IH Tachometer

[Kuch1982]

I have a question. Im new to the old tractors, and sort of have a clue on how to read these tachs, but I just want to be sure. Can someone explain?

Also, I have an IH 706, and have an old 14ft JD double disc. What is the optimal range for pulling? RPM, speed, gear etc.

Thanks!

 

[used red MN]

The little white marks in the upper half of the black inner circle are the tach or engine rpm. 500, 1000, 1500, engine speed for 540-1000 PTO rpm in the yellow band, then 2400 max rpm.
The orange, red, yellow and green bands are travel mph in the speed transmission gears 1-4 as labeled in the horizontal white center line. (Note: in Torque Amplifier equipped tractors it is only showing the TA Direct or Hi speed) The speeds in the top half are for Lo in the range transmission, the bottom half for Hi. For example with the needle at max 2400 rpm with low range selected and 4th gear in the speed trans the orange band shows a little over 5 1\2 mph.
The optimal range for pulling an implement in my opinion is wide open, because it gets you back to the house quicker. What gear you use will be determined by your implement and soil conditions. Somewhere in the Lo range 3 or 4 to Hi range 1.

 

[Kuch1982]

The little white marks in the upper half of the black inner circle are the tach or engine rpm. 500, 1000, 1500, engine speed for 540-1000 PTO rpm in the yellow band, then 2400 max rpm.
The orange, red, yellow and green bands are travel mph in the speed transmission gears 1-4 as labeled in the horizontal white center line. (Note: in Torque Amplifier equipped tractors it is only showing the TA Direct or Hi speed) The speeds in the top half are for Lo in the range transmission, the bottom half for Hi. For example with the needle at max 2400 rpm with low range selected and 4th gear in the speed trans the orange band shows a little over 5 1\2 mph.
The optimal range for pulling an implement in my opinion is wide open, because it gets you back to the house quicker. What gear you use will be determined by your implement and soil conditions. Somewhere in the Lo range 3 or 4 to Hi range 1.

Well it was damn close to what I figured! Thank you for clarifying!! Much appreciated

 

[caterpillar guy]

That speed all varies with tire/wheel slippage though. So pulling a disk in plowed ground you will not be going quite the speed shown since you will have a good bit of slippage at the ground. On hard packed like a driveway or lane it would be pretty close.