3010 tach

[V509]

My new to me 1961 Deere 3010 diesel has an issue with the tachometer. At low idle the tachometer shows 1500rpms. Pulling the throttle lever to the stop it shows 2500 rpm’s. Pull out the stop and the tach bottoms out
No doubt the tach is way off actual rpms
The tach has the red needle..
how do I troubleshoot this? I am assuming the tach is incorrect but is there a gear where the cable attaches to the engine that could be incorrect like old school car speedometers?
I just hate throwing parts at it needlessly
Thanks

 

[JD Dave]

Most likely a defective tachometer. There are guys out there who rebuild them or new ones are available. While you're at it, replace the drive cable.

 

[Tx Jim]

I've seen a lot of good reviews on Facebook concerning Nick Barbieri & his refurbished JD tachometers.

 

[Fixingfarmer]

When I did a 4010 evergreen restorations can set the hours to what the tractor has on their new replacement tachs

It’s pretty close on the high side I guess. Usually if it’s a cable or gear it wouldn’t be reading high

 

[matthies]

Try lubing the cable and the tach.