Steering Cylinder - TM-10-3930-243-340221

f. Reassembly. Refer to figure 3-131 and

hex socket setscrew in packing nut. With a spanner

r e a s s e m b l e hydraulic steering cylinder as described

wrench loosen and unscrew packing nut.

above.

(3) All internal parts can now be taken out cm

g. Test.

the piston rod.

(1) P a c k i n g d r a g t e s t .

( 4 ) Hold rod end with pin through the eye to

(a) With cylinder horizontal, fill rod end of

p r e v e n t turning. Protect rod from damage. Remove

t h e cylinder with oil.

nut on piston end, slide parts off removing O-rings.

(b) Open head end part of the piston to the

( 5 ) Thoroughly wash all parts in solvent (Fed

atmosphere.

P-D-680) and wipe or blow dry.

(c) W i t h r o d e n d u n d e r n o l o a d e x c e p t

(6) Install new back up rings and O-rings with

n o r m a l seal and wiper drag, pressurize the rod end

a minimum amount of stretching. Thoroughly

of the cylinder and record the maximum pressure

l u b r i c a t e all seals and packing with hydraulic oil.

reached before piston moves.

(7) Reinstall bushing into retainer and slide

(d) Repeat the above for head end of the

packing nut and assembled retainer onto piston

cylinder.

rod.

(e) The piston may be operated as necessary

(8) Install new packing and rider on piston

for wear in.

h a l f and slide on rod, slide O-ring into place and

(f) Piston rod will extent with maximum of

lubricate. Install washer, slide next O-ring into

15 PSI on piston. Piston rod will retract with

place.

maximum of 25 PSI on rod side of piston.

( 9 ) Check cylinder bore to be sure it is clean

(2) P i s t o n L e a k a g e T e s t .

and free of any contamination.

(a) Fill cylinder with oil. Seal rod end and

(10) Use a length of brass shim stock to guide

load the head end of the piston to not less than

packing over threads. Apply another coat of

2000 PSI and hold this pressure for 15 minutes.

lubricant to all exposed seals and carefully insert

(b) Measure and record the travel of the

a s s e m b l y into shell. Push retainer into position and

piston during the 15 minutes.

tighten packing nut.

(c) Repeat procedure for rod end of

(11) Tighten setscrew firmly in place and

cylinder.

reinstall cylinders in truck.

( 1 2 ) Actuate hydraulic system, remove blocks

(d) Maximum piston rod drift not to exceed

a n d cycle through all functions to purge air from

1 inch per hour.

system.

h. Adjustment. The steering cylinders must be

adjusted so each steering cylinder has an equal

NOTE

amount of travel of the piston rods. The tie rods

Internal loos of pressure in the cylinder can be caused

must be adjusted to no toe in or toe out. Retract the

by a damaged O-ring between the piston half and rod

or the piston packing.

steering cylinder rod shaft. Mark (with tape) the

NOTE

rod shaft against the face of the cylinder. Fully

Cylinders having the spherical bearing in the ends

extend the cylinder rod shaft and measure this

have a press fit but are also staked to prevent working

d i s t a n c e from. the face of the cylinder to the mark

loose.

m a d e with the rod retracted. Mark this distance

d. Disassembly. Refer to figure 3-131 and

(with tape outside the mark). Retract the

d i s a s s e m b l e h hydraulic steering cylinders.

c y l i n d e r rod to the stroke (or edge of tape). The

e. Inspection.

w h e e l s must be in line. Screw on the cylinder rod

( 1 ) Inspect cylinder rod for nicks and damage.

e n d until the cylinder rod end lock pin can be in-

Damaged rods will shorten packing life.

serted in the lock pin hole. Torque the rod end

(2) Inspect shell for cracks and damage.

locking bolt to 40 ft. lbs. Adjust other steering

(3) Inspect piston for nicks and scratches.

cylinders in a similar manner.

(4) Remove nicks and scratches with crocus

i . Installation. Refer to figure 3-130 and install

cloth.

hydraulic steering cylinder.

(5) Replace a defective part.

3-183