Correct color speedometer gear

[Robert M.]

What is the correct color plastic gear for the trans and a 3.08 rear. Thanks

[Harry S.]

Re: Correct color speedometer gear

https://www.forums.ncrs.org/showthre...color&uid=7924

[Joe L.]

Re: Correct color speedometer gear

What is the correct color plastic gear for the trans and a 3.08 rear. Thanks

Robert-----


Assuming the tire size is as-original and the transmission is a 4 speed, and the car is a C2, the gear should be a "natural" (i.e. very light yellow) gear of 19 tooth count. GM #3987919.

[Robert M.]

Re: Correct color speedometer gear

Robert-----


Assuming the tire size is as-original and the transmission is a 4 speed, and the car is a C2, the gear should be a "natural" (i.e. very light yellow) gear of 19 tooth count. GM #3987919.

Thank you Joe and Harry

[James W.]

Re: Correct color speedometer gear

What is the correct color plastic gear for the trans and a 3.08 rear. Thanks

What year of Corvette?

James West

[Robert M.]

Re: Correct color speedometer gear

James, it is a 1967 with an M20 wide box and a 3.08 rear. I have 205-75R-15 radials on it. The tach appears to be dead on at speed bu the speedo is runing 10-12 mph slow.

[Wayne M.]

Re: Correct color speedometer gear

James, it is a 1967 with an M20 wide box and a 3.08 rear. I have 205-75R-15 radials on it. The tach appears to be dead on at speed bu the speedo is runing 10-12 mph slow.

Robert -- By tach "dead-on" at speed, let's assume a true 60mph, your tach should read about 2360-2400 rpm. Now you say the speedo reads 10-12% low; ie. reads 53-54 mph. Your 205-75 radials are probably only 1.5% less rolling circumference than the original 7.75's (ie. not much).

Assuming that your tach and speedo are correctly calibrated, you may find you already have the red 21-tooth gear, instead of the 19-tooth neutral (light brown). This would explain just about all that you are experiencing. But if you find the 19-tooth gear in there, then you must be out of calibration, or you will require an external speedometer adaptor to increase the cable rotation; all other gears (blue, red, etc.) will slow the speedo cable.