Pitufina

Ok this is the story. I have a Supercharged 08 base with the mn6. The stock clutch took a dump so my friend and I replaced it with a McLeod RXT. We checked for proper clearanced as suggested by McLeod. It was on the large side of it, but still within specs. I did the proper break in, took her to the track later on, and did a long 8hrs trip. No problem whatsoever! The smoothest transmissions shifts and light clutch I could've asked for.

Fast foward about 3k miles and the transmission is hard to put in 1st or reverse while on a complete stop. I bled the hydraulics twice within a couple of days...no change. Asked my friend who helped me install it and checked a couple of things but no change. I even installed poly shifter box bushings and aligned the shifter to no change. Yesterday I decided to use a mytivac on the reservoir and some bubbles came out. The shifting got a little better, but while driving from work the shifting became hard again. Tried the mytivac once again and it seemed like more bubbles came out BUT while trying to shift it was harder. So I did the disengament test and it did in fact moved slightly while revving the engine in 1st and reverse with the clutch pedal fully depressed!! So I was like WTF! Started pumping the clutch pedal over and over again. Opened the reservoir and could see very tiny bubbles comin up. Did that a couple more times and the shifting became manageable once again, but nowhere near how it was when I first installed it.

So what do you guys think is going on? There are no leaks, no fluid consumption and it was a change that started unexpectedly. In fact, I have been taking it really easy since it's been really hot around here and ai just dont like to beat on her during summer times.

I really would hate to tear into the drivetrain again. Even more, I'm tired of messing with the car and I'm contemplating returning her back to stock or just to keep the exhaust only.

Pitufina

Well I woke up this morning and decided to start pumping the clutch pedal repeatedly and somewhat fast. Stopped and opended the reservoir cap and tiny bubbles start flowing up from the orifice in the reservoir. Reinstalled the cap and proceeded to do the same thing again and more bubbles came out. Tested the shifting and it got noticeably better. At this point I'm just confused. I don't know if I may have air in the system and somehow the best way to remove it is to pump the pedal rapidly and remove the cap afterward iinstead of the typical pump and open the bleeder or use the mytivac.

CMY SIX

maybe your sucking air into the system?

Pitufina

That's what I'm thinking. The big question is how or why? Would it be possible to suck air without losing fluid? The only area I think that would be possible is the cap or seal. Don't know but it's odd for sure.

Pitufina

So somehow I had quite a bit of air trapped in the system. Now the shifting has greatly improved to the point that it feels back to where it was, but I experienced something weird with the clutch not fully disengaging when the car cooled down. Could it be that the master is failing? Once warmed up and after I went WOT a couple of times the engagement and shifting are almost awesome again. So I'll keep an eye on it and if I have to replace the master, I'll probably just use a Tick Performance.

schpenxel

Mine has done some weird things too. Cold, it's usually smooth as can be.. no spongy feeling. After it gets hot, it goes back to being spongy. I've bled it probably 10x.

I did find that the hose between the clutch fluid reservoir and the master cylinder was creased.. so my thought was maybe air was getting in through that or something

I decided to just replace the clutch master cylinder on mine along with the slave while I have the clutch apart. I hope that will finally give me a consistent clutch feel.

May be worth considering on yours (the master part that is)

Pitufina

I'm also thinking about the gap between the slave and pressure plate fingers. It was at the acceptable range but at the very limit, so now that the clutch has settled maybe the gap is out of specs. I think that a shim may be the cure, but I really hate the thought of taking apart again

I may order a new master and see what it does first before I dive into the pulling it apart. You are becoming an expert on removing and replacing the drivetrain on these cars.

schpenxel

I really really wish I weren't getting good at it. The good news is my torque tube bearings are still in great shape (replaced about a year ago)

Any idea what GM book time is for swapping a clutch on one of these things?

I hope you're wrong about needing to shim it.. I would probably try the new master first. They're pretty easy to change.

Remove driver fender. Disconnect hydraulic connection to slave. Unhook connection to clutch pedal. Twist the whole Master cylinder assembly maybe 30* and then it should be free.

CTD

As a suggestion if you are going to swap out the MC, Mcleod makes a replacement that is slightly larger. They claim it is adjustable, which it is however very limited. I have their MC & a RST & find the pedal just a little stiffer than my stock C6.

I've been thru clutch hell with my stroker C5 & have found the McLeod set up to work very well.

Pitufina

I didn't know they made clutch masters for the vette. Right now everything seems back to normal. I guess between having air trapped in the system and maybe a sticky clutch due to lack of beating since I've been taking it really easy for the last couple of months may have caused the issues. Ive been beating the heck out of it for the past 2 days and it's back to normal so who knows! Oh I almost forgot to mention it but I did reinstalled the pedal spring.

Pitufina

Glad to hear that the tt is not trashed.

I don't have any idea but ai keep hearing is around $1k

I decided to leave it alone and see what it does. I already found the part number for a new one, so I'll save it just in case.

rpmextra

Book time is 10.1-10.6 depending on if you have the trans cooler

here is my complete install guide
https://www.corvetteforum.com/forums...full-pics.html

schpenxel

That seems about right time wise.

Very good write up. Never mind on me ever doing one.. you pretty much got it

rpmextra

yeah save yourself all the work. the write up took as long as the job lol. the job itself ran me about 7hrs or so

schpenxel

That's moving pretty good! I think 3 hours to get it apart, 30 minutes or so to swap the clutch and 3.5 to put it back together is about right

rpmextra

Last C5 i did in and out in 3.5hours

schpenxel

Good lawd. I'd need some AC blowing on me to get even close to that

rpmextra

I've done about 7 maybe 8 of them so, I know them well I was trying to hurry i wanted my Saturday lol

Pitufina

Well the issue is back and I'm dumbfounded! I went to move the vette this morning and it didn't want to go into reverse. So I pumped the clutch pedal several times openned the reservoir and tapped the rubber line and walá...bubbles came out!! Seriously, how is it possible to get air in the system without leaking?? Can anyone smarter than me figure it out or can explain it to me?? This is just annoying and getting on my nerves!! Please help!!

schpenxel

If you find an answer.. let me know. I suspect I have (or at least had) the same problem.

If the problem is gone after I get my new master in I'll let you know