What is "adjustable" about an adjustable master?
Thread Starter
TECH Apprentice
Joined: Mar 2002
Posts: 357
Likes: 0
From: Newfoundland, Canada
What is "adjustable" about an adjustable master? And no S&M cracks huh? <img border="0" alt="[devil]" title="" src="graemlins/gr_devil.gif" />
There's a new clutch in my near future and I've read dozens of posts about, depending on which clutch you go with, the need for the adjustable master cylinder. But NO where in these posts did it say what the damn thing is meant to adjust! Soooo...what does this thing do and why would I want one? <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
There's a new clutch in my near future and I've read dozens of posts about, depending on which clutch you go with, the need for the adjustable master cylinder. But NO where in these posts did it say what the damn thing is meant to adjust! Soooo...what does this thing do and why would I want one? <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
The Bull
Joined: Jun 2002
Posts: 3,578
Likes: 2
From: Grand Rapids, MI
Re: What is "adjustable" about an adjustable master? Bill,
Clutches of old (cable style) always had a way to dial the throw of the cable in and out. That would preadjust the leverage required for the throw out fork. On the T56 for our cars there is no throw out fork, all of this is done hydraulically. As a result the tolerance stackup of the flywheel, clutch assembly and the slave cylinder from the back of the motor to the face of the transmission will vary greatly from vendor to vendor.
One way to solve this is to shim the difference in thickness between the slave and the transmission. But this is a pain in the ***, especially when it takes a good hour to put the trans in, let alone take it out.
As a result McLeod came out with the adjustable master. When you take the stock master you will see that it's a fixed length with no adjustments. The McLeod adjustable simply has a thread on the end with a ball swivel tie rod end. To adjust the throwout position and the sweet spot for engagement you simply turn the rod end. As a result the stroke is lengthened or shortend. Because it's all hydraulic the displacement of the fluid will cause the slave to move and take up any tolerance issues and slack.
It's really that simple. My opinion is that hydraulic clutches are a pain in the *** to service. But they are pretty damn good once you get over all those little details.
Clutches of old (cable style) always had a way to dial the throw of the cable in and out. That would preadjust the leverage required for the throw out fork. On the T56 for our cars there is no throw out fork, all of this is done hydraulically. As a result the tolerance stackup of the flywheel, clutch assembly and the slave cylinder from the back of the motor to the face of the transmission will vary greatly from vendor to vendor.
One way to solve this is to shim the difference in thickness between the slave and the transmission. But this is a pain in the ***, especially when it takes a good hour to put the trans in, let alone take it out.
As a result McLeod came out with the adjustable master. When you take the stock master you will see that it's a fixed length with no adjustments. The McLeod adjustable simply has a thread on the end with a ball swivel tie rod end. To adjust the throwout position and the sweet spot for engagement you simply turn the rod end. As a result the stroke is lengthened or shortend. Because it's all hydraulic the displacement of the fluid will cause the slave to move and take up any tolerance issues and slack.
It's really that simple. My opinion is that hydraulic clutches are a pain in the *** to service. But they are pretty damn good once you get over all those little details.
TECH Resident
Joined: Jul 2002
Posts: 958
Likes: 0
From: Mentor, Ohio
Re: What is "adjustable" about an adjustable master? The adjustable parts is the rod that controls the distance traveled within the hydraulic part of the cylinder. You can adjust the height of the point of engagement of the clutch pedal; therefore, changing the amount of clearance between the clutch disk and the flywheel. Without having enough clearance between the disk and flywheel, you will have difficulty engaging the shifter into a gate. Many people don't realize why theres a problem engaging a gear, so they pull/push harder until it goes in. This DESTROYS your synchros and the trans in general. I think when upgrading to a stronger clutch(much higher clamping force of the pressure plate) there is a need for more hydraulic pressure to disengage the plate. The way to do this is to increase the available distance the cylinder can travel; therefore, needed an adjustable cylinder.
TECH Resident
Joined: Jul 2002
Posts: 958
Likes: 0
From: Mentor, Ohio
Re: What is "adjustable" about an adjustable master? I don't know the deep details. I know that having the pedal catch to close to the floor can sometimes make it not have enough clearance. Mine is set at about 2-3 inches off the floor. Go here and ask Mikey.
www.rapidmotorports.com
www.rapidmotorports.com
