Clutch fork movement ratio?
Thread Starter
Team Owner
Joined: Mar 2000
Posts: 83,383
Likes: 87
From: Boston, MA
Clutch fork movement ratio?
Hi everyone.
I'm trying to figure out if I have enough clutch fork travel for full clutch release. The tranny is in the car so I can't really measure it at the T/O bearing. The flywheel has been resurfaced twice, but I would suspect it is still within spec. To be honest I forgot to measure it.
Centerforce says I need 0.360" of movement at the T/O bearing once the bearing has made contact with the clutch diaphram.
GM says that I should have 0.700" of pushrod movement measured at the clutch fork with a properly working hydraulic system.
Now... does anyone know what ratio due to pivot ball location I have in my '87 with the doug nash 4+3 tranny? For those of you not familiar with it the front section is just a DN Super T-10 if that helps.
It looks like I need a 1:1.94 ratio or better for full release if my clutch system is working properly with its 0.700" movement.
So why am I even doing this? I had issues with not being able to fully release the clutch resulting in a burnt centerforce unit. I replaced the clutch and two days ago replaced the 183k mile old clutch hose & slave cylinder and I am just trying to do some extra work to make sure things are right.
I'm trying to figure out if I have enough clutch fork travel for full clutch release. The tranny is in the car so I can't really measure it at the T/O bearing. The flywheel has been resurfaced twice, but I would suspect it is still within spec. To be honest I forgot to measure it.
Centerforce says I need 0.360" of movement at the T/O bearing once the bearing has made contact with the clutch diaphram.
GM says that I should have 0.700" of pushrod movement measured at the clutch fork with a properly working hydraulic system.
Now... does anyone know what ratio due to pivot ball location I have in my '87 with the doug nash 4+3 tranny? For those of you not familiar with it the front section is just a DN Super T-10 if that helps.
It looks like I need a 1:1.94 ratio or better for full release if my clutch system is working properly with its 0.700" movement.
So why am I even doing this? I had issues with not being able to fully release the clutch resulting in a burnt centerforce unit. I replaced the clutch and two days ago replaced the 183k mile old clutch hose & slave cylinder and I am just trying to do some extra work to make sure things are right.
Drifting
Joined: Dec 2000
Posts: 1,851
Likes: 5
From: Liberal Kansas
Re: Clutch fork movement ratio? (scorp508)
I hear you on this. Although a different generation ('63) I have been trying to figure out why that with an inch of free play the clutch peddle has to be at the floor for the clutch to release. A new pressure plate and clutch disc helped but still needs most of the peddle travel to release. Things that make you go Hmmm!
