CJ speedo

I think my speedo that came with the Jeep is knackered, the dial needle sits at 20 MPH mark instead of zero at rest? Is my assumption right? Any ideas where I would find a replacement, mine is the old style without the fuel gauge and temp gauge.

Also how is the speedo calibrated for different gearing/wheel sizes

 

You assume correctly but I'd pull it out and try clean it up/lube it first. Might just be years of accumulated dust/?? preventing the needle from returning to the pin or it might just be toast. Does it seem to work OK otherwise?
The speedo is calibrated by the size of the driven gear or the gear on the end of the cable at the transfer case.

 

pm sent

 

At present I have no way of checking if it is working at all as the jeep is in pieces, I would say based upon observation that the unit has not been used for a number of years (say 10) due to an alternative powerplant and box. I'm just trying to accumulate the necessary parts so my rebuild goes smoothly.

As for calibration do I need to get a certian drive gear for my setup (tire size/diff ratio)? If so who sells them?

 

I suggest you remove the speedometer head and do some careful cleaning and lubrication with a very light machine oil. The needle turns on brass or jeweled needle bearings, and is easy to break with rough handling.

You can use your electric drill to turn the speedometer cable.

There's no source for aftermarket speedometer gears that I know of. You can try and find one from a scrap transfer case with the ratio you want. Stewart-Warner used to make an inline transmission that allowed you to adjust the cable speed. I expect these are no longer available, now that both OEM and aftermarket electronic speedometers are common.

 

Ok I'll try and open it up, give it a clean etc

 

Ok well I opened it up and unfortunatley even after cleaning its still not reading zero at stationary so I spose I'll have to find a replacement

 

What did you do to clean it? Will the needle move at all? What did you oil it with?

I spent a few days working on mine when I redid it.........

 

Check e-bay

 

I opened it up and cleaned all the moving parts down with methys as I was not sure about using any other type of degreaser, there was a few bits of crap in there but suspect that this was not the first time this gauge had been opened and played with by the marks I found whilst opening it. I just used a very light machine oil to relubricate the parts but unfortunatley it didn't not reset to zero. Yes everything inside looked to be free and moving.

 

If someone had this speedo head apart and tweaked the return spring, it seems very unlikely that you will fix it. If the cup turns freely but the needle does not return fully, I suspect the spring has been bent/distorted/stretched.

Another possbility is that the needle has been turned on the hub. You could try to remove the needle by carefully pulling straight up on the needle, then replacing it at the proper zero location. May as well try - nothing to lose at this point.

There are speedometer shops that likely could fix it, but since these speedometers are available on the aftermarket, a new part will almost certainly be less expensive than fixing this one. One possibility would be to buy a new speedometer head and graft your face plate onto the new mechanism. This would require removing and replacing the needle - so I'd try that on the old speedometer head first.

 

No mine does have the gauges at the bottom of the speedo but they were not used with the replacement engine (not Jeep) so were blanked using a piece of black card glued over them (effectively hiding them), I will try and remove the needle as Tim suggests, everything inside looks ok but hard to tell if damage was done originally.