New Cluch and Flyweel and Now New Shudder

[geoffbaltz]

Hello everyone. Hope you're all doing well.

I finally did the clutch and flywheel replacement. I went with the AASCO LWFW and the Spec Stage 1 Clutch with Spring Center.

I'm glad I did it since the old clutch was down to the rivots on the flywheel side. I also left the RMS alone as it was nice and clean in there and I'm a firm believer in the "if it works don't f%#* with it" theory.

The job itself was pretty easy as a clutch and flywheel job goes. I've done several on 944's and the 996 is a piece of cake.

I'm a bit concerned as I have a moderate shudder when starting in 1st gear and down shifting under load. I'm also getting a noticeable vibration/noise under 75% load in 1st and 2nd gear. I know it's not the noise from going to new flywheel as I was prepared for that (for all the people that ask if you can really hear the chatter when using a LWFW, yes, you can hear it). I think I may have bad motor mounts and now that the clutch hooks up stronger, the worn mounts are showing. I've been under the car and double checked everything and there is no evidence of missing anything on the clutch/flywheel job. I always torque everything to spec and mark every bolt on reassembly.

The mounts aren't leaking but I don't think that is always the case. I removed the driver's side mount and looked at it and it does have a date stamp of '99 on it so they are probably original. The car is a 2000 C2 w/74K miles on the clock.

Any thoughts or help?

[Loren]

Take off will be a bit more difficult with a LWFW. Less mass means you will need more revs and a little practice to get smooth starts - just like race cars.

[geoffbaltz]

Take off will be a bit more difficult with a LWFW. Less mass means you will need more revs and a little practice to get smooth starts - just like race cars.

Loren,

I totally agree and I do have some experience with this type of setup. Hopefully I'm paranoid but I think I may have a problem. Do the motor mounts always leak when bad? And how stiff are they supposed to be? Can you move the bolt around with your hands when removed?

[Orient Express]

You don't have a problem. A lighten flywheel also reduces the amount of dampening that the flywheel will provide at launch. The shutter is a free benefit of a flywheel with less mass.

[geoffbaltz]

OK, so maybe I am crazy. How about some answers to the motor mount questions.....

So I can sleep at night and prove that I'm crazy, I may just replace them anyway.

[Orient Express]

OK, so maybe I am crazy. How about some answers to the motor mount questions.....

So I can sleep at night and prove that I'm crazy, I may just replace them anyway.

If there is not any dark purple or green fluid dribbled down from where they are mounted, then they have not ruptured yet. That said, over time, certainly by 100K miles they will finally fail. New motor mounts can help isolate engine vibration, especially vibration at idle, but if the only thing that is different is the launch shudder, then replacing the mounts will not cure that. You got that for free when you reduced the rotational mass of the engine with the lightened flywheel.

[geoffbaltz]

Thanks for the info. I am fine with the shudder if it's normal. I only track the car so I don't have to live with it in traffic.

It just seems a bit excessive compared to other cars I've driven. One of which is a Cayman S Turbo (yes, a turbo from TPC) with the same flywheel and a different clutch. Engagement is smooth and there is no shudder.

[geoffbaltz]

Ok, I did notice something. I just put the rear of the car on ramps.

I then supported the motor to pull one of the mounts to look at it. I noticed that there is no play/travel in the motor when putting the jack under it.

I SWEAR that there was always a few inches of play before the motor started to lift the car.

[tac27]

Geoff,

Do you have a full lift, or did you only use jackstands while replacing the clutch?

I have an '03 996 Cab C2 that is nearly due for a new clutch; I'm debating whether to attempt the installation myself.

Tim.

[geoffbaltz]

Jackstands. You will need a transmission jack and you will need to get the rear of the car pretty high off the ground.

I put the front tires on ramps and then jack up the rear so the incline is minimal.

Edited March 18, 2009 by geoffbaltz

[maniac]

Hello everyone. Hope you're all doing well.

I finally did the clutch and flywheel replacement. I went with the AASCO LWFW and the Spec Stage 1 Clutch with Spring Center.

I'm glad I did it since the old clutch was down to the rivots on the flywheel side. I also left the RMS alone as it was nice and clean in there and I'm a firm believer in the "if it works don't f%#* with it" theory.

The job itself was pretty easy as a clutch and flywheel job goes. I've done several on 944's and the 996 is a piece of cake.

I'm a bit concerned as I have a moderate shudder when starting in 1st gear and down shifting under load. I'm also getting a noticeable vibration/noise under 75% load in 1st and 2nd gear. I know it's not the noise from going to new flywheel as I was prepared for that (for all the people that ask if you can really hear the chatter when using a LWFW, yes, you can hear it). I think I may have bad motor mounts and now that the clutch hooks up stronger, the worn mounts are showing. I've been under the car and double checked everything and there is no evidence of missing anything on the clutch/flywheel job. I always torque everything to spec and mark every bolt on reassembly.

The mounts aren't leaking but I don't think that is always the case. I removed the driver's side mount and looked at it and it does have a date stamp of '99 on it so they are probably original. The car is a 2000 C2 w/74K miles on the clock.

Any thoughts or help?

Hi geoffbaltz,

I'm very interest on installing the same setup that you have SPEC Stage 1 plus the AASCO LWFW on a '02 996 C2. What has been your experience after the installation?, Did your ride improved?, Still noisy?, How does it behave on the street?, Compared to OEM which one do you prefer?. Did you had to specify on your order the sprung clutch, or all of them come that way?, What is included in the clutch kit (throw out bearing, etc)?

[Benjamin Choi]

OK, so maybe I am crazy. How about some answers to the motor mount questions.....

So I can sleep at night and prove that I'm crazy, I may just replace them anyway.

If there is not any dark purple or green fluid dribbled down from where they are mounted, then they have not ruptured yet. That said, over time, certainly by 100K miles they will finally fail. New motor mounts can help isolate engine vibration, especially vibration at idle, but if the only thing that is different is the launch shudder, then replacing the mounts will not cure that. You got that for free when you reduced the rotational mass of the engine with the lightened flywheel.

per your advice, i just had my original mounts replaced with same factory ones. thx. kinda pricey. i think it was close to $300 for the two mounts + whatever labor i got charged at my indy.

[geoffbaltz]

maniac

I got the entire setup from Dave Lindsey at Lindsey Racing. You have to ask for the sprung clutch as you have to use the solid one with the standard flywheel.

I would never go to this setup for the street. There really isn't any reason to do it. The noise from the gear box sucks and the engagement with the clutch and the lwfw is not an easy thing to get used to and I would never want to drive around town with this setup.

For the track, I know I'll like it alot. I've had a chance to put about 200 miles on the car after the install on some nice roads. I definitely feel a difference in power and the motor does seem to spin up a bit quicker. I had a strange noise under heavy load in 1st and 2nd gear and a bit of a shudder initially but that has gone away. If you read earlier, I was almost freaking out about it. It was probably the clutch plate working into the new flywheel surface and I was getting used to the engagement. I should have listened to Orient Express and not worried about it. We have our first DE of the season this weekend so it's going to get a workout Saturday and Sunday.

-Geoff