Ingersoll-Rand Jackhamer JH40, Maintenance Information

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27. Remove the four pawls (41), plungers (42), and springs (43).
28. Remove the ri fl e bar (40) from the ratchet (38).
29. Remove the locating pin (39) and seal (37) from the ratchet (38).
30. Remove the piston (49) from the front end of the cylinder (35).
31. To remove the ri fl e nut (50) from the piston: Hold the piston in a
vise, insert an old ri fl e bar in the ri fl e nut and turn clockwise to
unscrew. (The ri fl e nut has left-hand threads).
NOTICE
The old ri fl e bar may require several good blows with a copper
hammer to loosen the ri fl e nut. Block-up under the head of the
old ri fl e bar before striking it to prevent it from breaking.
32. Press the piston stem bearing (51) out of the cylinder.
33. If worn and replacement is necessary, press the piston stem
bearing sleeve (52) out of the piston stem bearing (51). The sleeve
is press fi tted in the bearing, and should not be removed unless
replacement is necessary
Inspection and Repair
Clean disassembled parts in a suitable solvent.
WARNING
Use only proper cleaning solvents to clean parts. Use only
cleaning solvents which meet current safety and health
standards. Use cleaning solvents in a well ventilated area.
2. Replace the ri fl e bar or ri fl e nut if the fl utes are worn
approximately 1/16 in. (1.6mm). If a 1/8 in. (3.2mm) shim can slide
between the sides of the fl utes of the ri fl e bar and ri fl e nut, either
one, or both, is excessively worn.
3. The rotation pawls can be reversed when the edges on one side
become rounded. When the edges on both sides have rounded
to approximately 1/16 in. (1.6mm) radius, the pawls should be
replaced.
4. Replace weak pawl plunger springs.
5. Replace the rotation ratchet when the teeth are rounded to 1/1 6
in. (1.6mm) radius.
6. When a 0.003 in. (0.076mm) feeler gauge can be inserted
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between the valve and valve guide, or between the valve
and valve chest, one or both parts are worn and should be
discarded. To determine which part is excessively worn, various
combinations of new valve parts should be assembled. The worn
parts can be determined by means of a feeler gauge.
7. To check for a sticky valve, clean the valve parts and assemble
the valve chest complete without oil. Shaking the chest should
cause a clicking sound as the valve moves back and forth. If the
clicking cannot be heard the sticky valve must be replaced. Be
sure to disassemble and oil the valve parts before reassembling
for operation.
8. Examine the piston and ri fl e bar for heat checks resulting from
improper lubrication. If heat checked, replace these parts in order
to prevent damage to other parts.
9. Check the cylinder and piston for wear by inserting a 0.007 in.
(0.178mm) feeler gauge between them. To determine whether
the piston or cylinder is worn, insert a new piston in the cylinder,
and check the clearance with a feeler gauge.
10. Check the piston periodically, to be sure that the striking face
is in proper condition at all times. If cupped, it can be refaced
by grinding. Regrind the striking face fl at and square without
burning, remove as little metal as possible and not more than
1/16 in. (1.6mm). This is the limit which will insure a hard striking
face. If the striking end of the piston is cupped, check the shanks
of the steels that were used to be sure the striking ends are fl at
and square.
11. Replace the piston stem bearing sleeve when a 0.007 in.
(0.178mm) feeler gauge can be inserted between the piston stem
and the sleeve.
12. Replace the chuck nut when the fl utes in the nut are worn
approximately 1/16 in. (1.6mm).
13. Replace the chuck when the ends of the chuck bore are worn to
the extent that the drill steel shank cocks in the drill assembly.
When the chuck is worn, the drill steel can no longer be held in
line with the piston, and the loss of support for the shank allows
the piston to strike the shank on an angle, damaging the piston,
shank, and tube.
Assembly of the Tool
Press the piston stem bearing sleeve (52) into the piston stem
bearing (51).
Align the assembly rod half-holes in the piston stem bearing
fl anges with the half holes in each side of the cylinder body and
press the piston stem bearing (51) into the cylinder (35). This is
a tight fi t; make sure the bearing is started squarely and that the
cylinder is supported.
Screw the ri fl e nut (50) into the piston and slide the piston into
the cylinder.
NOTICE
The ri fl e nut has left-hand threads; turn counterclockwise when
installing in piston. Use an old ri fl e bar as a wrench to tighten
ri fl e nut.
Assembly of the Valve Chest
Install the valve (46) over the valve guide stem (47).
Install the valve chest (45) on the valve guide (47).
NOTICE
Make sure the valve is free, check by shaking the valve chest. The
valve should click open and shut when free of oil. After the
clicking noise is noted, oil the valve.
3. Insert the rotation ratchet dowel pin (39) in the groove provided
in the O.D. of the valve chest (45). Install the complete valve chest
assembly in the cylinder (35) aligning the rotation ratchet dowel
pin (39) with its groove in the cylinder.
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2.
3.
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Assembly of Rotation Parts
4. Place one rotation pawl plunger spring (43) and one rotation
pawl plunger (42) in each of the four holes in the ri fl e bar (40).
5. Slip one rotation pawl (41) into each of the pawl housings in the
ri fl e bar (40).
6. Compress the four rotation pawls (41) and slip the rotation
ratchet (38) over the pawls.
7. Align the dowel pin groove in the rotation ratchet (38) with the
dowel pin (39) already in place in the cylinder (35) and slide the
rotation assembly into the cylinder.
8. Install the mu ffl er cap (34) on the handle end of the cylinder (35).
9. Slide the mu ffl er (33) over the cylinder so that it seats against the
mu ffl er cap at the back end and on the piston stem bearing at the
front end.
10. Screw the chuck nut (56) into the chuck driver (55).
NOTICE
The chuck nut is fi tted with left-hand threads. Turn
counterclockwise to screw chuck nut into driver. An old piston
can be used to tighten the chuck nut.
11. Slide the chuck (54) and chuck driver assembly into the fronthead
(58).
12. Align the assembly rod holes in the fronthead fl ange with the
half-holes in the cylinder and piston stem bearing and slide the
fronthead (58) into position.