Jerking/bucking upon clutch engagement.

[Pritchett]

So here's the deal, installed new klze, with a flywheel that had been freshly resurfaced and used for about 10km on old motor and a xtd stage 3 clutch(new minus 10km).

0-50km car made jerking motion only in reverse
50-270km jerking got a little worse
270-320km now in 1st it has same symtoms when starting off and it's worse again in reverse.

I talked to a mechanic at work who deals with tractor trailers and he said from my description it Sounds like it's slipping. However it pulls like a son of a gun and will peel out in 2nd and scuff the tires going into 3rd. Also it will spin them in 2nd if I rev it and dump the clutch while driving at like 3-4k rpms in 2nd. If I apply anything more then a very light throttle application during engagement in 1st the symptoms disappear.
It doesn't feel like it's slipping by the amount of acceleration I have and I'm pretty sure it would slip more under hard throttle then slowly engaging it at idle.

As always any insight or opinion is much appreciated and welcome, thanks guys!

[Ryan]

I am quite sure this is a TPS/IAC/Neutral/clutch switch issue.

If you're at low throttle (like all the scenarios you suggest) then the motor can't decide if it wants the idle air path or not... making the motor surge, making the car jerk (power, no power, power) and with the drivetrain lash....


What tires are you rolling on? I'm on BFG G-force's and I only chirp 2nd. I don't drop my clutch though, ever.

[Pritchett]

Tires?? Hmmm pretty sure they are toyo's...not sure about which model and I'm currently working near Pearson, mb...so I can't check

They look to be below the normal air pressure. I was quite impressed when I first scuffed them going into third. Seeing how the k8 wouldn't even scuff in 2nd, that could have been the clutch with 270,000km on it as well tho

[2fazed]

just like your clutch, i bought one of those f1 stage3 ebay clutches. right off the bat it jerked in 1st and reverse starting out. get yourself a better clutch.

[wytbishop]

A stage 3 clutch is designed to hold what...300hp? It's so sticky and the spring force is so high the it is trying to engage the instant it contacts the flywheel.

I think this is just the wrong clutch for the ZE.

[crazycanadian]

IS it only when you are trying to slip the clutch to take off? or possibly work the clutch slowly between shifting gears???

Is the xtd stage 3 a puck clutch at all?? Did the center hub have springs in it?

Its sounds like you have clutch chatter due to a clutch thats to aggressive for street use... When you get up there in high performance clutches they want to work more like an on/off switch rather then be able to slip...

[Pritchett]

385hp 380ft/lbs is the rating, which is overkill for just the ZE but I wasn't sure if I was gonna turbo when I got it and I wanted to make sure It wouldn't slip.
It is a 6 puck, sprung clutch, it is only when I start off and I don't feather between gears. I have no problem dumping the clutch during shifts. I shift like I did with my K8 and stock clutch and even tho it had 270,000+km the clutch had lots of life left in it.
Im not worried now...what your saying makes sense about the on/off effect. I guess that's what the clutch was designed to do.
Thanks for all your inputs and opinions guys, when I get back from Manitoba, I'll still check those sensors just incase

[Ryan]

Hey, if you're in MB, you're likely in Winnipeg, in which case we should meet up

[Pritchett]

Man I would love to meet up and check out your ride, however I'm not in Winnipeg. Im currently staying in redvers SK, working near Pierson MB. Some times I stay in waskada,mb. That's probably still pretty far away tho.

[crazycanadian]

385hp 380ft/lbs is the rating, which is overkill for just the ZE but I wasn't sure if I was gonna turbo when I got it and I wanted to make sure It wouldn't slip.
It is a 6 puck, sprung clutch, it is only when I start off and I don't feather between gears. I have no problem dumping the clutch during shifts. I shift like I did with my K8 and stock clutch and even tho it had 270,000+km the clutch had lots of life left in it.
Im not worried now...what your saying makes sense about the on/off effect. I guess that's what the clutch was designed to do.
Thanks for all your inputs and opinions guys, when I get back from Manitoba, I'll still check those sensors just incase

You are going to run into a big problem daily driving with clutch chatter and a sprung hub.... The clutch chatter is absolute hell for the sprung hub.... Over time (1 - 2 years) it'll beat the springs to death and they will pop out... When that happens they will get jammed in the pressure plate and leave you with no clutch...

Your best option is to learn how to drive the best you can using that clutch as an on off switch even when starting off, or replace the disc with a full face disc... You can still get some good high performance clutches that have full face discs...

[Pritchett]

Ya, I just give it more throttle during initial engagement. It works flawlessly for 1st gear starts, reverse is a different story, but I find letting the clutch out a little, then disengaging it again, followed by engaging it again...pretty much clears up the bucking in reverse as well.

The other side of the story is the car is strictly a pleasure vehicle now. I work 15 days then get 6 off. Ive only put 320km on the car since the cars been road legal.(0 before it was of course ) Which was halfway through July. Plus I have more kids the availible seats in the mx, so I mostly use my truck or my fiancé's van.

Thank you for your input

[Ryan]

I STILL think its a throttle thing. The ECM switches between idle and "oh, you actually want to go eh?"

I always have to either ride the clutch in reverse, or keep a decent amount of pedal on it, or it lurches. First is not as bad. And I have a regular joe Exedy.

Look up in the wiring diagrams which is the clutch switch on the ECM, and make sure you get the correct readings.

If you did an ATX swap, I can guarantee its not working. Its not so easy as plugging it in, the pins are incorrect in the connector beneath the ECM... or if you didn't do an ATX, it could just be broken.

[greenstorm]

I have the same problem. I installed a stage 3 clutch and it shudders like hell if you try to engage it slowly.

I checked all my mounts, etc. Everything's fine, the clutch is just a little too much for street use I think.

It's an F1 Stage 3.

[Pritchett]

I've never swapped trannies, it's a manual from birth.
Greens clutch acts the same way, and is very similar to my clutch. Your clutch does the same Ryan? Is it possible that all 3 of us have the same sensor malfunction, or prehaps its a case of the clutch grabbing too hard to fast?

[wytbishop]

I have to respectfully disagree with Ryan in this case. Although it may be possible for a throttle issue to cause these symptoms, when you describe "bumping" the clutch to get moving and then engaging it more smoothly once it starts to move shows clearly that yours is a mechanical problem.

Think about the design of a puck style clutch and why they would do that. By removing 30-40% of the surface area of the clutch disc and shaping it that way they are effectively concentrating the application force of the pressure plate on the pucks. Instant grip when launching at 3000rpm, not so great for daily driving.