turboglenn
15+ Year Contributor
- 6,375
- 111
- Nov 5, 2007
-
RIpley,
West_Virginia
Well, as everyone probably knows i've been going through a lot with the trans and clutch. Well after it was all said and done i just ended up with a surfaced flywheel, same old ACT PP (glaze knocked off by sandblasting) and a cheap-o parts store duralast friction disk
Anyway! When i put the trans in and installed the clutch slave the pivot point was way past center to where you would normally want to shim it.. I thought this was odd since the PP and FW were the same and i'd replaced the disk with a semi-new one before from RPS when the ACT one went out... and was trying to decide on what had changed, I knew a LOT of material taken from the FW from many surfacings or one real major one if it were far out ofspec (which it wasn't) could cause this as well as having the friction disc be thicker moving the fingers further from the TOB..
SO, after not being able to catch my machinist in time to see how much was taken from my flytwheel when he surfaced it i pulled the trans and found a lock washer for a 12mm bolt that was .060" thick (1.5mm) and installed that under the ball. (because i didn't want to chance putting the entire car toghether and having to pull it apart for the 5th time in 2 weeks)
So anyway, I get it all together, adjust the clutch to where i was 1/2 turn from the master's return valve being blocked and started driving the car lightly around... within a days time i pull out on the road and the clutch slips a little when i gave it some gas in 2nd gear, I immediately pulled over at the next stop (about 1/2 mile of no slippin babying the car) and checked the clutch, well the "break-in" only being 50 miles in so far has already taken the 1" of pedal play out of the top and there was no play left at all.. I had a short wrench in the door just in case i needed to adjust it, and good thing i did, I got it back to about an inch of pedal free play and went back to driving..
When i got home more playt had been removed and needed adjusted again (i was about 20 miles from home when i slipped and fixed it). NOw what's happening is the disc (which is to ACT's spec of .330 thick compressed and .340 untouched ) is starting to get broken in and there's probably a few thousandths wearing into the flywheel and PP as well as it starting to "compress" from pressure on it.. and the clutch arm is moving well back into what would have been just fine without shimming the pivot by the time it's fully broken in (i'm sure of this with the amount it's moved already)
I"ll update and i hope i didn't over shim (why i went rather thin to start with was that i had an idea something like this would happen, but never recal dealing with it before)
So, in short, if you put in a new clutch and have your FW surfaced and the clutch arm is not in the area the DSM community describes where is should be or you need to shim it i wouldn't worry too much unless the arm is hitting the trans case when when or before the pedal is to the floor (this being you test it as soon as you get the trans and slave cyl mounted up but before putting EVERYTHING back together) You should be able to feel that "point" of the clutch going past the spot where you feel it normally go "ffree", if all that's good, it's not hitting and you're getting ddisengagement you probably shuoldn't shim it unless it's a clutch that the vendor or other people like twicks69 or any wiseman says is a clutch that will normally require shimming (and the ACT2600 is NOT one that shoudl need shimmed as i've never had to shim one out of all the ACT's i've installed or have friends with them installed)
And being at only 75 miles of a 500 mile break in, i've already gotten back enough to know that i don't need the shim in there that i put in, but anything on the web will tell you "shim it" but nothing on the web says "If your clutch is new, when it breaks in, the arm will move back towards where it should be" and that's what i'm trying to let some people know.... if it's only moved over "center" by the normal amount it is at to the other side of center i would say shimming is not needed (but the arm hitting the case would be my deciding factor bsed on what this has taught me, and this is my 5th clutch in this car over 12+ years, but i never hear about or worried about shimming any of the others that were installed, i just always would adjust my clutch to where i like it, which for me is something that changes every couple of months and something that on my bike i taylor during every ride since it's at my finger tips)
This is something you can figure out as soon as you get the trans onto the engine and install the slave to the setup, I would advise that if the clutch will disengage wihtoutnthe arm coming intoi contact or near contact with the bell housing then just run it and it will get back to where it should be when it breaks in..mine was only about as far to the passenger from center as it usually was to the proper side on the old clutch that was in great shape till it was coated in oil.. I know if i hadn't shimmed mine it will get aback to where it was, and now i have to be carefull of adjustment because the shimmed ball can cause over travel and destroy the clutch in the future, buyt since i keep strict tabs on the entire car i won't let that happen, but for the average person who's mechanic shims a clutch that don't really need it this could be a bad reality
Anyway! When i put the trans in and installed the clutch slave the pivot point was way past center to where you would normally want to shim it.. I thought this was odd since the PP and FW were the same and i'd replaced the disk with a semi-new one before from RPS when the ACT one went out... and was trying to decide on what had changed, I knew a LOT of material taken from the FW from many surfacings or one real major one if it were far out ofspec (which it wasn't) could cause this as well as having the friction disc be thicker moving the fingers further from the TOB..
SO, after not being able to catch my machinist in time to see how much was taken from my flytwheel when he surfaced it i pulled the trans and found a lock washer for a 12mm bolt that was .060" thick (1.5mm) and installed that under the ball. (because i didn't want to chance putting the entire car toghether and having to pull it apart for the 5th time in 2 weeks)
So anyway, I get it all together, adjust the clutch to where i was 1/2 turn from the master's return valve being blocked and started driving the car lightly around... within a days time i pull out on the road and the clutch slips a little when i gave it some gas in 2nd gear, I immediately pulled over at the next stop (about 1/2 mile of no slippin babying the car) and checked the clutch, well the "break-in" only being 50 miles in so far has already taken the 1" of pedal play out of the top and there was no play left at all.. I had a short wrench in the door just in case i needed to adjust it, and good thing i did, I got it back to about an inch of pedal free play and went back to driving..
When i got home more playt had been removed and needed adjusted again (i was about 20 miles from home when i slipped and fixed it). NOw what's happening is the disc (which is to ACT's spec of .330 thick compressed and .340 untouched ) is starting to get broken in and there's probably a few thousandths wearing into the flywheel and PP as well as it starting to "compress" from pressure on it.. and the clutch arm is moving well back into what would have been just fine without shimming the pivot by the time it's fully broken in (i'm sure of this with the amount it's moved already)
I"ll update and i hope i didn't over shim (why i went rather thin to start with was that i had an idea something like this would happen, but never recal dealing with it before)
So, in short, if you put in a new clutch and have your FW surfaced and the clutch arm is not in the area the DSM community describes where is should be or you need to shim it i wouldn't worry too much unless the arm is hitting the trans case when when or before the pedal is to the floor (this being you test it as soon as you get the trans and slave cyl mounted up but before putting EVERYTHING back together) You should be able to feel that "point" of the clutch going past the spot where you feel it normally go "ffree", if all that's good, it's not hitting and you're getting ddisengagement you probably shuoldn't shim it unless it's a clutch that the vendor or other people like twicks69 or any wiseman says is a clutch that will normally require shimming (and the ACT2600 is NOT one that shoudl need shimmed as i've never had to shim one out of all the ACT's i've installed or have friends with them installed)
And being at only 75 miles of a 500 mile break in, i've already gotten back enough to know that i don't need the shim in there that i put in, but anything on the web will tell you "shim it" but nothing on the web says "If your clutch is new, when it breaks in, the arm will move back towards where it should be" and that's what i'm trying to let some people know.... if it's only moved over "center" by the normal amount it is at to the other side of center i would say shimming is not needed (but the arm hitting the case would be my deciding factor bsed on what this has taught me, and this is my 5th clutch in this car over 12+ years, but i never hear about or worried about shimming any of the others that were installed, i just always would adjust my clutch to where i like it, which for me is something that changes every couple of months and something that on my bike i taylor during every ride since it's at my finger tips)
This is something you can figure out as soon as you get the trans onto the engine and install the slave to the setup, I would advise that if the clutch will disengage wihtoutnthe arm coming intoi contact or near contact with the bell housing then just run it and it will get back to where it should be when it breaks in..mine was only about as far to the passenger from center as it usually was to the proper side on the old clutch that was in great shape till it was coated in oil.. I know if i hadn't shimmed mine it will get aback to where it was, and now i have to be carefull of adjustment because the shimmed ball can cause over travel and destroy the clutch in the future, buyt since i keep strict tabs on the entire car i won't let that happen, but for the average person who's mechanic shims a clutch that don't really need it this could be a bad reality