case 580d tachometer question

chrisdvorak · Dec 18, 2012

I am trying to get the tach working on my 81 case 580d. I had the dash apart today and found that the gauge itself is working but there is no cable attached to the back of it, I'm not sure if the previous owner removed the entire cable or what but I cant seem to find it. does anyone know where the tach cable attaches to the engine? and also if the cable is inside the wiring harness or separate?

-thanks chris

Eyecatcher · Dec 18, 2012

The tach cable runs from the back of the tach down to the right side of the engine block behind the alternator, if its like my 580C. Tach drive is very expensve to replace

chrisdvorak · Dec 18, 2012

Eyecatcher said:
The tach cable runs from the back of the tach down to the right side of the engine block behind the alternator, if its like my 580C. Tach drive is very expensve to replace

thanks, I will check behind the alternator and hopefully I can find it, is the drive you are talking about number 1 in this diagram?

Parts for Case 580D Loader Backhoes

chrisdvorak · Dec 18, 2012

I managed to get a pic of the right side, should the drive be coming out of what looks like a little tube coming out of the block?

BukitCase · Dec 19, 2012

You found it - just in case, here's your pic back with confirmation. That little knurled ring at the lower end of the indicated part is the drive gear - hopefully it's in good shape 'cause it's twice what they want for the cable.

HTH... Steve

chrisdvorak · Dec 19, 2012

Thanks for the help! Does the cable go inside the harness or is it separate going up to the dash?

Eyecatcher · Dec 19, 2012

The cable runs by itself up to the dash. Unscrew the knurled knob on the crankcase fitting, and see if you can see or feel anything turning when the engine is running. If not, you will have to replace the drive assy and the entire cable assy. The drive assy is difficult to remove from the block. but it will come out. Expect to spend about $150 to replace the pair. The hobbs meter has a 100ths wheel that is covered, so if you get it repaired, the first time it turns over all the digits, and looks like the hobbs is no longer working, relax, after 1/10 of an hour you'll see it move. A mini tach is probably a more economical fix.