Derf00

OP, why did you go with Poly motor and tranny mounts? those definitely add to NVH for no noticeable gain. If it were suspension then there's a trade off, better handling for a bit more NVH but for engine and tranny mounts, I don't see any advantage. All there is, is disadvantage.... Just asking.

Simon1

Most do it for header clearance, SC clearance, and also clutch engagement. In my experience it doesn't create anymore noise, but does increase vibration slightly. I'm sure there is some extra noise associated with it, but I cannot hear it.

The poly mounts prevent a lot of flexing and has helped some with clutches that do not engage properly at high torque loads. It helps very little and usually the only thing that fixes it permanently is a better clutch.

Choppertwo

Yeh, could be when they put the new clutch in, they didn't put a new flywheel in OR B didn't resurface the existing flywheel , good luck man

Choppertwo

Oh FYI, resufacing should only be @$50.00

Norm Peterson

OE rubber engine and transmission mounts can contribute to wheel hop.




Norm

ticopowell

I am not doubting you in any way, but I am wondering how that works? I guess I assumed that wheel hop was because of the rear axle bouncing around, not sure how having a more fixed part 8 feet away is going to help that...
I know the drive shaft connects them, but I guess I didn't think it transferred anything significant to the rear except it's own rotational movement.

Dino Dino Bambino

That's the first time I've ever heard that. What's the scientific explanation?

Norm Peterson

OE engine and transmission mounts are really just another set of compliant bushings that can store and release energy. In their case, this back and forth flow of energy acts directly on the driveshaft in a rotational sense. That means you have a more or less fixed amount of D/S torque corresponding to the engine's torque curve times transmission gear reduction . . . plus this vibratory component.


Therefore the torque getting to the tires is unsteady. Even if the suspension bushings are rigid, there is still this vibrating force at the contact patches trying to put the tires into a stick-slip situation.


I think it would be interesting if somebody took a series of underhood videos of a car with the OE powertrain mounts during wheel hop like the UCA video that's been around for a while.


Norm

Horylev1145

Original owner stated he had the flywheel resurfaced when he did the new clutch install but who knows. I appreciate the advice and I know now that I'm doing a new clutch, flywheel, slave cylinder and TOB but I'm curious if anyone has an idea as to what this noise is in the video below. May be related im not too sure. Iv never heard anything like this before. I took the rubber boot off the bottom of the shifter when I swapped the trans fluid and noticed this noise. Its most likely always been there just was not as noticeable with the shift boot rubber in place.

Sounds as if something is rattling toward the front of the transmission/clutch area. Noise is always present unless the car is in gear and given a fair amount of gas. If the car is left in gear (IE costing) but I don't give the car any gas I hear the noise. Noise is heard if the clutch is depressed or released. Like I said the noise only goes away when your giving the car 20%+ throttle while in gear.

You will hear the rattle pretty clearly toward the end of the video.

http://vid813.photobucket.com/albums...5-15-09-35.mp4

Simon1

I can't really tell what I'm listening too. My throw out bearing made noise for a few years before it finally went out.

If you are keeping the car for a long time, I would probably replace the throw out bearing/slave cylinder and the entire clutch assembly. Which is another small chunk of change...