Slipping clutch = shaking?

[eboy0]

Well i got my fuel supporting mods in place last weekend, and the car has some real balls now, I think dsmlink recorded 34lb/min @ 11 psi.... my question is. I took it on the highway to do some pulls and I know it's slipping, 3rd holds up barely, if I feather the gas, once I slam on it WOT, it just free-revs... so here's the situation, I slam on the gas and the car feels like it's riding on speed bumps, it never did this before and it only does it at WOT, does a slipping clutch feel like you're driving on speed bumps?

I'm getting absolutely no knock, I think timing is at 13* at WOT.

BTW clutch was installed by previous owner so i have no idea what it is exactly.

 

[pitbull419]

Usually a slipping clutch only lets the rpms rise while there is no equal change in speed.
What do you mean by speed bumps?The car shakes?Vibrates?Bucks?
How high are you rpms when it does what ever its doing?Does it do it as soon as you hit the gas or only once it reaches a certain rpm?
Do you have an oil pressure gauge?What is your oil pressure at idle and wot?
How does your car idle?

 

[eboy0]

Usually a slipping clutch only lets the rpms rise while there is no equal change in speed.
What do you mean by speed bumps?The car shakes?Vibrates?Bucks?
How high are you rpms when it does what ever its doing?Does it do it as soon as you hit the gas or only once it reaches a certain rpm?
Do you have an oil pressure gauge?What is your oil pressure at idle and wot?
How does your car idle?

Well, when I slam on the gas in any gear after 2nd, the RPM go from 3k to 7.5k almost instantly, while speed only goes up 2-5 mph more.
Maybe speed bumps was an exaggeration, more like vibrates... doesn't buck or misfire/knock or anything, just no power+vibration.
Idle oil pressure = 18 psi 'ish
WOT = 75psi +

It happens when I slam on it WOT, when i feather the gas it doesn't shake as badly.

Car idle perfectly, around 700+-50, my LTFT lo/mid are within reason and my injectors are setup for the current setup.

Could it be the pressure plate just giving out?

It's weird though, the clutch seems to engage about the same spot, fairly low, in a low gear.

 

[pitbull419]

Does it start shaking as soon as you go wot?Or when it gets to 7500rpm?

Just wondering.How many miles are on your car?

 

[eboy0]

Does it start shaking as soon as you go wot?Or when it gets to 7500rpm?

Just wondering.How many miles are on your car?

As soon as I slam on it.
I just turned over 81k last week or so.

Its weird it only does it in a high gear, I mean, when I do a full 1st-2nd gear pull i'm already going 70mph so speed doesn't seem to be a factor to why its doing this.

 

[pitbull419]

When your in 1st or 2nd does your clutch seem to slip????

 

[brthmltn]

Not that i'm going to be any help but I just posted about my clutch might be going out and its not to old and car is bone stock. Its been kind of cold here but not horrible and just out of the blue no clutch looks like the fork is all the way disengaged but not really any power. When it does move I did get a little vib around 5,000 but I let off. Kind of felt like the clutch was grabbing again almost. I think I'm going to replace and go bigger sorry to kind of high jack.

 

[kmoore]

When my clutch was slipping... I did notice a shaking in the clutch pedal... I don't know what caused it, but I did have some shaking.

 

[fertez_turbo]

The longer the gear the more prone the clutch will be to slip in, thats probably why you notice it more in 3rd gear than 1st/2nd. When it slips do you notice any kind of burning smell? You can almost always smell a clutch when they slip bad enough. My old Talon you could, anyways. Did the vibration ever occur before the clutch started slipping?

 

[el guapo]

If you wanna try to get a look at the pressure plate you could pull the boot of your throw out fork and try to look up there with a shop light or a flash light.At least that would tell you if it was still a stock clutch or not.You could see if there was a bunch of disk dust or anything thats not supposed to be there.The flywheel has probably gotten heat warped from excessive slipping and is causing the vibration.You should just tear it down and get a new clutch and get the flywheel resurfaced.

 

[eboy0]

I'm hoping it'll hold up for now, I wanna turn that into my spring project.... weird how it'd just get worn away so fast, I hardly burn clutch, though I do smell a weird odor after this "shaking" occurs...

 

[el guapo]

They just fall out of spec it happens clutches wear down.It doesnt take much to over power a stock clutch though.

 

[fertez_turbo]

They just fall out of spec it happens clutches wear down.It doesnt take much to over power a stock clutch though.

Exactly. BAck when my roommate was a near stock 99gst, he cranked the boost up a little on a T25 with exhaust and intake and his clutch was gone within a few months or so. Only had like 60k on the car.

 

[eboy0]

I am getting a slight "kicking" feeling in my brake pedal when pressed in....hmmm? It seems to be getting worse now, 2nd gear at top end seems to be giving me a slight shake, could this be motor mount related as well?

 

[fertez_turbo]

I am getting a slight "kicking" feeling in my brake pedal when pressed in....hmmm? It seems to be getting worse now, 2nd gear at top end seems to be giving me a slight shake, could this be motor mount related as well?

Yes if your car has 80k+ miles and stock motor mounts they would definitely need changing. Prothane's arent very expensive either and are a nice upgrade.

 

[iziegsx]

Currently i have the same problem with my clutch but my car is lightly moded. The car shakes when i go into a high gear. If u listen closely you may even hear a hitting sound at times from your clutch. There is a sale on clutch kits from Custom SSI. Take advantage of that its pretty good. If you continue to drive on a slipping clutch Im sure something must get damaged, don't know what but i think something will. Plus its a gamble, you could be 1000 miles away from home and your clutch says "I've had enough". Good luck man.

 

[DGajre777]

You need a new clutch. My clutch was replaced at 45,000 (previous owner) and then again at 63,000.

While you are replacing your clutch, change your rear lower motor mount (get a new one from Mitsubishi), or get prothane or energy suspension bushings (that are INSERTS).