powershift, how it works

[AllanC]

Can someone explain how the clutch (ok, inching pedal) function works on the 70 an 90 series powershift. specifically, are ALL the clutches released when you step on the pedal or is there some combination, and what is the function of the little valve in the bottom of the release valve?
 

[JHH]

If you click on this link, I scanned the How it Works pages from the service manual for our 870.
https://picasaweb.google.com/JHH1346/CasePowerShiftHowItWorks?authuser=0&authkey=Gv1sRgCPKLo_Op6cbulgE&feat=directlink
 

[AllanC]

Thanks very much, that's what I was looking for. The 2290 manual doesn't have it.
 

[1948 mm]

When you depress the inching pedal the only clutch used is c4 which holds the planetary drum stationary, the input shaft splined to the torque limiter discs is spinning through the planetary gears, thats why you get the whining sound in reverse and with the clutch down.