Transmission Growl 66BB

[John M.]

The transmission in this 66 was rebuilt before we got the car. It's quite noisy when decelerating at low speeds in 1st and 2nd. We took the side cover off last night and everything in there looks new or in good shape, new sliders, synch rings, forks, etc. Any ideas why it would be so noisy? The gear oil is clean but looks to be lower than normal viscosity.
Thanks
John McRae 30025

[Rich P.]

Re: Transmission Growl 66BB

Joe,

since this was done before you had the car do you know if the used M-22 gears? Also did you check the front to rear play in the counter gear? These are just a couple of quick things that come to mind.

Rich

[John M.]

Re: Transmission Growl 66BB

Thanks Rich,
The M22 is a possibility. The guy we bought the car from ran a transmission business. I have photos of M22 gears and will check. The countershaft is nice and tight.

[Edward J.]

Re: Transmission Growl 66BB

John, the maybe some sort of bearing problem in the trans. causing movement and making the gears clash. any movement in the input or output shaft or counter shaft will likely be the problem.

[Alan D.]

Re: Transmission Growl 66BB

And pilot bearing in crank if those checks fail, not likely but

[Joel A.]

Re: Transmission Growl 66BB

If it is only "growling" when decelerating, I'd suspect too much endplay on the mainshaft. A loose rear bearing in the adapter/rear plate could cause that.
The roller/needle bearings on the countershaft/cluster gear can make weird noises, too, if they aren't assembled correctly, or if the shaft itself has wear...
If it also growls while driving/upshifting, it is probably a mis-match of the gears.
M22s have a distinctive "growl" to them in all gears except 4th...they don't call em rock-crushers for nuthin!