Transmission Identification

[Thomas G.]

I have a Muncie 4 speed transmission that I want to further identify.
Casting #3925660 makes it a 1968-1970
But what do the following #'s mean regarding wide, close etc?
P8P05
I assume that the following # is the serial # because it was vertical 18A107163.
Any help would be appreciated.

[Patrick B.]

Re: Transmission Identification

It is out of a 68 Chevelle. Nothing on the outside identifies it as close or wide ratio. If it is out of the car, put it in first and rotate the input shaft. If it takes two and a half rotations of the input shaft to turn the output shaft on turn, it is a wide ratio. If it takes a little over two turns it is a close ratio. I think wide ratios were much more common in Chevelles.

[Joe L.]

Re: Transmission Identification

I have a Muncie 4 speed transmission that I want to further identify.
Casting #3925660 makes it a 1968-1970
But what do the following #'s mean regarding wide, close etc?
P8P05
I assume that the following # is the serial # because it was vertical 18A107163.
Any help would be appreciated.

Thomas------

Assuming it still has its original input shaft, look for circumferential grooves around the splines. If there are two grooves, it's a wide ratio (M20). If there is one groove, it's a close ratio(M21). If there are no grooves, it's a HD close ratio(M22) OR, more likely, it's a replacement input shaft in which case you can't determine the trans version by this observation..

[Thomas G.]

Re: Transmission Identification

[QUOTE=Joe Lucia (12484);865431]Thomas------

Assuming it still has its original input shaft, look for circumferential grooves around the splines. If there are two grooves, it's a wide ratio (M20). If there is one groove, it's a close ratio(M21). If there are no grooves, it's a HD close ratio(M22) OR, more likely, it's a replacement input shaft in which case you can't determine the trans version by this observation..


Thanks for your information.