Hi Out There
Does Anyone Have Any Experience On How To Shift An Eaton 2 Speed Rear Without Grinding The Heck Out Of It? I Have A 72 F600 And Upshifting Is Not Too Bad But Down Shifting Seems To Be The Problem.

Thanks For Any Help.
Stevieboy330

 

Stevieboy330,
I have quite a bit of experience driving a dump truck. The 2 speed rear is an exceptional upshift, as you have learned. It is an EXTREMELY tricky downshift. It is nearly impossible to downshift the 2 speed on a downshift of the main transmission. In other words, it can be down shifted on the upshift of the main transmission, but not downshifted on a downshift. I worked with guys who had driven those things since they were invented, and I don't know anybody who could downshift on a downshift. Anyway, here's what I used to do. The truck I drove was a '61 International VF 10 wheel dumptruck with a non-synchronized transmission. I would double clutch on the upshift and lightly engage the clutch to make sure I shifted correctly, then I would disengage the clutch and pop the two speed shifter. I would bring the engine RPMs up a little and feather the clutch a touch to get the engine synchronized with the rear and to allow the gears on the rear to mesh, then I would engage the clutch. As far as a downshift of just the 2 speed, I would only do this on an upgrade, not as a way to downshift and slow down. Forget trying to do that. Anyway, as your truck is climbing a hill and the RPMs are dropping, hit the button to shift. It won't shift until the torque is taken off the driveline. Depress the clutch and bring the RPMs up so the rear is synchronized with the engine. You'll need to feather the clutch, then engage the clutch fully. All this happens in like seconds, and it takes lots of practice. Good luck. The good thing is that those Eaton 2 speeds are generally super tough. By the way, they used to call an upshift of the main transmission and a shift of the two speed a "split shift". You could effectively double the number of true gears the main transmission had.

 

I had one experience driving a two speed rear...it was terrible. Been like 15 yrs now.

I'll take my twin stick Mack ANYDAY!!!!

 

We have this on the visor of our F600. E-mail me if you would like a better quality pic for printing.

 

The International I drove had those same sort of instructions on a sheet metal tag that was riveted to the dash of the truck. The instructions were about as long as the Ford's and just as inadequate. There's nothing trivial about downshifting the two speed Eaton on a split downshift.

 

The International I drove had those same sort of instructions on a sheet metal tag that was riveted to the dash of the truck. The instructions were about as long as the Ford's and just as inadequate. There's nothing trivial about downshifting the two speed Eaton on a split downshift. Notice there is no instruction about how to downshift the Main and downshift the 2 speed!!!