'55 Speedo Gauge Issue

Before we did a cosmetic restore on the CJ5, we realized the speedo cable was not installed.



Once we installed a new cable and drove it some, the speedo needle would become erratic and bounce all over. This eventually caused the needle to break.



Looking for a cause at this time- bad speedo gear inside the Dana 18 transfer case? Can't think of anything else.... right?

We either need to replace speedo gauge with a rebuilt, good (used) or try to superglue needle back. Since both FUEL and TEMP gauges work, that will likely be our first attempt.

Thanks!

 

Usually a jumpy cable is the core catching and winding up like a spring in the sheath, then releasing. Suspect this is hardened grease and dirt in the cable, or total lack of lubrication. If the cable core is not broken, you should be able to fix it by cleaning it.

If you take the speedometer cable off, the core will slide out of the sheath. I suggest you clean both the core and sheath with some clean solvent then lubricate the core before you put the assembly back. Opinions vary about what lubricant to use. I'd probably use white lithium grease, but there are products specifically for this purpose.

 

All of the above, plus it is crucial that the inner core of the cable not be too long. It must have a slight amount of end clearance when the outer sheath is tightened.

Especially if a "cut-to-length-yourself" universal core replacement is being used.

A way to check this is if the erratic behavior stops when the outer sheath nut is slightly unscrewed.

If gluing the needle, remember it was precision balanced to read true. Unfortunately the speedo for that year was somewhat rare and may be hard to replace.

 

Even if you used a new cable it should be pulled out of the sheath and lubricated before installation.

Yep those "Willys" labeled speedometers are very hard to find.

 

Yes, thats an early 6 volt King-Seeley speedo. The cable is the likely cause of the erratic behavior as mentioned previously. Your speedo probably has thickened grease in the mechanism in the drive head too. In your first photo, the needle is resting about 5 mph, and the other photo with the broken needle has it stuck past the 10. Your speedo needed service before you hooked up the cable.
Donny