LT1 T56 Clutch Problems
LT1 T56 Clutch Problems Trying to get a handle on what can be wrong with my clutch/hydraulics. I have 5K miles on my t56 swap with EVERYTHING being new, hydraulics, clutch, t bolt, fork etc and the clutch is officially smoked. From day 1 anytime I was backing out of the driveway or moving it into the garage where you never get to fully engage the clutch, it would make a wurring sound (I have a video I will upload later) and then will smell clutch. Ram told me thats just the clutch breaking in so I didn't think much of it, but it has never stopped. Also when driving the car hard in between shifts I smell clutch. The clutch does not engage (if its even fully engaging) until the pedal is almost fully out. It’s about 1 mm left on the throw before it actually engages. Any ideas of what I can check before I pull the trans.
I think 1 of 3 things can be happening:
1. For some reason the clutch is not fully engaging (the LT1 clutches are pull style) so therefore when its "engaged" the pressure of the PP forces the tob closer to engine, that moves the fork that pushes the piston of the slave cylinder in (toward the back of the motor).
2. The fork is not lined up on the TOB and when the clutch is pushed in its only grabbing some of the PP fingers.
3. The bolts of the PP are not torque properly allowing the pressure on the clutch disk to be more in places than others. VERY unlikely. I am OCD about torque things properly and making sure things are tight.
Other than that sound and the fact that my clutch is done after 5k miles there are no other noises. Also, other than that problem there are no other drivability problems. The stick moves easily when going between gears meaning its fully disengaging.
I wonder if its not fully engaging since my car engages so far out on the clutch throw, maybe the clutch is riding between the engage point and disengage?
I think 1 of 3 things can be happening:
1. For some reason the clutch is not fully engaging (the LT1 clutches are pull style) so therefore when its "engaged" the pressure of the PP forces the tob closer to engine, that moves the fork that pushes the piston of the slave cylinder in (toward the back of the motor).
2. The fork is not lined up on the TOB and when the clutch is pushed in its only grabbing some of the PP fingers.
3. The bolts of the PP are not torque properly allowing the pressure on the clutch disk to be more in places than others. VERY unlikely. I am OCD about torque things properly and making sure things are tight.
Other than that sound and the fact that my clutch is done after 5k miles there are no other noises. Also, other than that problem there are no other drivability problems. The stick moves easily when going between gears meaning its fully disengaging.
I wonder if its not fully engaging since my car engages so far out on the clutch throw, maybe the clutch is riding between the engage point and disengage?
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what TQ is PP bolts?
is the plastic cup still on slave piston?
is your fork bent at all?
do you have the slave spacer installed?
does the fork position look like the pic attached?
FYI if the TO bearing is installed right (really hard not to be) it engages all PP fingers evenly.
I don't think you can even install the disc backwards on a LT1 but the raised part (with springs) goes towards FW
LT1 pull clutches do have a tendency to engage high
slipping the clutch while starting up a hill, etc will cause it to burn some which is normal but you should adjust your engagement technique so "slipping" the clutch is not needed. Yeah sometimes you need to "feather" it some creeping up hills, on-ramps in traffic type of thing but keep the RPM's low.
your clutch sounds fried but if it is still in the car drive about 35 mph in 4th up a hill....stomp/floor it....does it slip?
it shouldn't unless you make enough power to over power the clutch.
is the plastic cup still on slave piston?
is your fork bent at all?
do you have the slave spacer installed?
does the fork position look like the pic attached?
FYI if the TO bearing is installed right (really hard not to be) it engages all PP fingers evenly.
I don't think you can even install the disc backwards on a LT1 but the raised part (with springs) goes towards FW
LT1 pull clutches do have a tendency to engage high
slipping the clutch while starting up a hill, etc will cause it to burn some which is normal but you should adjust your engagement technique so "slipping" the clutch is not needed. Yeah sometimes you need to "feather" it some creeping up hills, on-ramps in traffic type of thing but keep the RPM's low.
your clutch sounds fried but if it is still in the car drive about 35 mph in 4th up a hill....stomp/floor it....does it slip?
it shouldn't unless you make enough power to over power the clutch.
what TQ is PP bolts?
I checked the factory specs 25 ft lbs or something?
is the plastic cup still on slave piston?
No, i dont think its needed. I took it off thinking it was just for shipping purposes.
is your fork bent at all?
Nope
do you have the slave spacer installed?
The factory one is the only spacer I can think of, yes
does the fork position look like the pic attached?
no, its about 1/2" past the bell
FYI if the TO bearing is installed right (really hard not to be) it engages all PP fingers evenly.
It was installed on the clutch kit i bought
I don't think you can even install the disc backwards on a LT1 but the raised part (with springs) goes towards FW
Im POSITIVE i installed the hub part toward the flyhweel.
LT1 pull clutches do have a tendency to engage high
slipping the clutch while starting up a hill, etc will cause it to burn some which is normal but you should adjust your engagement technique so "slipping" the clutch is not needed. Yeah sometimes you need to "feather" it some creeping up hills, on-ramps in traffic type of thing but keep the RPM's low.
Yeah, i am not a new stick driver. I own 3 cars all sticks and have been driving them daily for 12 years. In fact my old daily driver got a new clutch at 150K.
your clutch sounds fried but if it is still in the car drive about 35 mph in 4th up a hill....stomp/floor it....does it slip?
In 4th no it wont, 5th and 6th, it slips really bad. it can maintain highway speeds but if I give it any more gas past that it slips.
it shouldn't unless you make enough power to over power the clutch.
I checked the factory specs 25 ft lbs or something?
is the plastic cup still on slave piston?
No, i dont think its needed. I took it off thinking it was just for shipping purposes.
is your fork bent at all?
Nope
do you have the slave spacer installed?
The factory one is the only spacer I can think of, yes
does the fork position look like the pic attached?
no, its about 1/2" past the bell
FYI if the TO bearing is installed right (really hard not to be) it engages all PP fingers evenly.
It was installed on the clutch kit i bought
I don't think you can even install the disc backwards on a LT1 but the raised part (with springs) goes towards FW
Im POSITIVE i installed the hub part toward the flyhweel.
LT1 pull clutches do have a tendency to engage high
slipping the clutch while starting up a hill, etc will cause it to burn some which is normal but you should adjust your engagement technique so "slipping" the clutch is not needed. Yeah sometimes you need to "feather" it some creeping up hills, on-ramps in traffic type of thing but keep the RPM's low.
Yeah, i am not a new stick driver. I own 3 cars all sticks and have been driving them daily for 12 years. In fact my old daily driver got a new clutch at 150K.
your clutch sounds fried but if it is still in the car drive about 35 mph in 4th up a hill....stomp/floor it....does it slip?
In 4th no it wont, 5th and 6th, it slips really bad. it can maintain highway speeds but if I give it any more gas past that it slips.
it shouldn't unless you make enough power to over power the clutch.
TECH Veteran
Joined: Apr 2008
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you need the plastic cup on slave piston. On a new slave it is compressed and straps attach to the cup. The straps break the 1st time you push in clutch after install leaving the cup on
with that said I would expect the opposite of your problem and you would have disengagement issues. Any way you don't want metal to metal contact between slave and fork so put the cup back on
PP TQ is 22 ft lbs but 25 should not be a problem and if PP bolts are to tight "disengagement" is the problem which doesn't sound like your deal
your spacer looks right. I never measured mine so don't know if someone cut yours down in a attempt to resolve (wrong) a clutch disengagement problem before but it looks normal unless you do see a sign it has been cut down which would bring the slave closer and keep pressure on PP
your clutch is toast if slips in 5th & 6th
Hard to tell by the pics but it looks like either your fork clip did not engage over the "T" stud or engage the TO bearing right so slave is holding to much pressure on fork not allowing clutch to fully engage. The end of the fork should not stick above the bellhousing that much. It should be pretty much flush with it.
When you put in a new clutch and stab the tranny slide the fork over TO bearing making sure clip goes over T stud with tranny about 1/4"-1/2" away from bellhousing then push tranny in the rest of the way. Never draw tranny in by pulling in with tranny bolts if it fights you pushing it in. In that case your disc is not aligned right and the input shaft pushes against the edge of pilot bearing and will F that up if you pull it in with bolts. You need to pull tranny and re-align disc again. PIA but it happens
with that said I would expect the opposite of your problem and you would have disengagement issues. Any way you don't want metal to metal contact between slave and fork so put the cup back on
PP TQ is 22 ft lbs but 25 should not be a problem and if PP bolts are to tight "disengagement" is the problem which doesn't sound like your deal
your spacer looks right. I never measured mine so don't know if someone cut yours down in a attempt to resolve (wrong) a clutch disengagement problem before but it looks normal unless you do see a sign it has been cut down which would bring the slave closer and keep pressure on PP
your clutch is toast if slips in 5th & 6th
Hard to tell by the pics but it looks like either your fork clip did not engage over the "T" stud or engage the TO bearing right so slave is holding to much pressure on fork not allowing clutch to fully engage. The end of the fork should not stick above the bellhousing that much. It should be pretty much flush with it.
When you put in a new clutch and stab the tranny slide the fork over TO bearing making sure clip goes over T stud with tranny about 1/4"-1/2" away from bellhousing then push tranny in the rest of the way. Never draw tranny in by pulling in with tranny bolts if it fights you pushing it in. In that case your disc is not aligned right and the input shaft pushes against the edge of pilot bearing and will F that up if you pull it in with bolts. You need to pull tranny and re-align disc again. PIA but it happens
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TECH Veteran
Joined: Apr 2008
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also I see your slave disconnected...you will need to bleed the hydraulics which can be difficult with the sealed system. Not sure why you disconnected it as you can just leave it hang once you remove it from tranny
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Verdad Gallardo Spacer is fine, not cut, i confirmed that.
Im positive the for is on the tob and is under the clip. I honestly dont see how people have problems getting the fork on the TOB. It looks to be impossible not to get it on right. the fork is tapered, line it up with the TOB and push till the clip snaps. Thats how i did it about 10 times.
I think the fork may be too far out because of something (clutch/flywheel/pp) is out of spec.
Also, disconnected slave??? my slave has never been disconnected, just removed from the bellhousing. where are you seeing that?
Thanks for the help
Im positive the for is on the tob and is under the clip. I honestly dont see how people have problems getting the fork on the TOB. It looks to be impossible not to get it on right. the fork is tapered, line it up with the TOB and push till the clip snaps. Thats how i did it about 10 times.
I think the fork may be too far out because of something (clutch/flywheel/pp) is out of spec.
Also, disconnected slave??? my slave has never been disconnected, just removed from the bellhousing. where are you seeing that?
Thanks for the help
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Joined: Apr 2008
Posts: 4,985
Likes: 112
Yeah putting on fork is pretty straight forward. Just, from this side of the internet, trying to ask ?'s and make observations on the pics (some kind of blurry) to help
the slave, at least that what it looks like in the last pic, is on the floor just to right of tranny...unless it is something else. Pic is slightly blurry so it looks like a slave which is why I asked.
In any event I would get the cup back on the slave piston. I can see in the pic where the cup on fork looks "shinny" from metal to metal contact. I don't think that is causing your complete engagement problem
something is making that fork stick out further. You got a new "T" so it should be right. I say that as on Twin disc clutch sometimes you need to cut the T stud down to raise the end of the fork because the Twin needs more slave travel and you need to raise the fork towards tranny or it will buzz the PP fully depressed. I now have a McLeod Street Twin and had to cut mine down. Anyway you have a single disc and stock length T so that should be right.
Your TO bearing where fork rests looks "redish" in color in the pics. don't know why but just an observation
looks like you need to get your FW resurfaced, new clutch and see if the fork sits differently.
I assume you don't have a oil leak that puked your clutch, right?
1st pic looks like oil/dirt inside bellhousing. I don't know if you cleaned that before install 5k mi ago.
FWIW I did a A4 to T56 swap too but on a B-body so know there are issues to iron out. But a F-body would be a little more straight forward as it was available as a stick and B-body weren't.
the slave, at least that what it looks like in the last pic, is on the floor just to right of tranny...unless it is something else. Pic is slightly blurry so it looks like a slave which is why I asked.
In any event I would get the cup back on the slave piston. I can see in the pic where the cup on fork looks "shinny" from metal to metal contact. I don't think that is causing your complete engagement problem
something is making that fork stick out further. You got a new "T" so it should be right. I say that as on Twin disc clutch sometimes you need to cut the T stud down to raise the end of the fork because the Twin needs more slave travel and you need to raise the fork towards tranny or it will buzz the PP fully depressed. I now have a McLeod Street Twin and had to cut mine down. Anyway you have a single disc and stock length T so that should be right.
Your TO bearing where fork rests looks "redish" in color in the pics. don't know why but just an observation
looks like you need to get your FW resurfaced, new clutch and see if the fork sits differently.
I assume you don't have a oil leak that puked your clutch, right?
1st pic looks like oil/dirt inside bellhousing. I don't know if you cleaned that before install 5k mi ago.
FWIW I did a A4 to T56 swap too but on a B-body so know there are issues to iron out. But a F-body would be a little more straight forward as it was available as a stick and B-body weren't.
Yeah putting on fork is pretty straight forward. Just, from this side of the internet, trying to ask ?'s and make observations on the pics (some kind of blurry) to help
the slave, at least that what it looks like in the last pic, is on the floor just to right of tranny...unless it is something else. Pic is slightly blurry so it looks like a slave which is why I asked.
In any event I would get the cup back on the slave piston. I can see in the pic where the cup on fork looks "shinny" from metal to metal contact. I don't think that is causing your complete engagement problem
something is making that fork stick out further. You got a new "T" so it should be right. I say that as on Twin disc clutch sometimes you need to cut the T stud down to raise the end of the fork because the Twin needs more slave travel and you need to raise the fork towards tranny or it will buzz the PP fully depressed. I now have a McLeod Street Twin and had to cut mine down. Anyway you have a single disc and stock length T so that should be right.
Your TO bearing where fork rests looks "redish" in color in the pics. don't know why but just an observation
looks like you need to get your FW resurfaced, new clutch and see if the fork sits differently.
I assume you don't have a oil leak that puked your clutch, right?
1st pic looks like oil/dirt inside bellhousing. I don't know if you cleaned that before install 5k mi ago.
FWIW I did a A4 to T56 swap too but on a B-body so know there are issues to iron out. But a F-body would be a little more straight forward as it was available as a stick and B-body weren't.
the slave, at least that what it looks like in the last pic, is on the floor just to right of tranny...unless it is something else. Pic is slightly blurry so it looks like a slave which is why I asked.
In any event I would get the cup back on the slave piston. I can see in the pic where the cup on fork looks "shinny" from metal to metal contact. I don't think that is causing your complete engagement problem
something is making that fork stick out further. You got a new "T" so it should be right. I say that as on Twin disc clutch sometimes you need to cut the T stud down to raise the end of the fork because the Twin needs more slave travel and you need to raise the fork towards tranny or it will buzz the PP fully depressed. I now have a McLeod Street Twin and had to cut mine down. Anyway you have a single disc and stock length T so that should be right.
Your TO bearing where fork rests looks "redish" in color in the pics. don't know why but just an observation
looks like you need to get your FW resurfaced, new clutch and see if the fork sits differently.
I assume you don't have a oil leak that puked your clutch, right?
1st pic looks like oil/dirt inside bellhousing. I don't know if you cleaned that before install 5k mi ago.
FWIW I did a A4 to T56 swap too but on a B-body so know there are issues to iron out. But a F-body would be a little more straight forward as it was available as a stick and B-body weren't.
That redish you see on the TOB is just the bearing grease I put on.
I do have an oil leak, its somewhere from the oil filter area, but no it has not gotten on the clutch the clutch is dirty/dusty, but not wet.
I have actually be trying to decide if I should pull the motor and trans at once to fix some oil leaks and a few other things over the winter, in addition to putting a new clutch in.