Hydraulic clutch setup for 4 speed

Topsterguy · August 30, 2012, 08:59:58 PM

I've got a 350 crate motor and a BW Super T-10 4 speed in my 40 pickup, and currently used a regular standard bellhousing and clutch fork with a hydralic clutch and slave. Turns out the geometry between the slave cylinder shaft and the fork isn't quite right so there is slight pressure on my clutch all the time.
So, I'm looking for an alternative setup for the clutch, still hydraulic but so that all the parts "match", and even possibly a hydraulic throwout bearing. Anyone got suggestions, ideas, what did you do on yours? Thanks!

GPster · August 31, 2012, 07:59:36 AM

Could you use a '59 - '64 (?) bellhousing and thow-out fork. This would include flywheel, starter clutch etc. Maybe your bellhousing could stand re-drilling to move thr pivot for the fork to get the movement correct. I think that throw-out forks are related to the clutch, flywheel size. Could you have mis-match of parts? GPster

Topsterguy · August 31, 2012, 11:01:21 AM

Quote from: "GPster"Could you use a '59 - '64 (?) bellhousing and thow-out fork. This would include flywheel, starter clutch etc. Maybe your bellhousing could stand re-drilling to move thr pivot for the fork to get the movement correct. I think that throw-out forks are related to the clutch, flywheel size. Could you have mis-match of parts? GPster

The mismatch of parts is possible - I pretty much used what I had and that seemed to work together. :?

wayne petty · August 31, 2012, 08:41:02 PM

i don't know which Mix of parts you are using...

let me explain about hydraulic slave cylinders used with most clutches..

as the thickness of the clutch disc is worn thinner.. the pressure plate moves down and the fingers or diaphragm fingers move closer to the throw out bearing ...

this pushes the fork back on the bearing retainer.. levering the slave cylinder end forward... sinking the piston deeper into the slave cylinder bore...

if the PUSH ROD IS TOO LONG... you will be bottoming out the piston in the slave cylinder....

figure out a way to SHORTEN the slave cylinder push rod...

measure what you have currently .. depending on how much pressure the slave is exerting on the clutch fork...

if your slave is currently bottomed.. you might need to loose 1/2 to 3/4" ... but this also depends on how much clutch friction material there is above the top of the rivets..

take 1/2" off the push rod... make sure there is a return spring pulling the clutch pedal upwards... this will allow the spring tension of the cover fingers to push the slave back in but NOT bottom it out.. the spring will pull the pedal up..

this makes the slave cylinder self adjusting...

there is a big spring in the slave cylinder that keeps the push rod tight against the clutch fork....

i don't know if this will help...

i may come back and repost more info later tonight...

Topsterguy · August 31, 2012, 08:47:41 PM

Quote from: "wayne petty"i don't know which Mix of parts you are using...

let me explain about hydraulic slave cylinders used with most clutches..

as the thickness of the clutch disc is worn thinner.. the pressure plate moves down and the fingers or diaphragm fingers move closer to the throw out bearing ...

this pushes the fork back on the bearing retainer.. levering the slave cylinder end forward... sinking the piston deeper into the slave cylinder bore...

if the PUSH ROD IS TOO LONG... you will be bottoming out the piston in the slave cylinder....

figure out a way to SHORTEN the slave cylinder push rod...

measure what you have currently .. depending on how much pressure the slave is exerting on the clutch fork...

if your slave is currently bottomed.. you might need to loose 1/2 to 3/4" ... but this also depends on how much clutch friction material there is above the top of the rivets..

take 1/2" off the push rod... make sure there is a return spring pulling the clutch pedal upwards... this will allow the spring tension of the cover fingers to push the slave back in but NOT bottom it out.. the spring will pull the pedal up..

this makes the slave cylinder self adjusting...

there is a big spring in the slave cylinder that keeps the push rod tight against the clutch fork....

i don't know if this will help...

i may come back and repost more info later tonight...

Thanks Wayne! The rod is threaded on the fork end for adjustment, so it goes through a "washer" then through the fork end. For adjustment I back off or wind in the locknut, so the lngth shouldn't matter, right? Larry

wayne petty · September 01, 2012, 01:01:03 AM

sounds good...

the spring in behind the slave cylinder piston should keep the tension up so the rod does not drop out..

you might want to use something like some Tie wraps in a loose configuration to catch the rod for the first week or two.. just in case it falls out.. its no fun walking for miles back down the highway looking for it.. and when you have already walked a mile back from your car.. you hear it go by stuck in a big rig tire... clap.. clap.. clap.. clap..

don't ask how i know about that..

the slave cylinder piston should not have to be totally retracted... so take the RETURN spring off the clutch fork... let the return spring on the clutch pedal return the pedal upward...

i am hoping that this will work out.. you might want to take a decent guess at the stroke of the slave if you can get the dust boot off for a second.. see how much distance there is from the inside of the snap ring and the front side of the piston..

you are still going to need a full stroke on the slave cylinder.. but..i don't want the resting area of the piston so high that the piston hits the stop ring before the clutch disengages...

you might want to measure the length of the stroke on the slave cylinder action.. when the pedal is depressed...

sorry i did not get this additional info in earlier.. i had company and then had to leave for an overnight repair job..

Topsterguy · September 01, 2012, 01:22:20 AM

Quote from: "wayne petty"sounds good...

the spring in behind the slave cylinder piston should keep the tension up so the rod does not drop out..

you might want to use something like some Tie wraps in a loose configuration to catch the rod for the first week or two.. just in case it falls out.. its no fun walking for miles back down the highway looking for it.. and when you have already walked a mile back from your car.. you hear it go by stuck in a big rig tire... clap.. clap.. clap.. clap..

don't ask how i know about that..

the slave cylinder piston should not have to be totally retracted... so take the RETURN spring off the clutch fork... let the return spring on the clutch pedal return the pedal upward...

i am hoping that this will work out.. you might want to take a decent guess at the stroke of the slave if you can get the dust boot off for a second.. see how much distance there is from the inside of the snap ring and the front side of the piston..

you are still going to need a full stroke on the slave cylinder.. but..i don't want the resting area of the piston so high that the piston hits the stop ring before the clutch disengages...

you might want to measure the length of the stroke on the slave cylinder action.. when the pedal is depressed...

sorry i did not get this additional info in earlier.. i had company and then had to leave for an overnight repair job..

LOL, okay, thanks Wayne! I'll have a re-look at it all! Larry

Topsterguy · September 18, 2012, 10:36:02 PM

We're pulling the trans in the next few days, but I'm thinking of a hydraulic throwout bearing setup , either after market or OEM, and get rid of the fork completely. Any ideas on what's best and most cost efficient that's available? Not really familiar with this stuff so help's appreciated!

wayne petty · September 19, 2012, 10:15:09 AM

there is an important article that i was looking for as you need to measure the distance from the clutch fingers to the transmission mounting surface for sizing the proper hydraulic clutch that fits on the input shaft if thats what you are doing.

this is from one of the manufacturers of center mounted clutch slave cylinders...

http://www.ramclutches.com/Instructions/RAM%20Hyd%20Setup.htm

here is one i ran across by accident...

http://www.circletrack.com/drivetraintech/ctrp_0404_bellhousing_alignment/viewall.html

here is a more in depth look at the misalignment issue.

http://www.circletrack.com/drivetraintech/ctrp_0607_bellhousing_alignment/

i figured out that one can also install a long stud in the flywheel to crank bolt holes.. use some jam nuts and flat washers to be able to measure the distance from the transmission centering ring with feeler gauges instead of a dial indicator...

enjenjo · September 19, 2012, 10:47:10 AM

I've had good luck with Tilton in the past with no issues. Get it set right, and you can forget it.

Topsterguy · September 19, 2012, 09:25:52 PM

Quote from: "wayne petty"there is an important article that i was looking for as you need to measure the distance from the clutch fingers to the transmission mounting surface for sizing the proper hydraulic clutch that fits on the input shaft if thats what you are doing.

this is from one of the manufacturers of center mounted clutch slave cylinders...

http://www.ramclutches.com/Instructions/RAM%20Hyd%20Setup.htm

here is one i ran across by accident...

http://www.circletrack.com/drivetraintech/ctrp_0404_bellhousing_alignment/viewall.html

here is a more in depth look at the misalignment issue.

http://www.circletrack.com/drivetraintech/ctrp_0607_bellhousing_alignment/

i figured out that one can also install a long stud in the flywheel to crank bolt holes.. use some jam nuts and flat washers to be able to measure the distance from the transmission centering ring with feeler gauges instead of a dial indicator...

Thanks bigtime ! I ordered the McLeod setup from Jegs. That measurement on mine was 2 11/16". I passed this thread on to the guy that does any work on my car that I don't do....mostlt the techy stuff!