I'll try to make this as short as possible, but wont be so short

I bought a 2006 G35 Coupe with 89k km on it and a worn out clutch late fall 2013. I took the car to a shop (won't mention the name for now) to replace the clutch with a JWT clutch combo and a SS clutch line.
I went there to pick up the car so I asked to have the keys to check it out before I pay. I noticed the clutch fluid was still very yellow, I went back in asking the lady at the front desk if they changed the clutch line, she went to the shop asked the mechanic that worked on the car and he said he did for sure. I went back again to the car & checked the line coming out of the master cylinder I noticed it was still rubber & not changed. I called the mechanic out & he was very sure that he changed it and that yellow is the right colour for the clutch fluid, I asked for a bottle of the fluid he used he said "they don't sell it". After so many back & forth with him he did admit that he didn't change it and that he have it in the back. Told me to come back tomorrow and he'll do it on his break. I said F that, I asked to speak to the manager explain the situation she was very nice & apologized. She said keep the car here and it'll be ready the next day.

Picked up the car next day, drove it for less than 100km in 5 days and started having issues going into gear in the morning when cold. Had to push the shifter really hard to go into first & reverse. I installed an after market RJM clutch pedal hoping would make things better but it didn't. A week later snow started falling & car was parked. I did mention the problem to the manager she said to bring it in when I can. I didn't get the chance to do it before Christmas, early January I started it up for the first time (really cold day) and the car wont go into gear at all. Waited like an hour for the car to warm up & still wont go into gear, so I shut it off & started the car in first and while shifting to second it was very hard however I did manage to get it into gear after pushing harder on the shifter and hearing a grinding noise. I drove the car in second all the way to the shop which is less than 2km from my house.

Car stayed there for a week IIRC before they started working on it, however I was in no rush since the car is not winter driven. Eventually they dropped the tranny and the shop foreman said the guy who worked on it didn't install the pilot bushing which caused damage on the flywheel & clutch plate. So he said they will order a new JWT clutch combo & do the install for free. At this point thought this was fair & I was happy. Gave them the info of the site I ordered the clutch from and they ordered a replacement.

Took forever but clutch finally came in, they installed it and problem still there. They said my after market clutch pedal is causing the issue, so I brought them the OEM pedal back & they installed it & the problem still the same. After running many different test & whatnot they said the problem is in the master cylinder. My RJM pedal caused the MC to fail, I had no choice but to pay & replace it. Another week or so in the shop the MC was replaced. Picked up the car drove it for half hour and the clutch pedal is not bouncing back up. I took it in they said leave it here its not pressurized properly. I left there it there they called me after few days saying problem keeps happening. They bleed the system it works fine & after few drives it goes back to the same issue, they were very sure that the MC is still an issue (the brand new one) & they are gonna order another one. At this point I was running out of patience. I told them to credit me back for the MC and to order a new MC from Infiniti & I'll pay the difference but they pay for the install.

Took almost 10 days for that to come in, they install the new MC and guess what!!! same F'ing issue! The shop foreman said they are having issues bleeding/pressurizing the system. So he had to order a new tool in and that would take another week or so, so I waited again. Only reason I'm being so patient is because its winter & I really don't need the car ATM.

Finally new tool is in, they do whatever they did I got my car back running properly. Date was April 17th, 2014.

****Fast forward to last Sunday August 17, 2014.****

Driving on the highway back to Fort McMurray, going approx. 120 km/h in third shifting into forth. I clutch in & car won't go into forth, I park on the side of the highway turn the car off & notice the clutch pedal is stuck to the floor. I pull it out with my hand it goes back to normal position, however when I clutch it in only returns half way back. Tried starting the car, clutching in & it wont go into any gear. Stuck on the side of the road I shut the car off again put it in first start it while clutched in car jumps & starts moving, so I hit the highway again & kinda matched my revs & shifted from 1-3. Drove it in third all the way back into town which was only around 20km outta town. Drove straight to the shop & parked it there for the next day.

They took the car in the next day, they looked through the fork hole & I was told that my clutch is burnt. I said the car didn't slip not once, they said sir your clutch is not worn, its burnt from over heating.

The manager & shop foreman are both away. They called the manager & she authorized them to drop the tranny. I waited there while they dropped it and noticed this.




















We measured the travel of the slave cylinder with just hand pressure and it only travelled 13.8mm instead of 15.25mm which are stock specs. I'm pretty sure its gonna travel even way less with 1200kg of pressure as per JWT specs. The shop staff are convinced the damage was caused by overheat or from shifting the car previously at 6800rpm, redline is 7000rpm.

They are also very sure that there are no hydraulic issues & that everything else is working properly, even though the slave cylinder is not travelling the right distance under hand pressure. So I don't think it would even move under 1200kg.

As of right now the car is still at the shop, waiting for the manager to be back tomorrow & the shop foreman on Wednesday.

What are your thoughts on what might have happened?

 

Have you attempted to adjust the clutch MC rod ?

Went through similiar issues after recently completing a DIY 5AT to 6MT swap.

Purchased a complete used clutch pedal assembly and clutch MC and installed as set with no adjustments.

After install could not get clutch to disengage fully or was able to shift in gear and pedal stuck to bottom. Bleed out system numerous times and still a problem.

Rebuilt clutch MC and still not able to disengage clutch fully or pedal release back.

Installed a ZSpeed/Wilwood MC keeping exact rod engagement and still not disengaging clutch and pedal sticking.

Finally adjusted clutch MC rod out as far as possible while maintaining full thread engagent on clevis pin. Clutch was functional and pedal fully came back.

Couple days ago fabricated a bushing to extend clutch MC rod further and now much better clutch pedal feel and clutch fully releases closer to top of pedal travel.

 

Looks simply like a disk failure. Hard to say why that happened but it looks like a hard downshift or hard launch may have caused the linings to come off the facing or it simply could have been a bad clutch facing.

HotrodG35, You do not want to get the adjustment too tight or you will cause the clutch to slip when the car gets hot, I would highly recommend not extending the rod any further than the way we have them set up.
You can tighten it some until the clutch releases correctly but it sounds like you have gone much to far with the adjustment and it can cause your clutch to slip and burn up as the fluid will not get released back in to the master res and will cause pressure to be applied to the clutch all the time.

The best way to adjust is to have it loose enough that the clutch pedal doesn't return fully, then go in baby steps until the pedal starts to pop back up and stays up fully, At that point it is correct, Any further and your risk damage to the clutch.
What clutch are you running?