp or 6sp? If 5sp, it's only partially relevant since the two are entirely different). Have you done any mods to the car?

The consensus seems to be that the transmission is plenty strong, just heat buildup is causing a breakdown in the oil first, then the metal hardness softens. As a result the metal teeth fatigue and shear. Daily driving seems to have absolutely no abnormal effect.

 

I drive an MR, now with 70,500 miles on it. Mods are in sig

BTW, no 2nd gear grind with this MOPAR fluid. I've been using this fluid since 12,000 miles. Then again, at $20 a quart, I would expect it to be "better."

This shows me 2 things. 1, this fluid is at least as good as the Super DiaQueen, if not better. 2. I also agree that this particular data point suggests that the MR problems show up with heat/abuse. But then again, it's just one data point.

Thought I would share with the group

 

Hey guys,

Ive got a 9. Ive been to the track at least 10 times this season with my car with no tranny issues running it at its fullest potential. A couple of these were with AMS during thier track days and I was an instructor. On those trackdays, the car only had time to rest while the passanger/student/AMS employees changed in the pass seat. Almost ran every session, back to back, on those days.

Car now has 27k on it and was first at the track with only 600mi on the odometer when I got it last year. Ive been to Road America in it several times, Autobahn tons of times and have been known to screw around/drift in the wet. I also Ice solo on lake Hustisford with it. I also admit to launching it with the launch control many times.

At 27k, the stock clutch is starting to slip. No other technical problems with the car.

TBE, Drop-in, AMS flash. 28psi on race gas on the track. 312whp on pump.

1 qt Super light weight shock proof topped off with MT90. Same as we run in our road race Prelude.

Heavier oil will INCREASE temps. Shearing thicker oil produces more heat. Not shifting correctly and using your engine and trans to help slow you down creates the most heat. I'd have to say first its technique, second its the oil.

I wouldnt trade the 6spd for the 5 if you paid me. 6spds is always better for accel on a road race track. Closer ratio. And remember, theres peeps out there that have figured out how to break shep trannies. Dont give up.

MHO.

 

I miss the days of engine breaking

I don't know about you guys, but I have some significant throttle hang when I downshift - I'm subscribed to another thread where they are discussing how to programmatically reduce this, but the question has surfaced as to whether or not that was developed to reduce the wear and tear on the drivetrain.

Thoughts?

 

The only time my MR did that was when I unhooked the factory launch control switch on the clutch.

 

Lawrence, those are very inspiring words... Hopefully there's some truth to it because I tend to agree. What do you mean by using the engine and tranny to slow the car, you mean not rev-matching for downshifts?