aftermarket Speedo

[juanprado]

Thinking of replacing my stock mechanical speedo since mine does 69/70. I know they have the electronic 80mph in the later models.

My thought was to use an aftermarket like this autometer #2690 since it mechanical and change the bulb to 24v . Anyone gone this route?

 

[lindsey97]

won't work, wrong color.

 

[lindsey97]

Looked up the specs on summit racing for the autometer 2690.

diameter of instrument: 3 3/8". Input is 5/8"-18 threaded adapter with .104" square drive.

I looked at a Stewart Warner speedometer I have out of a M939 5 ton, it measures 3 3/8" in diameter, has 5/8" thread input on the back, with a square drive tang.

I am curious what the input speed is of the 5 ton speedo and the autometer 2690. Could they both be 0-1000rpm like other class 8 trucks with mechanical speedometers?

 

[juanprado]

Looked up the specs on summit racing for the autometer 2690.

diameter of instrument: 3 3/8". Input is 5/8"-18 threaded adapter with .104" square drive.

I looked at a Stewart Warner speedometer I have out of a M939 5 ton, it measures 3 3/8" in diameter, has 5/8" thread input on the back, with a square drive tang.

I am curious what the input speed is of the 5 ton speedo and the autometer 2690. Could they both be 0-1000rpm like other class 8 trucks with mechanical speedometers?

On the hmmwv I think it is all good, direct mechanical drive. Not sure on the M939, I know the A1 & A2 use a different 90* adapter on the cable due to the tire size to make the ratio correct but the speedo is the same unit. Should work ok as long as the correct tire size matches the ratio of the adapter, Speedo should display correct speed.

The autometer uses a plain 194 wedge bulb but those are out there in 24v led in many colors.

 

[Action]

Speed is adjusted by a plastic gear inside the transfer case below the 90* elbow. I think I have seen 3 different gears. Only one bolt holds it in.

 

[86humv]

T/C gear is orange 35 teeth for 2.56 diff's, red 36 teeth for 2.73, and red and 40 or more teeth for 3.08's.

 

[wheelspinner]

Whew, Juan you had me a little worried with the title..........

 

[juanprado]

Whew, Juan you had me a little worried with the title..........

now, now, no mentally disturbing imagery here........