Stock SVT clutch shudder

[Lanky R]

Hello

I drive a 98 SVT with 42,XXX miles and I started to notice this problem at about 35,XXX miles. When I let off the gas or apply the gas abruptly the car lurches back and forth a lot. Now I know that all manual trasmissions do this when you mash the gas very quickly or let off from full throttle very quickly. But this happens much more easily, so easy that i have to TRY so the car wont do it. Even in cruise control in 4th gear the car will lurch on slight acceleration. Now I've had multiple other manual contours including 96 zetec, 98 duratec, and 2000 svt and none of the other cars drive like this at all. The 2000 SVT feels like a completely different car. It also takes the 98SVT a little more time for the clutch to grab when starting off, it doesnt grab like the 2000 SVT or even like the 98 SE did, and if i do let the clutch out quickly (not dropping the clutch, Ive never driven the car hard) it grabs a little faster but has a "chruchy" sort of feel. I have done multiple little tests to see if my clutch is slipping and It never seem to be, I can go full throttle in 5th gear at 25mph and revs go up slowly with the speed. My question is.. Is the clutch or flywheel bad? or is some other issue?
Thank you guys in advance!
-Ricky

 

[Silver Bullet]

I would check both front and rear roll resistors. When they go bad the sloppy engine/trans movement makes the car very jerky both accelerating and braking.

 

[Lanky R]

Thank you for your help! Are the roll resistors like motor mounts? all the pics i see on the forum look like motor mounts.
Is there anything I should look for like cracks when i check them? or should i just have them replaced?

 

[Tony2005]

Thank you for your help! Are the roll resistors like motor mounts? all the pics i see on the forum look like motor mounts.
Is there anything I should look for like cracks when i check them? or should i just have them replaced?

Yes, they are front and rear motor mounts. Sometimes, they crack and get "squished up".

 

[Lanky R]

I just took a look at the motor mounts and here is a pic of the one under the car. It seems to be "squished" and there are some cracks as well. Let me know if you think it needs to be replaced.

 

[Tony2005]

Can't tell from the picture, but if you think it is "squished", then go ahead and change it.

 

[Silver Bullet]

I just took a look at the motor mounts and here is a pic of the one under the car. It seems to be "squished" and there are some cracks as well. Let me know if you think it needs to be replaced.

Photo shows it's well worn, if there are cracks definitely replace it. Not a cheap part though, about $85. You will feel an improvement from this but for me mostly from smoother braking. Check your front one also, front will impact acceleration more. It is not so easy to inspect though, tucked in there very well. A small mirror and a flashlight help.

 

[Lanky R]

I'll see if i can take a look at the front one as well. Yeah $85 is a lot but im more worried about the labor of having a shop fix it. I read on how to do it myself but it seems a little to complicated for me to try it on my own.

When I first noticed the issue I was thinking of problems and one thing i came up with was that maybe there is (or was) a leak in the master clutch cylinder and because of this the clutch and flywheel were not being pushed together with enough pressure for "normal" engagement thus causing the weird lurchy-ness. Does that make any sense at all?... again I don't really know a lot about this kind of thing and you if guys think its the roll resisters ill have a shop take a look at them. Thank you guys for all your help!!

 

[dnbaholic]

When I first noticed the issue I was thinking of problems and one thing i came up with was that maybe there is (or was) a leak in the master clutch cylinder and because of this the clutch and flywheel were not being pushed together with enough pressure for "normal" engagement thus causing the weird lurchy-ness.

FYI, the pressure plate is what apples the clutch disk to the flywheel/pressure plate, therefor the master clutch cylinder has nothing to do with applying the clutch, it only releases it (clutch is always engaged unless clutch pedal is depressed). Hope that makes sense haha.

Good luck.

 

[Silver Bullet]

I'll see if i can take a look at the front one as well. Yeah $85 is a lot but im more worried about the labor of having a shop fix it. I read on how to do it myself but it seems a little to complicated for me to try it on my own.

Lanky R,

The rear one is very easy to replace, you can do it yourself even if you have never turned a wrench before. The front one though is a little more involved to replace. Front one typically doesn't go bad as fast and a little cheaper also ~$50

This is probably not all of your current problem but needs to be replaced soon anyway. Normal wear out maintenance item. Same as bushings, brakes, tires, struts, etc. As these cars age and get up in miles you need to keep up with the small things. Doing so will give you a very tight, smooth and noise free ride for a long time to come. Mine at 143K miles is still the tightest handling fwd car I have ever drove.

 

[Big Jim]

All of the above is good advise. The main thing is that what you are feeling isn't really a clutch problem. Clutch chatter is a vibration during engagement. It is not the roughness you describe one the clutch is hooked up.

That the alignment of the powertrain may be sloppy due to worn mounts/restraints is very likely. Perhaps the most likely.

You may also have a tune related problem. I had a light surge at about 35 mph in 4th or 5th gear at light or no throttle on hot days with the AC running. It was from the programming of the IAC. The IAC was fighting against a closed throttle. This can be somewhat minimized by getting up to date on tune maintenance (plug condition, injector cleaning, air filter condition, etc) and then cleaning the throttle body and IAC. For me that took care of about 60% of the problem. Adding the throttle hang fix cleaned it up to 80% to 90%.