Replace 92 - 93 Speedometers
© Copyright 2000 - 2007 Chuck Kopelson 05/05/2005
Updated February 7, 2008
The 92 and 93 Hummers have mechanical speedometer. This for me and others has caused problems with it failing. I had the problem repaired a few times, but within a short time it failed once again. The problems started out with the odometer dancing around and it got wose from there. Once, right at the dealership after it was fixed, it started dancing around and within a mile it failed.
The problem was the speedometer cable that went from the transfer case to the dash had too many tight bends and was a little too short. The bends in the cable caused tension in the rotating core in the cable. The 90 deg. elbow broke 3 times at the transfer case. The last time the gears in the transfer case stripped.
Thanks to AMG I have now changed to an electronic speedometer that is used in the 94 and newer Hummers. I told them that I would do the work of installing the new odometer because this was not a direct replacement item and I did not want the dealership try it.
The electronic sending unit AMG sent to me would not fit directly in my transfer case and the service manual did not show me how the new sending unit was supposed to mount. But from what I could find out, the gear inside the transfer case that is seen in the right photo above would have to be replaced, and that was a part I did not have.
So instead of using using factory way of picking up the speed, I mounted 8 very strong magnets to the drive shaft and mounted the sending unit to a angle bracket, and mounted the bracket to the cross member for the transmission.
I Later found a sending unit that uses the gear inside the transfer case. VDO part # 340-011 VDO also makes some nice programmable Speedometers with resetable trip odometers.
The new speedometer fit in the old speedometer mounting hole just fine. I had to run a single twisted cable to the sending unit and got my power from the fuel gauge & volt meter too power the speedometer. Set the dip switches in the speedometer to reflect the correct speed using a GPS unit. Now I have a nice, smooth operating speedometer.