YZFrules

Recently upgraded a manual 3 speed to a T5z in my 70 Mach 1. New parts include pilot bearing, separator plate, flywheel, clutch and pressure plate, bell housing, hydraulic clutch system, starter, driveshaft and rear gears. Everything was installed correctly and all bolts were torqued to spec with loctite where required. Also upgraded the pedal support bushings to roller bearings. Took the car for a test drive and the clutch worked great and the transmission shifted fine. There is no noise when the car is started and idling in neutral. It starts when you release the clutch pedal when you take off and remains until you get between 35 and 40 MPH. It doesn't seem to change with RMP. When the car comes to a stop with clutch pedal pressed in, it goes away. It sounds similar to a u-joint going bad and is coming from inside the bell housing. Removed the starter and checked for damage to it and the flywheel. There was none. Rotated the engine by hand and the pressure plate bolts and dowel pins were in place. Inserted an inspection camera and there was no sign of metal shavings or anything unusual. I had a few other people listen to it and they are stumped what it could be. if anyone has any input on this, I welcome your response.

TURBOSTANG

It wasn't included in your list of new parts, but did you replace the clutch throw out bearing? Your symptoms describe a bad bearing but I'd assume it was included in the clutch.

Also, is it possible the recess in the crank is slightly different than the T5 input shaft and there's added stress on the input shaft because of it?

Just some thoughts without seeing it.

Good luck

YZFrules

Hey TURBOSTANG. The throw out bearing was replaced with a hydraulic release bearing. This eliminates the need for a fork, slave cylinder and the z-bar setup. Frees up space for headers in the future. Regarding the input shaft, the transmission when in with no issues. Didn't have to force it and got lucky with the splines matching up on the first attempt. We have done this swap on a few other cars in the past and never had any issues before. Will check the input shaft for signs of wear or damage when we take it apart though. Just trying to avoid that if possible. Thanks for the reply.

YZFrules

The Mach 1 is back on the road. Funny thing about noises is that they travel. Although it sounded like it was coming from the bell housing area, it was actually coming from the rear of the car. Put the car up on a lift and discovered the issue was the rear u joint. It wasn't seated properly in the rear pinion. The clips on the caps were hitting the tabs on the pinion. Removed the clips, put the driveshaft back in and the noise is gone. No damage to to the u joint either. Time to put some miles on the car.Next up is doing the Wilwood 4 wheel disc brake upgrade.

TURBOSTANG

Good to hear, easier than replacing the throw out bearing