So I know I'm new, but I have done tons of research and watched countless videos trying to figure out my problem. Here's the rundown, I just bought this 03 G35 and while running the clutch is very sticky and will not come back up after depressing it. It will not allow the car to go into gear at all, but if I shut the car off put it in gear and start the car it will go just fine. The research I've done points to the slave cylinder, but the guy I bought it from swears the clutch itself is bad. But if the clutch was bad it shouldn't go in gear when you fire the car up? Any input would be greatly appreciated! Thanks

 

You could always inspect the clutch fork actuator arm with an inspection mirror without jacking up the vehicle. Replicate the problem, have someone work the clutch pedal while you lay down on the side of the vehicle with a.powerful flashlight and an inspection mirror. Observe the distance the clutch fork arm moves while it's having problems and again when it's not having problems.

If it appears the slave cylinder piston isnt moving the clutch arm then the problem is likely the hydraulics (replace clutch master cylinder and operating slave cylinder at the same time along with a full fluid flush, don't just try to replace one component). If the clutch fork is moving the same distance regardless of the problem being present then it's likely an issue with the clutch itself.

 

Thank you for the response Cleric! I will check that out first thing saturday and will post what I find. I think I may have worded it a little wrong though, it is permanently stuck like this while the engine is on i press the clutch and cannot get it into gear and hear a faint kind of whirring sound when the pedal is fully to the floor. Only way I can get it to move is by shutting the car off putting it in gear then starting it while in gear, it lurches forward while the motor cranks and once it fires up it moves great in that gear but I cannot shift from that gear.

 

Ahh that should he an easy one to figure out then since it has the problem all the time. To make life easier just get the car on jackstands so you can visually inspect the clutch slave cylinder piston easier. Hopefully it's just a failed CMC/CSC and if it won't actuate you should try bleeding it first. Might just have a leak.

 

That's what I'm hoping for!! I will update on this tomorrow around noon, If I find the problem I may shoot a quick video of the problem and the fix hopefully help someone else out down the road.

 

Ok problem found and in the process of fixing it. Master and slave cylinders were fine and working properly, so I pulled the tranny along with the clutch, flywheel, and throw-out bearing. Clutch didnt look horrible but was definitely in need of a new one, flywheel had a ton of slop in it not sure if that's normal with a Dual Mass. So anyway after inspecting the throw-out bearing and sleeve I found the bearing had actually torn apart from where it presses on the sleeve and was at a huge angle, I assume this was the cause of why the clutch would not disengage at all. Ill be throwing the new one in next weekend and will update again once I get it all back together.

 

The dual mass flywheel will have ROTATIONAL play in it yes, that's how it's designed to work. You can measure it in place on the vehicle, turn it all the way until you feel it bottom out against the travel spring, just put a little tension on the travel spring and make a sharpie mark across the two halves of the flywheel. Now turn it the other direction until you feel the opposite travel spring, make another sharpie mark. The two marks should be less than 24mm apart (radial measurement), if it's more the DMFW is shot.

Next push on one side of the DMFW, take a measurement of the distance back to the engine, push on the OTHER side of the DMFW, take another measurement from the initial side (thrust measurement) it should be less than 1.3mm, if it's more the DMFW is shot.

 

Thanks for the info on that DMFW, tested it and sure enough it had right under 36mm of travel. It was replaced with an 18lb lightweight flywheel (Here comes the chatter) and an exedy oem style clutch. Throwout bearing also got replaced with a pre-pressed bearing on sleeve, everything is back together except for my starters lug for the power wire had snapped off at some point during this ordeal. So new starter will be installed this weekend and should be driving the G35 for the first time since I've owned it! I will also upload pics of the DMFW, Clutch, Pressure plate, and the torn Throwout bearing for informative purposes.