loud chattering mt82

[JJ.coyote]

Hi guys, I have owned my mustang for about 2 years now, I bought it used and have been dailying it ever since, it has about 104,000 miles already, I recently had clutch, flywheel, throwout/slave cylinder, pilot bearing all replaced with oem ford parts and the mt82 is still making a racket. I had the fluid replaced with bg synchroshift II. Its not whining and the gears are all going in fine, it just sound like a diesel pickup at idle lol, the rattle sound goes away I press down on the clutch, any ideas what could be done? I had thought it was throwout bearing issue but that didnt change a thing.

 

[me32]

What year mt82?

 

[JJ.coyote]

2012, I bought the car used 2 years ago so
I'm not sure if it's the original mt82

 

[Norm Peterson]

Probably a resonance between gears in the transmission being excited by the engine running. When you declutch, you've rotationally disconnected the crankshaft from the transmission's input shaft and everything behind it. The transmission's input shaft stops turning, leaving nothing in the transmission trying to rotate and rattle against anything else in there.

Know that any "constant" engine speed really isn't constant when you look at rpm vs crankshaft position over any single crankshaft revolution. It varies a bit as individual cylinders fire and during the pauses between firings. The flywheel, pressure plate, and harmonic balancer do smooth this out some, but not completely. Dual-mass flywheels do a better job, at some costs in weight (heavier) and long-term durability.

An idle rpm adjustment may be all it takes. Try holding engine rpms a little higher (clutch engaged, transmission in neutral) and see if the rattle goes away.


Norm

 

[JJ.coyote]

Probably a resonance between gears in the transmission being excited by the engine running. When you declutch, you've rotationally disconnected the crankshaft from the transmission's input shaft and everything behind it. The transmission's input shaft stops turning, leaving nothing in the transmission trying to rotate and rattle against anything else in there.

Know that any "constant" engine speed really isn't constant when you look at rpm vs crankshaft position over any single crankshaft revolution. It varies a bit as individual cylinders fire and during the pauses between firings. The flywheel, pressure plate, and harmonic balancer do smooth this out some, but not completely. Dual-mass flywheels do a better job, at some costs in weight (heavier) and long-term durability.

An idle rpm adjustment may be all it takes. Try holding engine rpms a little higher (clutch engaged, transmission in neutral) and see if the rattle goes away.


Norm

I'll give it a shot later today, I do know that the sound drowns out while driving.