The original tachometer is a chunk of junk. I used to save them and now have over a dozen broken ones. The tachometer from a Jeep Cherokee will work if you're creative. I'll post pictures once its installed, but I did figure out how to install it. I used the plastic from the stock clock, removed the guts and shaved down the plastic so it was just the front plate, then etched a half circle from it using a mason jar lid as a stencil. That cut was the hardest part, but lots of passes and patience can make a very neat cut. The half circle and flat bottom exposes the needle and its scale, while providing smooth black filler to make it look original.
The 1992 Jeep Cherokee tachometer comes out of the Jeep dash as a unit. There are three screws in the back that conduct electricity from the copper circuit paper. You can hook the input wires directly to those screws and use it independently.
The aluminum face is too big, but it is easily cut down to size. First I cut off the lip around the edge. Then I used the plastic clock face to mark where two alignment holes need to be drilled at the bottom, as well as to mark the excess that needed to be further trimmed. With care, the end product will look clean and original.
I don't know for sure if that tach works with a 4.2 distributor, but it likely does. I am using it with a fuel injection conversion.
Topic: Replacing the clock with a tach (Read 12069 times)