Breaking in Exedy Heavy Duty Stage 1

[rarenavr4]

Hi there,

After my OEM clutch gave in, I replaced it with an Exedy stage 1 240 mm. Problem is I'm experiencing excessive clutch chatter when going into 1st and (sometimes) 2nd gear. Thought that all it needed was a little bit of breaking in, but it's been 600++ km on the new clutch and that chatter doesn't seem to subside.

Anybody had experience on how many kilometers is needed to break in these heavy duty clutches? Or do I have another tranny problem - flywheel perhaps?

Thanks a bunch,

RAR

[Subaru ETA]

Was the flywheel machined?

[rarenavr4]

Was the flywheel machined?

No, it was not.

[Adam.Findlay]

No, it was not.

well there is your problem.
ALWAYS machine the flywheel when replacing the clutch.

[rarenavr4]

well there is your problem.
ALWAYS machine the flywheel when replacing the clutch.

And here I was thinking that you only machine the flywheel when it's warped. When the clutch was replaced, all I did was a little bit of emery cloth cleaning.

Well, I've got the transmission open and sent the flywheel to a machine shop. We'll see how it goes in a couple of days.

[Subaru ETA]

The flywheel probably had heat marks on it - especially if your old clutch was slipping. The flywheel isn't wrapped it just has too much run out

[Adam.Findlay]

even if its not warped the new clutch has to have a freshly machined surface to bed in propperly. hopefuly you haven't glazed your new clutch disc.

[swinks]

Good practice is to replace whole clutch kit including new flywheel. Anyway, prices for clutch kits including flywheel are not much more to those without flywheel. Myself always buying whole kit with flywheel.
As for juddering. It maybe flywheel issue, but not always. Some clutches, especially HD one or 4/6 puck require much longer bedding periods than usual. Recently I run 6-puck HD ACT clutch with lightweight flywheel and it taken 2000 miles to get proper bedding, which apparently is not unusual thing.

[Jnic0]

Yeah I've run mine in no chatter at all, even in break-in period. My mates workshop couldn't get it machined due to their lathe not being able to adapt to the shape. So, we just sanded it down and cleaned it. No problems.

[Adam.Findlay]

Yeah I've run mine in no chatter at all, even in break-in period. My mates workshop couldn't get it machined due to their lathe not being able to adapt to the shape. So, we just sanded it down and cleaned it. No problems.

facing flywheels in a lathe is less than ideal also. a proper flywheel surface is a ground surface.
you can sometimes get lucky and have a clutch not shudder on an unsurfaced flywheel but for the sake of $40 to get it done your stupid not to.

as for Swinks's comment that its good practice to replace the flywheel. not all kits come with flywheels. and its usually the price of the clutch if not more to get a decent new flywheel (well here in NZ at least) hence why refacing them is standard practice

[Jnic0]

facing flywheels in a lathe is less than ideal also. a proper flywheel surface is a ground surface.
you can sometimes get lucky and have a clutch not shudder on an unsurfaced flywheel but for the sake of $40 to get it done your stupid not to.

as for Swinks's comment that its good practice to replace the flywheel. not all kits come with flywheels. and its usually the price of the clutch if not more to get a decent new flywheel (well here in NZ at least) hence why refacing them is standard practice

Oh yeah, we tried on the lathe, but sanding it down was the next best option unfortunately. But did get all the heat marks etc off, it wasn't warped too. So not too bad.