Low speed drivetrain shudder

[adampecush]

I'm not sure if I should call this a problem, more of an annoyance I suppose. Anytime I'm moving the car at low speed, be it first or reverse, I encounter a rather severe drivetrain shudder, which sounds like it is focused around the differential. Since the drivetrain really only has ~750 kilometers on it, I'm wondering if this is a result of normal break-in, or if something is wrong.

When I say 750km on the drivetrain, I mean new clutch (spec 3+), machined/balanced flywheel, rebuilt transmission, rebuilt differential, and new OEM driveshaft centre bearing. Driveshaft is also in phase.

Anybody experience similar issues? A quick search on google revealed several GT500 owners experiencing this issue off the showroom floor.

 

[cjsupra90]

Do you notice it more-so while turning? If so then I'd suspect the diff being real tight and not allowing much slippage. It should go away pretty quickly unless it was built way to tight.

If you notice it while going straight, then I doubt it would be the diff unless the bearings are preloaded incorrectly.

I wouldn't suspect a DS problem as they typically are more noticable at higher speeds rather then lower speeds.

 

[adampecush]

It generally occurs when feathering the clutch, such as pulling the car into and out of the garage. I'm thinking it is just the clutch chattering, which in turn induces some rotational shocking into the differential. Only time will tell if it goes away I suppose.

 

[IJ.]

Does that clutch disc have Marcel wave springs between each friction surface Adam?

 

[boostaddict]

ya i know on my cousins mustang we just put a new tranny and clutch in. the same thing happened almost like flywheel chatter? it just so happened it went away after the clutch broke in.

 

[Poodles]

Stage 3 I believe is a puck clutch, so no marcel springs. As the clutch breaks in it gets better, or it could be an issue with the diff (what was replaced in the diff?)

 

[Bri7man]

I have the exact same prob as you, stage 3 f1 light fly. Engine's apart but have new carrier bearing to install once its back in.

 

[IJ.]

No marcels will do exactly what's being described, it's more noticable in reverse.

 

[adampecush]

3+ is a full faced sprung disk...don't know if the friction surfaces are separated by marcel springs though...

 

[IJ.]

Marcels are very different to Hub springs Adam.

I had an ACT that was full face sprung hub but no Marcels.

 

[adampecush]

yeah, I just realized that...I don't recall the friction surfaces being separated by anything other than a solid plate, so chances are there are no marcel springs.

Would have been great if I'd taken a picture of the disk before installing!

 

[IJ.]

Had a look at Spec's site and it's "404 Marcels not found"

It'll be a bit shuddery but "should" get better as it beds in then it should really only be noticable in reverse as I mentioned.

Removing shudder on take up is the marcel's only purpose in life but they're a weak point so are the first thing to go in a performace clutch.

 

[adampecush]

It certainly is most noticeable in reverse. Thanks for the input, it is good to know there is nothing out of the ordinary.

 

[Poodles]

I find it helps if you rev higher and slip the clutch more...