If you have ever thought of swapping a late-model transfer case and/or transmission into your earlier Jeep but the new parts can only drive an electronic speedometer and you didn't want to swap out your stock mechanical unit, you are not alone.
It is no secret we are always putting parts into Jeeps that might not necessarily belong there and in the past we have used Performance Transmission and Parts (PATC) for other oddball applications as well. So, when the time came to put our stock speedometer back in the Jeep and make it functional, PATC was on the top of the list. The company's Cable-X by Abbot Enterprises is a unit that takes an electronic speedometer signal from a tone ring and transforms it into a mechanical signal.
There are less expensive units out there, but frankly, we were concerned about the quality and longevity of the cheaper units. Any time you have an electronic motor running something mechanical for extended periods of time, you should look at how heavy-duty the thing is. The Cable-X uses a motor that is bigger than many drill motors, and we know that PATC stands behind whatever they sell, so we ordered up a unit.
What we got was a surprisingly solid black box, a speedometer cable core replacement, a very detailed instruction/installation manual, and some great tech support on the phone.
Locating the unit in the Jeep took some thought, but after running a switched positive and a ground to both the sensor in our 241OR and the Cable-X and then hooking the remaining wire from the transfer case to the input on the Cable-X we were ready to go. Another cool feature of this unit is that no matter what size tires or what gears we go to in the future, with just flipping a few switches, our speedometer will be back within the two percent tolerance that the Cable-X provides all day long.
All in all, the Cable-X is a great way to retain the stock look of your Jeep dash (it'll work for CJs, early YJs and all kinds of pre-'90 Jeeps) while giving the ability to swap in almost any modern drivetrain and not having to worry about whether or not your speedometer will work when you are done. Check out how we installed it for some off-road specific ideas that can help with the install in your Jeep.
We mounted the unit inside...
We mounted the unit inside the truck to keep dirt and water out of it. At the bottom of the picture inside the box is the electric motor that now drives our speedometer. To the top of the picture, you can see a series of white switches which are the way to adjust the unit to your particular transmission, tire size, and gearing. The actual Cable-X measures roughly 2x4x6 inches, and the company provides it with an output fitting that fits your stock speedometer cable.
It turns out that our Comanche...
It turns out that our Comanche has a somewhat unique speedometer cable fitting at the speedometer head. Normally PATC will provide a new speedometer cable to attach the unit to your speedometer. In our case, the company didn't have the fitting we needed, so it provided this repair core that we then cut to the needed length.