Slave cylinder travel
06-01-2022, 08:31 AM
#1
Slave cylinder travel I currently have a Tick 7/8" master connected to a OEM slave. I'm scheduled to take my car to a shop tomorrow morning to install a Monster LT1-S Triple to replace the Mantic 9000+ Twin. The Triple included a Howe hydraulic bearing instead of OEM, with a new bleeder line and a short adapter hose with a quick release fitting on it. I also bought a 3/4" bore from Tick. It's clear to me how to measure & shim the slave gap. However, Monster support provided the following statements regarding slave travel:
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"As far as using that master cylinder, make sure you set the gap to 0.080"-0.100" and make sure you set the overall slave travel to 0.500"-0.550" - failure to do this and over-extending the slave travel can damage the slave cylinder as well as the pressure plate."
" You will do this by adjusting your master cylinders overall throw. Essentially, you need to fully bleed the system, once done you will need to measure the slave fully compressed, then when you fully depress it and measure the slave again - the difference is the travel measurement. You want to dial this in so that it's 0.500"-0.550" of travel with a gap of 0.080"-0.100".
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Tick support said there wasn't a practical method to measure the physical slave travel. They basically said to follow the procedure at this link to find the correct slave travel distance.
Any opinions on which process to use above to minimize potential warranty issues with the clutch?
---
"As far as using that master cylinder, make sure you set the gap to 0.080"-0.100" and make sure you set the overall slave travel to 0.500"-0.550" - failure to do this and over-extending the slave travel can damage the slave cylinder as well as the pressure plate."
" You will do this by adjusting your master cylinders overall throw. Essentially, you need to fully bleed the system, once done you will need to measure the slave fully compressed, then when you fully depress it and measure the slave again - the difference is the travel measurement. You want to dial this in so that it's 0.500"-0.550" of travel with a gap of 0.080"-0.100".
---
Tick support said there wasn't a practical method to measure the physical slave travel. They basically said to follow the procedure at this link to find the correct slave travel distance.
Any opinions on which process to use above to minimize potential warranty issues with the clutch?
06-04-2022, 02:27 PM
#2
I got the car back yesterday morning. It took the shop about 6-7 hrs to complete the swap of the master bore (from 7/8" to 3/4"), slave & clutch, including us taking gap and slave travel measurements, setting the pedal rod length, checking the slave travel, & delays waiting for Monster to call us back during their lunch break. Also swapped the plastic shifter bushing with Tick's brass piece.
The other shop (not a vendor here but a local 'LS' performance shop) that installed the old Mantic chose to use the optional ARP flywheel bolts I provided, and they advised there was enough clearance. Pulling it out showed that the ARP bolt heads were rubbing against the disc springs facing the flywheel. We also found that the two bolts securing the slave cylinder were no longer tight. I'm in discussions with Mantic about having them buy it back as a rebuildable core, else a rebuild would cost me $1050. I'm leery of rebuilding it and not being able to resell it for much though.
A ) Bellhousing edge to finger distance averaged 1.6245"
B ) Bearing to tranny case edge distance averaged 1.463"
A-B= 0.1615" gap
Monster said in email "You want to dial this [slave travel] in so that it's 0.500"-0.550" of travel with a gap of 0.080"-0.100"."
So I used the Tick 0.055" shim which dropped the gap to .1065". Speaking with their lead tech on the phone he was pretty adamant that it needed to be under .100" and closer to .080" but I'd have to custom order a thinner shim which would mean more down time, and I'm hoping this is just close enough.
The slave travel measurement process was interesting. With the Howe bearing torqued down and the tranny on a tranny support, connected the slave to the master and bled the system. Shortened the clutch pedal rod as much as possible. Use a micrometer to measure how much the bearing moved while verrrry slowly depressing the pedal. If bearing travel not between .500" and .550", very gradually change rod length at pedal. It ended up that the bearing wouldn't move more than .500" when lengthening the rod. So we left it there.
Huge difference in pedal feel with those changes.
* Pedal is so soft it feels like it has a leak. I don't remember my LS7 clutch ever feeling this easy.
* Very easy to take off from a stop without any driveline judder.
* Friction point is perhaps 1-2" above the floor
* Pedal height is slightly above the brake pedal (return spring previously removed)
* I forgot to bring preferred T56 fluid, so I had them get Valvoline MaxLife ATF locally. Ordered some D4 & MTL for a future fluid change. Unsure if I'll use all D4 or a 60/40 D4/MTL. I have no idea what fluid was in it previously.
* At a stop, getting into 1st or R is not as smooth as desired. Not sure if its the fluid or if I should extend the pedal rod a few more turns. Both Tick and local tech thinks it's safe to try extending the rod a few turns and see if it improves.
* While driving, it tends to pause in neutral longer than desired during casual shifting.
* Perhaps the 500mi of stop'n'go city driving for break in will also help with minor issues above
Mantic prior to removal:
https://www.dropbox.com/s/m57unweadten0bn/2...115612.jpg?dl=0
Monster after install:
https://www.dropbox.com/s/sqvqdu8ial2kuhm/2...145336.jpg?dl=0
Checking bearing travel:
https://www.dropbox.com/s/ge0esjohjis8re6/2...164919.jpg?dl=0
ARP bolts:
https://www.dropbox.com/s/0y2x8ucvq2fagqd/2...121147.jpg?dl=0
Worn springs:
https://www.dropbox.com/s/npzopi9xa2fwjxk/2...121533.jpg?dl=0
The other shop (not a vendor here but a local 'LS' performance shop) that installed the old Mantic chose to use the optional ARP flywheel bolts I provided, and they advised there was enough clearance. Pulling it out showed that the ARP bolt heads were rubbing against the disc springs facing the flywheel. We also found that the two bolts securing the slave cylinder were no longer tight. I'm in discussions with Mantic about having them buy it back as a rebuildable core, else a rebuild would cost me $1050. I'm leery of rebuilding it and not being able to resell it for much though.
A ) Bellhousing edge to finger distance averaged 1.6245"
B ) Bearing to tranny case edge distance averaged 1.463"
A-B= 0.1615" gap
Monster said in email "You want to dial this [slave travel] in so that it's 0.500"-0.550" of travel with a gap of 0.080"-0.100"."
So I used the Tick 0.055" shim which dropped the gap to .1065". Speaking with their lead tech on the phone he was pretty adamant that it needed to be under .100" and closer to .080" but I'd have to custom order a thinner shim which would mean more down time, and I'm hoping this is just close enough.
The slave travel measurement process was interesting. With the Howe bearing torqued down and the tranny on a tranny support, connected the slave to the master and bled the system. Shortened the clutch pedal rod as much as possible. Use a micrometer to measure how much the bearing moved while verrrry slowly depressing the pedal. If bearing travel not between .500" and .550", very gradually change rod length at pedal. It ended up that the bearing wouldn't move more than .500" when lengthening the rod. So we left it there.
Huge difference in pedal feel with those changes.
* Pedal is so soft it feels like it has a leak. I don't remember my LS7 clutch ever feeling this easy.
* Very easy to take off from a stop without any driveline judder.
* Friction point is perhaps 1-2" above the floor
* Pedal height is slightly above the brake pedal (return spring previously removed)
* I forgot to bring preferred T56 fluid, so I had them get Valvoline MaxLife ATF locally. Ordered some D4 & MTL for a future fluid change. Unsure if I'll use all D4 or a 60/40 D4/MTL. I have no idea what fluid was in it previously.
* At a stop, getting into 1st or R is not as smooth as desired. Not sure if its the fluid or if I should extend the pedal rod a few more turns. Both Tick and local tech thinks it's safe to try extending the rod a few turns and see if it improves.
* While driving, it tends to pause in neutral longer than desired during casual shifting.
* Perhaps the 500mi of stop'n'go city driving for break in will also help with minor issues above
Mantic prior to removal:
https://www.dropbox.com/s/m57unweadten0bn/2...115612.jpg?dl=0
Monster after install:
https://www.dropbox.com/s/sqvqdu8ial2kuhm/2...145336.jpg?dl=0
Checking bearing travel:
https://www.dropbox.com/s/ge0esjohjis8re6/2...164919.jpg?dl=0
ARP bolts:
https://www.dropbox.com/s/0y2x8ucvq2fagqd/2...121147.jpg?dl=0
Worn springs:
https://www.dropbox.com/s/npzopi9xa2fwjxk/2...121533.jpg?dl=0