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Potential Clutch Slipping?

PostPosted: Fri Jul 22, 2016 10:17 pm
by Lane
G'day,

Just bought an '07 GT B Spec Liberty and on the freeway home in 5th or 6th gear full throttle at around 2800rpm -3000rpm the revs would rise ever so slightly (200 -300rpm only) with no rise in speed.

There is no shudder, noise or vibration just a very subtle rise on the tacho, if you weren't watching you wouldn't notice it, the car had a new clutch 18000kms ago, I have the receipt right here in front of me.

Is there anything else anyone can think of it might be besides the clutch?

Thank you.

Re: Potential Clutch Slipping?

PostPosted: Sat Jul 23, 2016 9:20 am
by Manaz
Try it again from lower speed up a hill in a set gear - loading it up will really test it. The increase of speed an revs should be linear (ie if revs are 2,000rpm at 30km,h, they should be 4,000rpm at 60km/h and 6,000rpm at 90km/h) - unlike in a car with a torque converter auto, there should be NO slip at all in a manual.

Re: Potential Clutch Slipping?

PostPosted: Mon Jul 25, 2016 8:08 pm
by Lane
Fixed another issue, the hose clamp from the intercooler to the throttle was loose and leaking under boost.

Now that is done up tight the car is making full power and clutch is slipping much more.

Crazy to think that it only lasted 18k.

Does anyone have an opinion on the Exedy Heavy Duty clutch here? http://www.ebay.com.au/itm/181917328713 ... EBIDX%3AIT

Or are there better options for the price? I will only be running 200kw atw eventually so no need for anything over the top.

Re: Potential Clutch Slipping?

PostPosted: Tue Aug 23, 2016 12:41 pm
by Lane
For what it's worth I adjusted the clutch pedal limit switches inside the car, the outer one was adjusted too far in and preventing the clutch from full travel.

Still slips slightly but is much more manageable and I can even drive in S mode now.

Changing clutch Friday.

Re: Potential Clutch Slipping?

PostPosted: Tue Aug 30, 2016 12:41 pm
by Lane
So, I reluctantly changed the clutch plate on Friday but on pulling out the old clutch was immediately disappointed as it had plenty of meat left on it, I put in the new one anyway which was an Exedy heavy duty clutch complete with new pressure plate and bearing, the flywheel looked mint with no hot spots and still had the machining lines from the last clutch change 12 months ago, roughed it up with some emery and cleaned it up.

I checked the driveshafts as apparently they can slip out and give similar symptoms.

I changed the slave cylinder and bled the system, still no luck, it slips as soon as I try to put any real power down, in I mode it almost does not slip at all.

Anyone ever had symptoms of a slipping clutch yet turned out to be something else?

How much free play do you guys have in your pedal before it pushes the master cylinder rod?

Running out of ideas and any input would be much appreciated,

Cheers

Chris.

Re: Potential Clutch Slipping?

PostPosted: Thu Sep 08, 2016 11:04 am
by Lane
Replacement flywheel installed and all ok now.

Despite being machined twice by qualified shops, it was the culprit.

Re: Potential Clutch Slipping?

PostPosted: Thu Sep 08, 2016 1:57 pm
by jslayz
Great news!!

Re: Potential Clutch Slipping?

PostPosted: Thu Sep 08, 2016 2:20 pm
by BillyCorgi
Chris,

It is good news that is sorted.
Sorry that you had the shop rip open a good centre diff.
It is all rebuilt now.
Cheers!

BTW, your old diff reassembled at 124.70 to 124.75mm, meaning the replacement was an exact size!
Cheers!

Re: Potential Clutch Slipping?

PostPosted: Fri Sep 09, 2016 8:06 am
by Lane
Cheers BC good to know the size was spot on!

Re: Potential Clutch Slipping?

PostPosted: Fri May 19, 2017 7:56 pm
by Shaheenis
Chris,

Did you get that clutch in the link? How did it go? Looks like I need a new one so doing some research.

Cheers,

Re: Potential Clutch Slipping?

PostPosted: Sat May 20, 2017 5:42 am
by Lane
Yep, no complaints, took a couple of thousand kms to bed in properly and was a bitch to drive for a while.

Exedy is a well known brand so you can't really go wrong, if you have none or very little modification plans I would stick with a regular duty clutch.

I ended up with a lightened flywheel too.