Haulotte HT23RTJ O, Maintenance Book

Page: 186 / 534

186 4001055250 E 10.21 USA / GB
Upper boom
Procedure of dismantling / reassembling hydraulic rotary actuators
MS0028
9. Every actuator has two sets of small punched timing
marks that indicate timing between the gear sets. The lo-
cation and appearance of the marks can vary slightly be-
tween models. One set indicates the timing between the
piston sleeve ( 3 ) and the housing ( 1 ) (photo at left), the
second set between the piston and the shaft (lower photo).
To ensure correct rotation and accurate end positions, it is
essential that the actuator be correctly timed when it is re-
assembled. The punched timing marks can be used, but
it is easier to highlight punched marks with a marker be-
fore disassembly as outlined in the steps below.
10. Prior to removing the shaft ( 2 ), use a felt marker to clear-
l y i n d i c a t e t h e t i m i n g b e t w e e n s h a f t a n d p i s t o n
sleeve ( 3 ). This will greatly simplify timing when the ac-
tuator is reassembled.
11. Remove the shaft ( 2 ) by rotating counterclockwise. As
the shaft is rotated, it will disengage from the piston
sleeve ( 3 ) and can be removed. It may be necessary to
strike the threaded end of the shaft with a rubber mallet.