rikhek

Car is an '01 coupe with MN6 and 58k miles. Headers and intake only add ons. Car has never been dragged but has about 3,000 road course (i.e., track) miles.

Was going for a drive about 3 weeks ago and couldn't get in reverse to get out of garage. Managed to force in eventually but then very hard shifting into forward gears. Drove it a bit and it 'fixed itself' and drove fine.

A week later took it out for a 300 mile drive. About 150 miles into drive it got very hard to shift for about 20 miles but again fixed itself.

Today went out and after 150 miles it did it again but worse than ever. Got VERY hard to shift going into 4th, 5th and 6th. Could NOT get into 1st thru 3rd. Had to start from dead stops in 3rd as I was then able to use a lot of force to get it 4th, 5th and 6th. It took less force to get into 4th, less again to get into 5th and less again into 6th. However, even this took enough force I though I was going to break something....

Was able to downshift from 6th to 5th and then 4th. Again with MUCH force. Could not force into 3rd, 2nd or 1st.

Nursed it home with the following observations.

- With the engine shut off it would go into any gear smooth as butter.

- With the car rolling at driving speeds I shut the engine off and coasted but could not upshift or downshift. When car came to a complete stop with engine still off I am able to shift into any gear, smooth as silk.

- I'd come to a light and shut the car off till it turned green. While waiting with engine off put into second or third. Upon green light start the car in 2nd or 3rd with brake on and car would shudder as if clutch wasn't completely disengaged.

- Finally it got to the point that with the brake released and clutch completely depressed the car would creep forward.

When this started 3 weeks ago I thought maybe I somehow got the shift linkage in a bind and it "snapped" back into place as it 'fixed' itself.

Then I thought it was a problem with the transmission, possibly the syncro's.

Now I'm thinking it might just be clutch related.

Should also mention everything seems to work fine once I'm moving in any gear. Problem is getting it moving and being unable to change gears once moving. Clutch doesn't appear to be slipping once moving. Nailing the gas once I get it moving in whatever gear I'm in seems to put the appropriate power to the ground.

I would really appreciate your advice.....

Rick

sothpaw2

I would tell you that when I had broken keys in my trans I could not get it out of 4th gear at all, stopped with engine off or not. So I would say that's NOT what you have.

Have you checked the clutch fluid? Have you been keeping it clean? Have you ever had problems with the clutch pedal not fully returning?

rikhek

Clutch fluid level is where it was 30k miles ago. No change in pedal feel AT ALL for the same time period.

Rick

gonzalezfj

It sure sounds like the clutch is not releasing. You may get one bad sychro in a Tremec, but not 3 or 4 at the same time. I had a similar situation with my C5Z a year or so ago. It turned out to be that a piece of the clutch diaphragm spring had broken and was rattling around inside the clutch. Every now and then it would interfere with releasing the clutch and the transmission could not be shifted while the engine was running. Shifted fine with engine stopped.

If the clutch doesn't release, the sychros will not let you shift unless the engine speed and road (transmission) speed are the same.

The clutch fluid issues that many have experienced make the clutch pedal stay on the floor when you take your foot off the pedal. Not what you describe at all.

The only thing about clutch fluid may be if somehow you got air in the hydraulic system, which would prevent the clutch from releasing, but the pedal would probably feel spongy. If this is the case, you need to bleed the air out of the clutch system. That is a bitch to do in a C5 or C6. To get to the bleed valve, you need to drop the exhaust system and take out the center tunnel cover. The valve is snug and high against the bell housing on the driver's side. Bleed the same as a brake system. Use DOT 4 fluid.

Hope the above helps. Fix the clutch before you hurt the Tremec. They are expensive to fix and by manhandling the shift lever you can break a sychro retaining ring. That will cost you $500 to $1,000 to fix after you get the transmission out of the car.

Frank Gonzalez

rikhek

Frank or anyone else, I'm not really sure how the slave cylinder functions but could it be "hanging" up intermittently and not exerting pressure to release?

I'm not sure how air could have gotten into the system as it wasn't opened. Also, with air wouldn't it be causing a problem all the time?

Rick

gkmccready

When the clutch slave went in my Miata it was a royal pain and pretty flakey... you'd go to start from a stop and the clutch would fully engage only a couple of millimeters off the floor. Other times it would behave fine. At the worst it felt like it wasn't fully disengaging.

The Miata has a slave that's really easy to access and simply squeezing the rubber billows on the piston puked out a bunch of clutch fluid so it was easy to tell it was leaking -- interesting bit was with the billows full I never had to top up the master.

Since the fluid had leaked by a seal it could easily have sucked in air at some point. Heck, when the clutch started acting weird I bled it at the slave which probably got rid of some air (?) ... at the time I never noticed the billows being full. Just figured at 140Kmi it was probably time to change the clutch fluid. :-)

So, yeah, I'd check the slave... and a slave dying, atleast on my other vehicles, could let air in since it's letting fluid out...

rikhek

Wouldn't I see a loss of fluid in the reservoir? At least enought to fill up whatever is there to fill?

Rick

gkmccready

In my case with the Miata the volume of fluid that fit in the billows wasn't enough to make the master need more fluid. Once the billows filled up it seemed to seal well enough that not much more fluid ever came out of the system. But the slave was definitely dead. I'm not sure how the slave is set up on the C5 or C6, honestly, of it there's even a rubber billows/boot over the piston like on my Miata.

805Z06

It seems like the problem is with the clutch. I would have it checked out soon, to prevent more possible damage.

If they do think it is the clutch. They will probably try to bleed it first. If not, they might have to take the clutch apart.

Is there any excessive noise being heard form the transmission?

rikhek

No tranny noise. Sounds and works great once in gear and moving.

earthman01

Aluminum shift forks - a common problem in '01 and '02's. Standby for a trany rebuild. Make sure they put in the steel forks this time.

jpobrien

I had very similar issues in my 92 LT1 when I came off the track one day last fall.

I was pretty sure it was a clutch problem so I ordered a new clutch and flywheel ... and went for it.

When I got the clutch out, there was a spot on the clutch plate where one of the layers of the plate had started to come apart. You could see where the metal between the friction surfaces had bent and was rubbing on the flywheel.

I went with the Spec Stage 3 clutch and flywheel, and the clutch plate is much more beefy than what I pulled out of there. Shifts great now.

hisvett

YUP.....classic clutch issue.....my '01 did the exact same thing. I fought the idea of the clutch because (in my mind) when the clutch goes bad, it's normally gone...for good What I didn't consider was; the pressure plate was coming apart. A small piece of metal was getting wedged in the works.......keeping it from releasing the disc completely. After a time, the piece would shift and clutch travel would return to normal.

Take it to someone you trust and put it on a lift. Check out the clutch inspection hole for small parts or missing clutch fingers.

BTW, I went with the LS7 clutch/flywheel........very happy

rikhek

FYI, back on the road. New LS7 clutch, slave, master and remote bleeder and all is well. Drives great. Right at $1,370 parts and labor. This included the extra labor time for the headers.

Think the problem was the slave but not for certain. It was not leaking.

Thanks for all the help.

Rick