So I'm getting a rattling noise starting at about 4000 RPMs and continuing on upwards. Sound like it's under the car, right in the trans area, not underhood. ...and it doesn't sound like a big part. Certainly can't feel it through the pedals or the ole butt sensor. While under throttle, obviously the TB isn't engaged....it's just kinda hanging out on the clutch fork. Is there any chance it's just slightly contacting the input shaft and causing a mild rattling noise? I got under there and there definitely is a small amount of play, but it's not really loose per se. Still.....at high RPMs, lots of vibrations, heat etc. etc., I could certainly see it as being possible.

Any thoughts?

 

Is the TOB not riding over the front bearing retainer on the trans? Or are you running some kind of hydraulic TOB? I would think the TOB would never come anywhere close to the input shaft. Maybe tickling the pressure plate? But then you'd think it'd make the same noise anytime the clutch is in. Could try pushing in the clutch a little when it's making noise to see if the noise goes away when there's some pressure on the TOB...

Could be some kind of harmonic vibration. Sometimes it helps to have someone else ride in the car with you, for the extra pair of ears, and also so they can press on various parts inside the car to figure out things that are making noise. My favorites to date include the roof structure in my Mustang that wasn't ever welded on the passenger's side of the body, and didn't have any foam on that side of the roof skin either, and of course the ever popular vibrating E-brake lever button. The Mustang also has one of the seat belts that buzzes at certain RPMs.

 

haha....yeah...it's over the retainer. In my head I just pictured it spinning, but duh, that wouldn't be happening.

 

Usually, a TOB noise changes when the pedal is depressed or released.

If you want to know if it is the TOB: will it do it in any gear, while parked? If yes, lash or otherwise hold the outside end of the fork fwd. and see if the TOB is spinning. Shouldn't be. Unless he clutch is way worn.

As always with the crossmember and torque arm designs, you might be hearing something that can be isolated.