Speedometer Cables

Speedometer Cables on Chevrolet CMPs are one of those odd parts that do not have a ready equivalent to a standard automotive or truck application. The cable are a larger diameter than what was used on regular cars and trucks of the period. They are similar to some heavy truck applications which share the heavy and larger diameter inner cable that actually spins and a similar larger outer casing. I did find at one time a "Universal" International Truck cable kit (part # 385084C91) with had the heavier cable and outer casing it had the correct outer casing ends and could be cut to length.

The speedometer end of the cable was correct for the square drive found on either the commercial or military version CMP speedometer.

However the transfer case end was not a match for ends included in the kit. Which requires reuse of the original end. I was able to remove the old end from the broken original cable but this is a trick you can only get away with once.

Speedometer end of cable

Transfer Case end

Below are my shop notes for the cable ends - Take note that the Pattern 12 speedometer cable is shorter with the outer casing being 87 1/2 inches with the inner cable being 88 1/2 inches long. While the Pattern 13 Cable is 95" and 97" long respectively. Take note that a longer cable will work fine (5 to 10 inches) but a shorter cable will not work as the routing of the cable is tight.

One of the changes that was made between the early Pattern 13 and the later Pattern 13 is how the speedometer cable comes out of the transfer case this change was made to remove one sharp bend in the cable that was a source of broken cables. The earlier version at right shows the sharp bend in the cable and the picture at left shows the later version which is goes straight out to the side.