Clutch slipping after driving 650+ highway miles yesterday

[diab0lus]

'05 LGT Wagon 5MT - 151k miles on engine / ~161k on transmission

 

I've observed multiple symptoms and would appreciate any help in diagnosing the issue. A few things to note that preceded yesterday:

 

• Current clutch is a Competition Stage 2 clutch (model 15026-2100)
  
• Clutch listed above was installed in 2015 in a salvage transmission (about 10k more miles than the original transmission) then replaced the failed transmission (TOB).
  
• The reason for a stage 2 clutch is the engine has a Cryotune'd BNR VF40-EVO16G/TD05H, which is probably making around 290 AWHP (guessing) and was installed about 3-6 months prior to the transmission failing
  
• I actually don't drive very much. There has only been about 30k miles put on the car in the four years since the new transmission and clutch were installed - mostly city driving
  

 

Yesterday, the car was loaded with 3 people, a large dog, three medium suitcases, and about 100 lb of other cargo. At about 400 miles into the trip we stopped at a rest stop for a few minutes. I noticed the clutch took a moment longer to engage when backing out of the spot, but otherwise things seemed normal. Less than an hour later the clutch went to the floor and stayed there. I had to use my foot to pull the clutch back up every time I would shift. The clutch seemed to engage fine. After a little while the clutch stayed up, but seemed stiffer than before and had no play at the top. I took a wrong turn and ended up in stop-and-go city traffic. At this point I noticed some clutch slippage, and had slow take off in first gear from a stop, and engaging second exhibited a noticeable RPM mismatch between the engine speed and wheels that took about 1-2 seconds to sync up. We managed to get back on the highway. I think we were probably 500 miles into the trip at this point. The stiff pedal, clutch slipping problem continued to worsen for the last 150 miles - I could cause the clutch to slip in 4th gear at highway speeds by accelerating quickly. Once I got home, I crawled the car into a parking spot and went to sleep, hoping it was just overheated.

 

Today I checked the fluid reservoir by the firewall. It looks honey colored and the compartment is full. I decided to take it around the block to rule out overheating. Clutch pedal still stiff with no play. The transmission slipped right away and seemed to get worse with each use. I literally made three turns around a city block and parked in front of my house.

 

Is it time for a new clutch or could it be something else? Too much water in the fluid? Slave cylinder?

 

Thanks!

Edited August 5, 2019 by diab0lus
Adding detail

[whitetiger]

yep, clutch is done, or the TOB is failing/jammed up and preventing the clutch from full engaging.

[diab0lus]

yep, clutch is done, or the TOB is failing/jammed up and preventing the clutch from full engaging.

 

Thanks. I expected this clutch to last more than 30k miles, but tbf I do mostly city driving, so there is a fair amount of additional wear per mile on it because of that.

 

I had a TOB issue with the first transmission in this car and it presented itself with some grinding noises before it failed completely. I'm not hearing any noises atm.

 

I guess I'm looking for clutch recommendations that can handle 350 crank hp. The competition clutch definitely requires more pressure to disengage, and grabbed really well until yesterday, but I'm open to suggestions.

[whitetiger]

the TOB can fail in a number of different ways which exhibit different symtoms. im not saying with certainty that it is the TOB, just dont assume its not since its not behaving like it did the last time it failed. either way, the trans needs to come out and the clutch/TOB inspected. along with your replacement, look in to the TSK3 kit to help protect your trans snout.

[diab0lus]

along with your replacement, look in to the TSK3 kit to help protect your trans snout.

 

Thanks for the suggestion. I ordered the TSK3 snout kit. I wish I would have known about that 4 years ago because I would have installed it at that time.

 

My mechanic said it sounds like the clutch plate material debonded and got stuck, which is why the pedal stuck down, then it broke loose and the pedal started working again, but with a lot of slippage.

 

Now I'm trying to figure out if I just need a new disc or also need to replace the pressure plate.