transmission clicking noise in reverse

[spider2081]

I installed a used transmission of unknown condition in my car. It seems fine except there is distinct clicking noise in reverse. Does anyone know what that could be? I disconnected the drive shaft at the donut and rotated the output shaft by hand, the noise comes from the back portion of the transmission. The transmission shifts smooth.

[bradartigue]

Maybe a broken tooth on the reverse gear. From someone jamming the car from R to a drive gear without stopping first...but honestly never seen it on a Spider. If it isn't something hanging off the back of the transmission (guibo, mount, shaft, u-joint) then you'll have to pull it to inspect.

[sitdog84]

I have the same problem in a 1970 spider that I just purchased, did you ever find out what the problem was??

[baltobernie]

Is the sound present with the car moving backward while in Neutral?

[spider2081]

My problem was caused by the small ball bearing that locks the speedometer drive gear to the shaft somehow came out and ended up getting caught in the teeth of the reverse idle gear. It chipped teeth off the gear. Replacing the gear and proper assembly of the speedometer drive gear cured the issue. Interesting point here is with the original transmission the speedometer indicated a speed faster than cars actual speed. With this older model transmission the speedometer displays the same speed as the GPS. The car is an 81 the transmission now is the car is the older style with studs instead of bolts holding the pan in place.

[djape1977]

speedo drive gears are various ratios and need to be coupled to diff in order to show correct reading