[alfacharlie]

Bertone friends,

On the way to improve my 66 stepnose Veloce, I'm bothering with some apparent transmission noises. The GTV has been upgraded with a new clutch, a revised gearbox and a different rear axle + differential as the old one had a 8/41 ratio diff. The exhaust has gotten a new mid muffler and rear muffler.

Noise 1: at highway speeds, between approx 60 mph - 100 kph and 90 mph / 140 kph, a quite loud, low rumbling sound takes over from the lovely engine song. The sound is like wow wow wow wow wow... it was already present before the clutch, rear axle and exhaust change. I'm still in doubt whether the noise is caused by the transmission or the exhaust system.

Noise 2: when driving and lifting the throttle fully or almost fully, a slight high frequent rattling sound comes up, like tac tac tac tac tac. When slightly depressing the clutch, or re-applying throttle, the sound disappears. The Veloce's clutch is mechanically operated through a cable. Might the sound have to do with cable adjustment?

Your opinions are most welcome.

Cheers,
Charles

 

[cliffordh]

Is the new diff an LSD? They do sound quite different.

Have you changed the trailing arm rubbers? These can radically change the amount of road, bearing and diff noise you hear, especially nylon bushes.

 

[Erik]

What about the drive shaft*), center bearing and joints - front, center and rear
*) Could be out of ballance or not fitted to the flances as before disassemble.
Erik

 

[Bertonemorten]

Worn "olive" on gearbox output shaft or worn bushing in front end of driveshaft ?

 

[alfacharlie]

In the event it turned out that both universal joints on the rear prop shaft section were worn and appeared to be frozen solid to the shaft rather than able to move/turn freely. An overhauled prop shaft section has been mounted now and the transmission noise has gone

 

[jcslocum]

That's good news!!! Another happy ending