Clutch dragging at hi rev

[droppinbottom]

Just trying to figure out what others have done.

I am having a issue with shifting at hi rev.

This is a new tranny, new act 2600 6 puck, new master and slave, ss line from master to slave, and new clutch pedal assembly. I have the clutch adjusted for maximum engagement/disengagement.

The problem I am having is that at low rev's things seem to shift fine but at high revs it wants to grind the tranny on the 2-3 shift and the 3-4 shift. This problem became very evident this past weekend at the track so after 2 passes I decided not to try and abuse this tranny untill I can get it to shift better.

What have the rest of you done to resolve this? I am hearing that it is somewhat of a problem with the act clutches.

Thanks

 

[Drift_SM]

Bro, I've got the same problem.

New clutch, new T.O.B, new slave and master, stainless line, and its adjusted to have the most fluid travel possible.

I did the draging test in first gear. It fails around 6200 rpms mostly....somtimes it doesnt do it....and other times it does at different rpms between 62-7400 rpms.

I have a T.O.B noise...but idk how...its brand new!!!! Why is this thing dragging!

 

[TSiAWD666]

Was the flywheel stepped properly for the clutch you chose? Also I wonder if you're depressing your clutch too far... someone posted in a thread I read recently that the push-style clutch on our car wil actually begin to re-engage if you depress the fingers too far. If this is true then re-adjustment of your engagement via the pedal would be in order, assuming everything else is working.

 

[PieEyedPiper]

Was the flywheel stepped properly for the clutch you chose? Also I wonder if you're depressing your clutch too far... someone posted in a thread I read recently that the push-style clutch on our car wil actually begin to re-engage if you depress the fingers too far. If this is true then re-adjustment of your engagement via the pedal would be in order, assuming everything else is working.

Thats an interesting thought. Do you have a link?

 

[Ben]

I'm about to do some digging on the subject.

I got a fresh value build from jacks for my 91 awd plus a few add ons. Well within 400 miles it wouldn't shift into 3rd or 4th. Sent it back and they told me they could tell my clutch was dragging from the syncro wear. I just got the trans back in the car from the repairs Monday.

I had a findanza flywheel(with the incorrect step hieght) and a warped act pressure plate. I went back to a stock flywheel and brand new act street disk. I assumed this was my problem. nope. After Jacks machined my new clucth set up to a perfect matching set, my car is still creaping foward at about 6500, I bled the clutch again, then it would creap foward a little about 6800.

I have a brand new factory master(adjusted all the way out) and slave. my clutch pedal is not worn from what I can tell, I have a braided line. I also have an extended slave arm (I know, it's a bandaid, but I'm trying everything at this point)
My fork and ball looked ok, but that's just visual. The play in my pedal makes up about 1/2 an inch of pedal play.

I'm thinking next of just getting a new pedal assembly, new fork and new ball.

I'm beading it using a 1 person bleeder. I coke bottle with a piece of vac hose going from the bleeder on the slave to the coke bottle submerged in fluid.

I have to be missing something somwhere.



EDIT: I also have a new factory TOB that has a few thousand miles on it.

 

[Drift_SM]

Im using a fidanza flywheel also. When I talked to Jack...he told me I probably have a warped pressure plate. I don't know how a new fidanza flywheel could have INcorrect step hight. If I recall he told me that its only possible on flywheels that have been resurfaced and to much material was removed.

Its very true that the pressure plate fingers can be pushed to far resulting in a drag..but I have had this clutch adjusted to be right off the floor....and right up top...it still reacts the same.

The only part of the system that is extended is the fulcrum (pivot ball) was shimmed by jack himself. He said it is a must for running heady duty pressure plates. Even on a new flywheel.

I can't remember correctly if I put grease on the input shaft and spline. I know I packed the bearing and greased the plastic sleeve like a champ. Im hoping I have a failed T.O.B that is causing the dragging. It is making alot of noise. (Grinding, knocking at idle, but gone when depressed) it also squeaks when the car is off and I push the clutch in and out.

I think jack should chime in here....I'll shoot him a PM.

 

[Ben]

Transmission Videos

I forogt this was on his site. I'm doing some watching right now.

From what they told me, Fidanza just made them with too tight of a step hieght.
I measured mine and it was too small.

I'm about to watch the pivot ball shimmng video after I run outside and try to push my slave in by hand(talks about this in video for adjusting pedal)

EDIT: Well, I'm able to push the slave back in with my thumb and watch teh fluid level go up and down.
Also my clutch fork right where he says it should be in the hole. in the middle area, a little closer to the slave cyl.

I was hoping to find something.

 

[Drift_SM]

Ben, when you say the step hight was to tight you mean it was literally pushing into the disk instead of being to far away from it?..which is the common step hight issue. How do you measure it?

 

[Ben]

Ok, I'm going to call the outside ring on the flywheel that the pressure plate bolts to columns. cause they kinda look like columns standing up all around the flywheel. Well the columns are just a little too short so this brings the PP a little closer to the flywheel leaving a smaller distance between the friction surfaces on the flywheel and PP.
The step hieght is the distance from the top of the column to the friction surface.
There's a really good write up on it at RREs site.

I used a straight edge and a micrometer to measure the step hieght in many places to kinda get an average.


RRE's Clutch And Flywheel Tech Info

 

[Ben]

I think jack should chime in here....I'll shoot him a PM.

I hope he does. There's a few customers in here.

Somewhere I read something he wrote about pushing the clutch fingers too far and rubbing the PP. And having similar symptoms to to dragging clutch.

 

[Ben]

I bled the clutch hydrolic system using this method: How to Bleed a Hydraulic Clutch - Team Rip Engineering

That helped a little. Now my car doesn't move til right around 7k

 

[TSiAWD666]

Op, did you replace the shift fork and fulcrum ball when you replaced the tranny? If those are worn down you may not be getting enough disengagement of the clutch.

 

[PieEyedPiper]

I can't bring myself to test a 7k rev in neutral. Call me old fashioned.

 

[Ben]

I think I'm going to go ahead and order a new fork and pivot ball today.
Then shim the pivot ball next week when I put the new fork in.

 

[JackM]

Hello! The ACT dragging issues can be a complete nightmare and what helps and works for some may not help others.

Ben, got your email too, I know your clutch is set up right and is now perfect. If your TOB fork is in the middle of the opening of the trans then chances are the pivot ball and fork are right too. I would start to think that maybe there is a problem at the clutch pedal. If you push the pedal to the floor, let off, then grab the pedal with your hand and pull up does it move up any farther that it did by itself? If it does, then your clutch pedal assembly needs to be replaced. Let me know. If it feels okay, I have some other ideas.

A clutch puts synchros through hell when you shift at an RPM in which it will drag. If you find that it drags at 6.5k RPM, then that will have to be your redline until you can get it up higher if you want it to shift fast and smooth. You can still shift the car while the clutch is dragging, but you will wear out the synchros and it will feel like garbage. IOW, you will be slower. If you are able to get an ACT single disk unit to not drag at 7k or below, that may be all she wrote. Some are able to get them to go as high is 8k RPM, but most I see are around 7-7.5k. Yeah, I know, it really sucks.

If you want to go beyond 8k then the best thing might be to go with a twin disk I hate to say...

Here are a few other things to keep in mind:

With all of these clutches it is highly recommended to use the factory throw out bearing from Mitsubishi.

If you use a 4 or 6-puck disk DO NOT use the sprung units! The 4 or 6-puck units are too aggressive for the sprung hubs and the hubs break often at the rivets.

The more aggressive the disk and hub springs, and lighter the flywheel the more torsional whip/engine harmonics will resonate through the drive train. IOW, if you hear a womp-womp-womp noise through the driveshaft at moderate load while driving, it is the noise resonating through the shaft as there is no longer any mass at the flywheel or absorption at the disk to take it away. This is normal when modifying the clutch in an AWD car and just another noise to deal with.

When using a heavier clutch you absolutely have to adjust the clutch pedal assembly for more throw and be sure the clutch hydraulic system is in excellent condition. You will also need to perform this test to be sure you don't have a dragging clutch and damage your tranny:
Have the car running with the e-brake off so it can roll.
Push the clutch pedal all the way to the floor and hold it there.
Turn off your launch limiter in DSM link if equipped so the engine can hit 7K RPM.
Put the car into 1st gear.
Rev the engine up until you feel the car start to move forward. If the car moves forward below 7200RPM, your clutch is dragging.

The more aggressive the clutch, the shorter the life expectancy. On average, we see about 1 year (10k miles) of street and strip use out of a street disk ACT 2600 clutch.

When replacing clutch master or slave cylinders you absolutely have to use OEM factory units from Mits (the dealer). DO NOT buy OEM 'replacements' from ebay or the autoparts stores. They are junk and will ruin your tranny!

If a 1G DSM is having a heavier clutch assembly installed, the clutch pedal z-bar needs to be inspected for wear. One way to check is to pull up on the pedal. If it moves up by hand it is bad and needs to be replaced or the clutch will always drag and damage the tranny. DO NOT weld the pedal assembly! This doesn't work! Replace the parts with new ones from the dealer. Come on, give us a break, they are cheap and it's not worth having a shortened throw due to a hack-job welded clutch pedal assembly because spending $100 to do it right is too much. The headaches of not replacing the parts and having to do a tranny rebuild and re-do the clutch pedal assembly all over again will make you wish you didn't cheap out on that $100.

If any of you have tried all of this and still have issues let me know. I will try to help here as much as I can, but sometimes it is very difficult to know what can cause the issue without having the car in front of me.

Jack

 

[droppinbottom]

Wow, I kind of forgot about this thread untill I saw it one the front page. Guess that happens when the car has been sitting on stands for almost a month.

We are going to take the ACT crap out of my car in the next few weeks. I am going to switch over to the Quartermaster twin clutch.

Everything was done correctly on the clutch. All work was performed by Lucas of English Racing. Needless to say he is very disapointed with the way this car came out and has gone above and beyond to help me get things right. The only thing I don't think we did was step the flywheel as it was a brand new one but I will ask him this evening about that aspect.

We are using the 2600 6 puck with sprung hub. It is definitly dragging up top and has sometimes caused 4th gear lockout. I am reving to 8500 currently but am not able to shift easily at this rpm and have to wait for the rev's to drop before even attempting to get it in gear. Was sad to see slower times at the track with the amount of work that has gone into this car this season. Hopefully next season goes better.

Jack thanks alot for giving some advice unfortunatly I think you are right and will have to shell out the money for the twin disk clutch.

Also thanks very much for the videos you have made. They have helped me and alot of others imensly.

 

[Morphius]

Hello! The ACT dragging issues can be a complete nightmare and what helps and works for some may not help others.

Ben, got your email too, I know your clutch is set up right and is now perfect. If your TOB fork is in the middle of the opening of the trans then chances are the pivot ball and fork are right too. I would start to think that maybe there is a problem at the clutch pedal. If you push the pedal to the floor, let off, then grab the pedal with your hand and pull up does it move up any farther that it did by itself? If it does, then your clutch pedal assembly needs to be replaced. Let me know. If it feels okay, I have some other ideas.

A clutch puts synchros through hell when you shift at an RPM in which it will drag. If you find that it drags at 6.5k RPM, then that will have to be your redline until you can get it up higher if you want it to shift fast and smooth. You can still shift the car while the clutch is dragging, but you will wear out the synchros and it will feel like garbage. IOW, you will be slower. If you are able to get an ACT single disk unit to not drag at 7k or below, that may be all she wrote. Some are able to get them to go as high is 8k RPM, but most I see are around 7-7.5k. Yeah, I know, it really sucks.

If you want to go beyond 8k then the best thing might be to go with a twin disk I hate to say...

Here are a few other things to keep in mind:

With all of these clutches it is highly recommended to use the factory throw out bearing from Mitsubishi.

If you use a 4 or 6-puck disk DO NOT use the sprung units! The 4 or 6-puck units are too aggressive for the sprung hubs and the hubs break often at the rivets.

The more aggressive the disk and hub springs, and lighter the flywheel the more torsional whip/engine harmonics will resonate through the drive train. IOW, if you hear a womp-womp-womp noise through the driveshaft at moderate load while driving, it is the noise resonating through the shaft as there is no longer any mass at the flywheel or absorption at the disk to take it away. This is normal when modifying the clutch in an AWD car and just another noise to deal with.

When using a heavier clutch you absolutely have to adjust the clutch pedal assembly for more throw and be sure the clutch hydraulic system is in excellent condition. You will also need to perform this test to be sure you don’t have a dragging clutch and damage your tranny:
Have the car running with the e-brake off so it can roll.
Push the clutch pedal all the way to the floor and hold it there.
Turn off your launch limiter in DSM link if equipped so the engine can hit 7K RPM.
Put the car into 1st gear.
Rev the engine up until you feel the car start to move forward. If the car moves forward below 7200RPM, your clutch is dragging.

The more aggressive the clutch, the shorter the life expectancy. On average, we see about 1 year (10k miles) of street and strip use out of a street disk ACT 2600 clutch.

When replacing clutch master or slave cylinders you absolutely have to use OEM factory units from Mits (the dealer). DO NOT buy OEM ‘replacements’ from ebay or the autoparts stores. They are junk and will ruin your tranny!

If a 1G DSM is having a heavier clutch assembly installed, the clutch pedal z-bar needs to be inspected for wear. One way to check is to pull up on the pedal. If it moves up by hand it is bad and needs to be replaced or the clutch will always drag and damage the tranny. DO NOT weld the pedal assembly! This doesn’t work! Replace the parts with new ones from the dealer. Come on, give us a break, they are cheap and it’s not worth having a shortened throw due to a hack-job welded clutch pedal assembly because spending $100 to do it right is too much. The headaches of not replacing the parts and having to do a tranny rebuild and re-do the clutch pedal assembly all over again will make you wish you didn’t cheap out on that $100.

If any of you have tried all of this and still have issues let me know. I will try to help here as much as I can, but sometimes it is very difficult to know what can cause the issue without having the car in front of me.

Jack

The only thing I have to disagree with is welding the pedal. Sure, the best method is a buying a new one. Yet, there are hundreds of DSMers out there that have gone the welded pedal route and it has worked. There are wrong and right ways to weld it. Do it right, it'll last. I have 60K+ on a welded pedal/2600 setup.

 

[Ben]

The only thing I have to disagree with is welding the pedal. Sure, the best method is a buying a new one. Yet, there are hundreds of DSMers out there that have gone the welded pedal route and it has worked. There are wrong and right ways to weld it. Do it right, it'll last. I have 60K+ on a welded pedal/2600 setup.

I'm sure one reason the businesses that rebuild transnissions don't suggest welding the pedal is cause there's always going to be that person that will get their pedal welded, something will break, then they'll blame Jack. Now Jack's has to get their lawyer out and loose time and money fighting this crazy case, cause he said it was ok.



Now, at what point off the floor do all your clutch pedals engauge??

Mine is about 2-3 inches up. closer to 2 then 3 I think.

 

[Ben]

yyaaaaayyy.
I put in new factory TOB, TOB clip, clutch fork, ball, and got me a boot for the clutch fork.

Now it's worse. It's back to moving a little over 6500. Before It would start moving just under 7k.

 

[JackM]

Is your adjustment under the dash as far out as it can go before threading off of the bracket? Some 1G units can't go out far enough. Does yours have that problem? If it does there is an easy fix for that. Let me know.

Jack

 

[Ben]

Yeah, the master cyl rod under the dash is adjusted all the way to the end of the shaft. There's maybe 1/2 a thread to a full thread left.

 

[droppinbottom]

I know some people don't like this solution but the welded nut on the end gives you a little extra adjustment and if you don't need to thread it out that far then there is no damage done. I did not like the idea of only having a little bit of threading holding the rod in with as much pressure is seen there on those threads so I welded a nut on the end to help me sleep at night.

 

[Ben]

It's hard to wait patiently when you've been fighting a problem for weeks and there's something like this hanging out there.

there is an easy fix for that

haha

 

[Morphius]

New pedal assembly, if it's worn, welded wrong (ie one biased the lever wrong), or simply fatigued too much(ie cross shaft is now permenently torsionally deformed.)

or

3000gt VR4 slave. (last resort if nothing else gets you there)

 

[Ben]

Pedal isn't worn. there is almost no play at all in it.