Heavy "Shuttering" When Starting in 1st Gear

[eman11500]

Originally Posted by soundman98

if you thrash on the car like it owes you money, does it still shudder?

Will try it in the morning and report back

[humfrz]

I suggest you bleed the hydrolytic clutch system. Maybe there is air in the system that is causing the clutch to act up -

[radroach]

@eman11500 any FR-S over 100k miles, get your transmission mount replaced or get the whiteline insert, as part of a "positive shift kit". Also consider getting the "positive traction kit" to fix drivetrain slop.

Also have you replaced the clutch throw-out bearing for the newer part?

[eman11500]

Originally Posted by radroach

@eman11500 any FR-S over 100k miles, get your transmission mount replaced or get the whiteline insert, as part of a "positive shift kit". Also consider getting the "positive traction kit" to fix drivetrain slop.

Also have you replaced the clutch throw-out bearing for the newer part?

I'm going to order the whiteline insert and a perrin transmission mount.

As for a newer TOB, unfortunately I neglected to tell the mechanic to order an additional 17+ bearing for the kit when it was installed. This was before I really knew how much of a difference it would've made.

[eman11500]

Originally Posted by soundman98

if you thrash on the car like it owes you money, does it still shudder?

The damn thing is barely even doing it today now. I launched fine without shudder, but I will go for another drive tonight and try it again if the shuddering comes back.

[BigTuna]

Seems like you're bogging the engine. I usually try to keep revs between 2-3000 rpm when slipping the clutch. Only when I let it drop to 1200, like you showed, does it shudder/bog.

[RToyo86]

Originally Posted by eman11500

I'm going to order the whiteline insert and a perrin transmission mount.

As for a newer TOB, unfortunately I neglected to tell the mechanic to order an additional 17+ bearing for the kit when it was installed. This was before I really knew how much of a difference it would've made.

That combo will introduce a good amount of NVH.
I have the white line insert and that takes care of 95% of the slop with very little NVH introduced.

It's about a 15 min install if you use a jack on the trans to slide the insert in. Between that and the Mtec shift springs was probably the two best bang for buck mods I've done to the car.

[Ultramaroon]

Just popping in here. There is definitely something unsavory going on. Don't throw mods at it. This is either a sloppy driveline issue, or there's something wrong with the actual clutch.

I'm leaning hard toward clutch chatter. Stock clutch should easily slip to the point of overheating without chatter. I've taught a couple folks how to drive stick on my car. It doesn't take much to get it hot and still, zero chatter.

Try a quick bleed. Just one squeeze. If you don't immediately get crackly air bubbles, move on. I think something is wrong with the friction disc.

[soundman98]

Originally Posted by eman11500

The damn thing is barely even doing it today now. I launched fine without shudder, but I will go for another drive tonight and try it again if the shuddering comes back.

so you said you replaced the clutch pack, do you know if the flywheel was resurfaced or replaced?

i'm wondering if it's just like 'warped brake rotors' where some clutch material from the old clutch disc is transferred to the flywheel, and now it's resulting in unevenness in the surface of the flywheel

[Ultramaroon]

Originally Posted by soundman98

so you said you replaced the clutch pack, do you know if the flywheel was resurfaced or replaced?

i'm wondering if it's just like 'warped brake rotors' where some clutch material from the old clutch disc is transferred to the flywheel, and now it's resulting in unevenness in the surface of the flywheel

Maybe it was overheated really badly and it has taken until now to wear down. OP's saying it's barely doing it. Just give it a little time? Some intermittent quick hard slips to clean off the flywheel without getting it too hot? I've never tried to bed-in a clutch but that doesn't mean it can't be done.

Ooo... Slip the clutch hard but finish by disengaging and idling until it has had a chance to cool?

[soundman98]

Originally Posted by Ultramaroon

Maybe it was overheated really badly and it has taken until now to wear down. OP's saying it's barely doing it. Just give it a little time? Some intermittent quick hard slips to clean off the flywheel without getting it too hot? I've never tried to bed-in a clutch but that doesn't mean it can't be done.

Ooo... Slip the clutch hard but finish by disengaging and idling until it has had a chance to cool?

i dunno, because the flywheel has some decent mass to it(duh), but no active cooling properties. would likely need to sit there with the clutch disengaged for a long time...

[soundman98]

part of me wonders if the OP is too nice to his cars and this is a result of not enough of an 'italian tuneup'

sometimes, ya just gotta thrash it!

[Ultramaroon]

Originally Posted by soundman98

i dunno, because the flywheel has some decent mass to it(duh), but no active cooling properties. would likely need to sit there with the clutch disengaged for a long time...

Actually, as long as you brought it up...



CLUTCH: CLUTCH SYSTEM: DETAILS; 2013 MY FR-S [03/2012 - ]

[jeepmor]

Sounds exactly like my issue after my SC install. Mine was worse on hot days after driving 20 miles or so. I had the shift bushing and trans insert already. I had more than one thing done with my clutch install, but it came on after the whitleline trans insert.

I put three whiteline bushing kits in since. Subframe, read diff connection and diff mount bushings. I stll get it, but no where near as bad or often. I'd go for the rear diff connections bushings first, then subframe kit.

I can feel it's from the rear diff bit, the kit stiffens it, but the frequency is still the same when I get it, albeit much rarer now and it holds it to smaller deflections. I was told clutch chatter at the start too, that's not it.