Strange Grinding noise 69 GTO

[jtwoods4]

69 GTO.
A strange Noise is coming up through the transmission tunnel where my shifter mounts to the transmission. This started happening after I installed a new clutch and M22 Muncie.

We put the rear axles on jack stands and drove through the gears and the noise was not there. When the wheels are on the ground and the car is driving on the road noise comes back.

The noise does not happend all the time. It appears most in 3rd or 4th gear when running around 2000 to 2500 rpm. It is not there during steady driving at a constant rpm, but only during mild acceleration up around 2000 to 2500.

Here is the youtube video of the sound. You will definately know when you hear it. The video was shot at speed less than 40 mph.

http://www.youtube.com/watch?v=piEWJ9dyaG0&feature=youtu.be

[jtwoods4]

Well I did some research and other guys are reporting a similar sound with a metallic dual disc clutch, Mcleod RXT. Sounds like bolts rattleing in a coffee can in the 1800 to 2000 rpm range. Apparently its normal.

Pulled trans tongiht and the clutch, pilot bearing, and throw out bearing all look fine. Not strange wear marks on the input shaft.

[agto8u]

Maybe the front of the driveshaft/yoke is hitting the underside of the trans tunnel?

[andrewb70]

Well I did some research and other guys are reporting a similar sound with a metallic dual disc clutch, Mcleod RXT. Sounds like bolts rattleing in a coffee can in the 1800 to 2000 rpm range. Apparently its normal....

I can't understand why that noise would be considered "normal" no matter what clutch was being used. Have other guys explained why the McLeod clutch should make such a noise at a specific RPM? This does not make any sense from a mechanical/technical point of view.

Andrew