CHAPTER 4
Maintenance Procedures
S36 ROCKDRILL | PARTS & SERVICE MANUAL
January, 2021
12
Assembly Guide
Before commencing assembly:
All components should be washed in a solvent and
carefully dried by blowing or wiping with clean cloths.
Each component should be lubricated with rockdrill oil
as it is assembled. Reassemble carefully, do not
‘drive’ components that should be pressed together.
Make sure sliding and rotating components are
carefully aligned to avoid jamming.
1. Press the chuck bushing Ref. 70 into the front of
the chuck gear Ref. 69.
2. Press into place the front cylinder liner Ref. 63
using the piston as a guide.
3. The feed nut Ref. 64 should be assembled into
the front cylinder. Push the nut into place from
the rear of the machine making sure that the flat
on the flange lines up with the cylinder wall. Fit
the lock washer Ref. 65 and the nut Ref. 66 on
the threaded portion of the nut.
4. Insert the piston Ref. 62 into the rear of the
cylinder.
5. Assemble the valve box. Carefully fit the valve
Ref. 24 over the plug Ref. 25 and valve making
sure the groove for the dowel is correctly aligned.
When the box Ref. 22 engages the plug, press
the two components together until the flange of
the plug meets the front face of the box. It is
important to check that the valve can move freely
inside the box. If it does not move freely something
is wrong and should be checked.
6. Insert the valve assembly into the rear of the
cylinder using the locating pin Ref. 23 to make
sure the ports line up inside.
7. Fit the dummy rifle bar Ref. 20 into the bore of
the valve assembly with the seal Ref. 19 making
sure it is fitted into the recess at the rear.
8. Fit the backhead spacer Ref. 21 into the rear of
the cylinder making sure it is located squarely on
the rear of the valve assembly and the dowel.
9.
Rotation motor and drive sub assembly:
(a) Fit the needle roller bearings Ref. 54 into the
back plate. Fit the flange bushings Ref. 38
into the front plates.
(b) Push the drive pinion Ref. 39 through the left
hand bore in the motor front plate Ref. 51
when looking from the rear.
(c) Fit the keyed rotor Ref. 55 and its key Ref.
37 to the drive pinion.
(d) Assemble the compound gear Ref. 41 onto
the compound gear pinion Ref. 42 using the
eight cap screws.
(e) Fit the compound gear pinion through the
right hand bore in the motor front plate
from the front.
(f) Assemble the needle roller bearings Ref. 52
and the spacer Ref. 53 on the pinion shaft.
(g) Fit the air motor housing Ref. 57 over the
rotors and assemble the back plate Ref. 51
into the ends of the shafts Ref. 39 and 42.
(h) Attach the assembled motor to the reduction
housing by means of the seven bolts and
nuts. Make sure the locating sleeve Ref. 56
is fitted correctly over bolts. Spring washers
are fitted beneath both the head of all the
bolts, and under the nuts.
In addition spacer washers are fitted beneath
the spring washers on the two large lower
bolts Ref. 26.
(i) Tighten all the nuts Ref. 43 to a torque of
110 Nm (81 ft-lb) and Ref. 44 to a torque of
80 Nm (59 ft-lb).
(j) If the idler gear Ref. 50 is to be reassembled
hold the gear with its bearing Ref. 49 already
fitted into place inside the housing. The shaft
Ref. 47 should be pushed into the housing
from the front and through the bore of the
bearing inside the gear. The shaft is secured
with the screws and washer.
10. Fit the assembled air motor and reduction
housing over the front cylinder Ref. 67 already
fitted into the main cylinder Ref. 58.
