J&M 220 Operating And Maintenance Manual - page 46
MODEL 220
HYDRAULIC
IMPACT HAMMER
IV.
MAINTENANCE AND ADJUSTMENTS
Q. REPLACING RAM CONNECTION
Lay hammer down on flat surface or dunnage, with the trip bar up.
Loosen the set screws, in the super nut (P/N 160465).
Remove 16 3/4” SHCS in the top plate (P/N 160923) holding the cylinder rod in the
ram.
Push the cylinder rod into the actuator cylinder until the threaded end of the cylinder
rod is well clear of the ram.
Remove the nylon insert (P/N 160929), the two elastomers (P/N 160921) the two
back-up rings (P/N 160919) and the bottom plate (P/N 160925) from the ram cavity.
Remove the rod flange (P/N 160927), the super nut, the other nylon insert and the
top plate (P/N 160923) from the cylinder rod.
Carefully clean and lubricate the threads on the cylinder rod, the super nut and the
rod flange. All nuts should thread onto the cylinder rod by hand. Clean any grime
or loose pieces from cavity.
Place the top plate and one of the nylon inserts on the cylinder rod without touching
or marking threads.
Thread the super nut onto cylinder rod, with the hex heads up (toward the top
plate), until the top of the nut is aproximately 0.25 inches from the top end of the
cylinder rod threds.
Thread the rod flange, with the flange end down, onto the cylinder rod until it
contacts the super nut.
Torque super nut set screws to 233 Ft-Lbs (32.2Kg-M) (torque wrench required) in
a circular pattern. Increase torque value in three equal steps. Re-check the final
torque values at least three times to be sure it is not affected by adjacent screws.
Re-install bottom plate, the back-up rings, the elastomers, the other nylon insert
and all of the insert spacers in the cavity of the ram.
Apply Hi-Molly grease to both sides of the rod flange.
Slide cylinder rod assembly in the ram cavity until the rod flange comes in contact
with the nylon insert.
Position the other nylon insert on the insert spacers and then the top plate. Line up
bolt holes, thread and torque all 16 SHCS.
IV-13