Sundstrand Series 40 M46 Servo Piston
These pistons have been upgraded. The servo backlash adjustment is going from a self locking nut to a double nut configuration. It has a wider nut that will replace the self locking nut and is set to zero backlash like the other design. When the backlash has been set, a 225: wide nut has torque up to 18-27 ft. lbs opposed to the thicker, but want be like the lock nut.
The next change has a nonmetallic bearing ring to give the bearing preferences of the housing bore servo piston network. The rings have a split makeup and just fit into the grooves. They are behind the present grooves for the servo piston seal rings. Before you put in the bearing rings in the servo piston, the bearing rings need to discharge. You will need to wrap the bearing ring around your finger til it get to get to 1″ in diameter.
When you are ready to put it in bearing rings into the grooves, orings into the piston ring grooves and over the orings. Don’t put the piston ring near the neutral adjustment screw. Put on a light of grease or oil on the seal and bearing ring. Put the servo piston into the housing bore, the screw needs to go first, til the adjustment screw end piston ring groove is uncovered. Next, goes the second piston ring and put in the piston in the adjustment in it goes in the housing.
These are the part that are affected by the change
.335″ nut is p/n 9003535-3700
.225″ nut is p/n 9003561-3700
Bearing ring is p/n 4460477
Servo piston that has grooves for the bearing ring is 460474
Call us for more info on this change 800-361-0068