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  #1 (permalink)  
Old 04-21-2015, 01:15 AM
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Default Hydraulic clutch set up

Have spent a few days now disconnecting everything to pull the motor and gearbox out after being unable to operate the clutch after it was bled. (TR6060 on the back of a VE LS3).

The master cylinder / pedal stroke is fine, it discharges a full column of fluid when not connected and again through the bleed valve on the slave cylinder when connected.

The pedal is basically hard once the bleed valves are locked off and is not able to be depressed.

There is about 3mm float on the pedal when unloaded and the (Willwood 7/8") master cylinder push rod has a small amount of play.

As I understand it from a day of running around today, the thrust bearing must be compressed when the gearbox is installed and then extends towards the engine to engage with the pressure plate fingers and the friction plate.

There is no clearance required as far as I know between the pressure plate fingers and the thrust bearing.

As best I can tell, measuring 3 different ways, the thrust bearing is compressed around 10mm from its spring loaded at rest position.

If (????) the info I have is correct and the thrust bearing needs to be further compressed to be able to operate once the clutch pedal is depressed how far forward does the slave cylinder need to be moved forward..?

Look forward to any advice that might be available.


With thanks

Chris
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Old 04-21-2015, 01:29 AM
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Chris,

What bellhousing? and what flywheel?

The throwout bearing has a "stroke" of 10.5mm as per Holden SI.

So if the bearing is back 10mm from it's unloaded position, technically it should work.

Can you move the pressure plate fingers?

What is the clamping force? How does Centreforce rate the pedal feel?
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Last edited by Gaz64; 04-21-2015 at 02:16 AM..
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Old 04-21-2015, 04:34 AM
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Chris, Bearing remains in contact with clutch fingers all the time, with 14 - 17mm pre-load. At 10mm you are at risk of blowing the slave cylinder apart. Sounds like air in the system. Can be difficult to purge. If you have a remote bleeder....just leave the bleeder open over night ( elevated ) . Make sure MC can vent. Has worked for me when all else has failed.

Last edited by muzzza; 04-21-2015 at 04:39 AM..
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Old 04-21-2015, 06:34 AM
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Quote:
Originally Posted by muzzza View Post
Chris, Bearing remains in contact with clutch fingers all the time, with 14 - 17mm pre-load. At 10mm you are at risk of blowing the slave cylinder apart. Sounds like air in the system. Can be difficult to purge. If you have a remote bleeder....just leave the bleeder open over night ( elevated ) . Make sure MC can vent. Has worked for me when all else has failed.
Muzza is right you need between 14-17mm preload or you will blow the seal out. I know, I did it on the Supercar, same setup. You can buy a spacer, I think there is a 6mm one available. If you can't get one in Sydney then NPC in Brisbane have them.
Alternatively you could make one out of a piece of 6mm plate... Don't forget the longer bolts.
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Old 04-21-2015, 03:36 PM
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Perfect gents.. many thanks.

Will get a new slave cylinder as its possible this one has been damaged as well as a 6mm spacer.

Appreciate the advice.

Chris
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Old 04-21-2015, 03:53 PM
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Quote:
Originally Posted by Gaz64 View Post
Chris,

What bellhousing? and what flywheel?

The throwout bearing has a "stroke" of 10.5mm as per Holden SI.

So if the bearing is back 10mm from it's unloaded position, technically it should work.

Can you move the pressure plate fingers?

What is the clamping force? How does Centreforce rate the pedal feel?
hi Garry,

I got the LS3 and Tremec from Prestons in VIC as a kit, its all VE Commodore (HSV) standard set up.

The pressure plate fingers are not movable when the clutch is bolted in plate. The pedal is simply rock hard, once the play in the MC pushrod has been taken up.

While I bled the MC and slave, it may require more time to fully resolve any air pockets as per Muzza's advice.

Chris

Last edited by SydneyChris; 04-21-2015 at 04:32 PM..
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Old 04-22-2015, 01:37 AM
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Hi Chris,

If your pedal is rock hard, I would consider the system has been bled correctly.

So if the engine, bellhousing and transmission is all HSV (LS3, T56), then I wonder why you can't depress the pedal.

How long has the clutch been assembled on the flywheel prior to first attempt of a "rock hard" pedal?

I have had cars with clutch plate stuck to pressure plate and/or flywheel.

That's why I asked whether you can move a pressure plate finger with your hands or a small prybar etc.

I'm interested in the production date of the clutch plate 13-05-02?

Your thoughts?

Gary
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Last edited by Gaz64; 04-22-2015 at 01:43 AM..
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Old 04-22-2015, 04:49 AM
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Sounds dumb............but is clutch plate installed right way around ?? Master cylinder valve opening when pedal is released ? muzzza

Last edited by muzzza; 04-22-2015 at 01:55 PM..
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Old 04-23-2015, 04:14 AM
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Not sure if this exactly fits your situation but I found this on a website here GM LS7 Clutch & Flywheel Package for ALL LSx Applications - Tick Performance, Inc.

"If you've lightly modified your LS1/LS2/LS3 or LS6 engine and you need a stronger clutch but don't want to give up factory-stock driveability, this GM LS7 Clutch is right up your alley! Using the same clutch disc and pressure plate that C6 Corvette Z06 is equipped with, this GM Performance clutch kit was engineered to deliver maximum reliability and durability, as well as long-term dependability. Ideal for street and mild strip use. This kit includes everything needed to install in any LS1/LS2/LS6 application: clutch disc, pressure plate, conversion flywheel, and GM flywheel and pressure plate bolts.

RAM 19.5LB Aluminum Flywheel upgrade includes ARP Flywheel & Pressure Plate bolts.

LS6 and LS2 powered CTS-V applications require the use of the Katech CTS-V Slave Cylinder Spacer, sold separately.

LS1 Camaro & Firebird, LS1 & LS6 Corvette, and LS1 & LS2 GTO all use the 14061685 pilot bearing. Every other application uses the 12557583 pilot bearing. 26SPLCAT fits all applications."
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Old 04-23-2015, 04:46 AM
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hi Garry..

(and yes Muzza, it one of those, should work but doesnt issues, lucky me.. lol)

I managed to speak with Mal Wood, the Tremec importer after my last post. He advised 10mm preload is not sufficient for the slave cylinder, and more than likely the one I had popped once the pedal was pressed the first time. (Many thanks to the engine builder who put the thing together, but was apparently accustomed to a LS1 / T56 set up)..!

The clutch plate checks out ok, has been installed for six months or so. I also had the pressure plate tested while it was out. Will get the new thrust / slave cylinder, including the spacers to increase preload to 16mm and take my time with the bleeding.

Will let you know in the next few days if Australia post comes through..

Cheers

Chris
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Old 04-23-2015, 04:46 AM
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Wow, so much info on the web...not sure how much of it is accurate. For info on shims look here...
Does YOUR Clutch Setup need a Shim? - LS1TECH

Found some pics here http://ls1tech.com/forums/manual-tra...good-tech.html

Last edited by Auswallaby; 04-23-2015 at 05:19 AM..
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Old 04-25-2015, 08:08 PM
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thanks Auswallaby,

I had been using the shaft length to check the distances... after measuring against the bell housing and the matching face on the gearbox it seems its a different story, as the turned down section of the gearbox input shaft does not fully insert into the mating section on the flywheel.

The measurements I now have:

A: Bellhousing to pressure plate fingers - 64mm
B: Gearbox face to thrust bearing - 73mm (with a 6mm spacer installed)

Pre load... 73 - 64 = 9mm

I will need to get another 6mm spacer to get the preload to the spec range of 14-17mm or see if I can get a longer slave cylinder set up.

The bellhousing is 150mm... not sure what happened with this part, but it seems its a little longer than it should be or its made for a manual clutch / fork set up.

The thrust bearing / ss unit is 90mm when measured, sitting on the bench.

Look forward to any thoughts or (additional) obvious errors.

Cheers

Chris

Last edited by SydneyChris; 04-26-2015 at 03:13 AM..
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Old 04-25-2015, 08:10 PM
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double post.. moderators delete..?

Last edited by SydneyChris; 04-26-2015 at 03:14 AM..
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Old 04-29-2015, 01:01 AM
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The plot still thickens on this one.. !!

Decided to get rid of the Centreforce clutch as they are apparently heavy and very noisy. Got the GM standard clutch and pressure plate to match the LS3 / TR 6060 combination, but as per the included pic the pressure plate wont compress all the way to meet the flywheel.

Is it possible I could need to swap the flywheel over as well..?

With thanks

Chris
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Last edited by SydneyChris; 04-29-2015 at 01:35 AM..
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Old 04-29-2015, 02:08 AM
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in theat first pic something does not look right the presure plate should be all the way to the fly wheel but in the pic you can see a 1/2 gap and the bolt threads ?
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Old 04-29-2015, 02:27 AM
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I can see what's wrong.

The Centreforce pressure plate matches the flywheel you have.

The factory style pressure plate needs a stepped flywheel.

So what I'd do now is assemble the whole "Centreforce assembly, and assemble the correct flywheel with a factory clutch.

Then with each on a bench, measure the depth from the flywheel mounting flange to the tips of the PP fingers.
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Last edited by Gaz64; 04-29-2015 at 02:30 AM..
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Old 04-29-2015, 03:25 AM
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Thanks for the confirmation Garry.

Will get a new flywheel fingers crossed they can ship before the weekend.

Cheers

Chris
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Old 04-29-2015, 04:53 AM
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It looks like you need a flywheel that has standoffs. I know the ls7 style has that style, maybe the ls3 is the same.

Edit. Beat me to it gaz....
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Old 05-01-2015, 12:02 AM
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OK.. have the LS3 / LS7 style flywheel, which comes in two parts.. ! and measures approx 120mm high as pictured.

The equivalent measurement for the Centerforce set up is 95mm, a difference of 25mm.

The effect would be a pre-load crush of 28mm on the slave cylinder bearing, which exceeds the 14-17mm recommended.

The SS stands at 90mm overall when measured on the bench.

The bell housing is 150mm long overall and its not going to be possible to change that part as the engine and gearbox mounts are already made up to suit.

Is there a shorter SS available... Look forward to any advice.

With thanks

Chris
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Old 05-01-2015, 12:28 AM
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Hi Chris,

Can you show pics of the factory flywheel on it's own?

I would consider the much lower height of the centreforce assembly as to the SOLE reason your pedal was rock hard. The throwout would have been at the end of it's mechanical travel.

I'd be requesting some fixup from where your bought the centreforce clutch and flywheel from.

I can't see it being a case of adding a 25mm spacer under the throwout, you might not be able to bleed the system.
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Last edited by Gaz64; 05-01-2015 at 01:21 AM..
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