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Never Ending Clutch Disengagement Problems

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RusherRacing

15+ Year Contributor
142
1
Jun 21, 2006
Yankton, South_Dakota
DSM tranny problems...

90 Eclipse GSX

I will start from the beginning...

I purchased the car last July. The car is set up for road racing.

Current Drivetrain Mods
New ACT 2600 street disk
ACT chromoly Flywheel
TRE stage 2+ Galant VR4-RS Trans
New Seals in Transfercase
New axles, bearings, tie rod ends, sway bar end links, basically any drive train part, and if replaceable were replaced before I purchased the car.

All the work was done by my master mechanic Brad, he was a mitsu tech for a few years and has worked on multiply extremely modded DSM's unless otherwised stated.

Now here is the story, from memory unfortunately
First event AutoX July 06'
Transmission came loose after the 3rd run!
Created small crack in bell housing
Had Joey at Excessive Autosports in Sioux Falls pull the transmission and weld the bell housing and reinstalled.
Second Event AutoX Aug 06'
Ran fine
Third Event Drag Racing Sept 06'
Ran ok was having some clutch disengagement issues but just thought I over heated the fluid..
Winter-Didn't do much with the car, purchased and remodeled a new house...

07 PreSeason
Changed all the fluids, checked all fasteners making sure everything is tight...

1st event of 07 Drag Racing TnT

Clutch worked good at first (disengagement point seemed low) Slowly got worse throughout the day. Loaded it up since didn't want any thing else to break.

Ordered stainless steel braided clutch line and extended slave cylinder rod, bleed Clutch again and the car already had the extended slave cylinder rod...

2nd event went to MAM for a driver's school, and the car made it through 3 sessions before clutch stopped disengaging.

Put new clutch line in when we got back, and installed a new master cylinder (I just had to try something) prepped for AutoX...

3rd event AutoX continuously bleed clutch found a major problem a quarter size whole in the bell housing..
Pulled the transmission sent it off to Jon at TRE(thanks for the great work Jon) for a rebuild and weld the case since I had to pull it out. I also ordered a new Clutch, Pressure Plate, throwout bearing, and flywheel all from ACT(maperformance). Brad noticed a couple things the spacer between the block and trans was missing, one bolt and spacer on the driver side axle was missing, and the reason for the whole in the trans was we sheared a pressure plate bolt. Brad also happeneds to work now at Chrysler parts department.. So we ordered all new OEM fasteners, spacers, seals for transfercase...

Put it all back together everything worked great. Loaded the car up and headed to MAM for the NASA event. Ran 2 sessions with no time to look over the car in between (I was attending HPDE 2 so I had classes) as I was finishing up the second session the car seemed to shift a little more difficult, I just took the time to look over the car... Red oil every where... Redline heavyweight... Input Seal on the transfercase went to crap. Had a friend bring me my spare case, put that back in ran again the next morning I ended up being stuck in 4th cause the damn trans wouldn't disengage finished of the session working on my line etc. I brought the car back in and oil again everywhere and again redline heavyweight.. The same damn seal went bad. Loaded up headed home, knowing my problems weren't solved...


Pulled the trans back out thinking the disk may have been swelling with oil. The disk measured .305" (act new is .315") so the disk wasn't swelled. I then also had my dad who has been a diesel mechanic all his life look at it. The only thing he could think of is the throwout bearing had a little slop, we compared it to my spare transmission and the sloped seemed consistent and they both measured about the same (don't keep measurements).

I decided just to spray down the disk in brake fluid and reistalled it. It didn't work  It kind of sounds like its over traveling (however it still never disengages). So now I am pulling it back out because with that sound something should show wear or some scratches.

Any thoughts? I spoke with Mike Reichen (215.9 mph standing mile..) with his EVOII and he suggested installing a 96 GST slave has longer stroke and a unsprung 6 puck he said its thinner? Does anyone have any other thoughts...
 
Last edited by a moderator:
Update,

I am going to go head and pull the pedal assembly out tomorrow, drop the trans back out, double check everything, put a new slave cylinder in, weld the pedal assembly if it hasn't been done already, it doesn't look like it and the pedal doesn't have any slop to speak of but I am going to go through everything just cause. I need a car I can race not work on!
 
Have you replaced the clutch fork yet? The cat who did my clutch mentioned that the forks wear, sometimes bend, especially with upgraded (2600+) pressure plates. Some guys will shim the ball, as a cheapie fix, (we did that to mine, just to be "safe"OMG) but it sounds to me like your fork is going south. I didn't look at my fork too closely when it was out, but maybe it could be reinforced somehow.

You could PM this guy http://www.dsmtuners.com/forums/showthread.php?t=256298&highlight=clutch+engagement & find out if he found an answer.

I love my sprung puck-style disk FWIW, but that shouldn't affect the problem you are having. The friction surface needs to be close to the same thickness to function at all.
 
In your previous post those problems are hard solutions. Mine get worse with time? It worked great when I first put the TRE trans in. Also it has a new pivot ball. The fork looked fine, I examined it carefully however I didn't replace it. I will call my friend/mechanic/parts guy and have him bring one down when he comes down to party this weekend. What bothers me is the the time variable in this problem, geometry won't change with time unless something is bending or becoming loose which we can't find to be true? But I will post up the results when its FIXED!
 
Have you replaced the clutch fork yet? especially with upgraded (2600+) pressure plates. but it sounds to me like your fork is going south.

Mine get worse with time? I examined it carefully however I didn't replace it. geometry won't change with time unless something is bending

This ^^^^^ is what makes me think it is the fork bending, since all other common fixes have been exhausted.
 
Get rid of the extended slave rod. It's doing nothing to help and can only hinder your setup when your disk/flywheel wears over time.
 
Your problem sounds very similar to what I went through when I put in the first ACT2600. The clutch disengagement point would keep dropping further and further to the floor till the point where it just wouldn't disengage as the day went on but it would be fine after sitting around for a few hours. One day while out driving I pushed in the clutch and heard a loud clunk sound followed by the good old handful of bolts in a coffee can sound. I got the car towed home and pulled the trans thinking that maybe I blew a gear stack. I noticed that the fork pivot point where the slave rod pushes was all the way to the pass side, I grabbed the fork and was able to move it around quite a bit more then I should of been able to. Upon removing the trans I found that the fork had bent then broken about half an inch past the pivot ball. The clunking sound was the fork tine end smacking against the PP and bell housing, it dinged both up a bit but nothing fatal. I got a new fork and put the car back together, wala, problem fixed, or so I hope. The 2600 is gone along with my 7-bolt so with the new build I ordered a DEVO twin disk clutch which came with a new fork modified to work with the taller hat height of the pressure plate.


The DSM fork is fine for stock and lower spring force clutches but when you start getting into 2600 to 3200 plates the fork just bends from the stress.

I have tried to get a hold of Taboo to see if I could get his design but he never returned my emails. I would love to find one of his forks and copy it or just make a new design of my own some time.
 
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