1968 D-10 Tach Adjustment

Hey all!

I have a 1968 d10 series 3 with a Tachometer/Hour Meter on it. It works fine. The hours read correct.  The needle on the tach responds correctly to the RPMs of the motor.  This being said, it is in the wrong place.  When the motor is off the tach is not at the center laying at 3 and 9.  Rather it lays around 11 and 5. When I run at about 1/2 throttle the needle hits "0" at 3 and 9.  There are two screws on the bottom of the meter, btu they are only for holding the cup on it. The line (mechanical) running to the governer is in good condition.  What I would like to know is how to "calibrate" the tach so that it reads actuall RPMs.  I am going to attach a picture of the actual meter. Yes those are original Hours on Allis.  I thank you for your help!

Thanks,
Kevin

If it reads hours correctly and the tach needle swings evenly throughout the RPM range, I'd say it has jumped a tooth or two inside the tach. I have no idea how to correct that. But find it interesting.

the only way to do anything is to pry off the chrome bezel, if you look it looks as if the needle is bent or the face is bent a litttle as there seems to be a rub mark on the face where the upper left needle is by the pic anyway, and I would say this is your problem, just a guess