Wacky Tach!

[Dusty]

I have had a lot of experience with a similiar problem in one type of car that I have owned in the past. The cable is wound with a bunch of layers of steel "threads" over a single core. The first layer is wound clockwise, second layer is counter clockwise, third clockwise, etc. With the cable rotating all the time, a wire in the bundle will eventually break, and snag the casing that the cable turns in. When this happens, there is a rough spot in the casing that is grabbing the cable, putting tension on it, until it springs free. If you look inside the casing, you might find a thin plastic lining that you can pull out. Many times, the cable will just be binding on this liner. The reason that the original drive mechanism broke, was the cables binding putting stress on the part. You should replace cable and casing at the same time to eliminate premature failure of the new sending unit. If you want to test the head itself, use a variable speed drill on the end of the cable shaft and see how well the tach works.
Dusty

 

[Kubota3710]

The RPM on my L3710 is still 3000 plus when its running. The cable seems to spin freely with no damage on inspection.

I took apart the easy checker and got the tach head out. It looks like the cable turns a clutch mechanism that converts the spinning cable into an RPM indication. When I spin the TACH slowly with an allen wrench, the clutch seems to be sticking and the RPM creeps up to the same 3000 RPM plus. I've blown it out with air, but still sticking. After I put on my glasses..., I could see that there is wire (a spring?) coming undone around the shaft at the base of the clutch.


I think I am headed to the kubota dealer tomorrow for a new tach indicator.

Anyone know how to get the hour meter on a new tack to read 731 hours?

Rich

 

[wushaw]

Just write it down in the owners manual or wherever you keep your records as to when the tach was changed then keep on tractoring.