HDA SERIES WALK-BEHIND TROWEL • OPERATION MANUAL — REV. #0 (12/1/17) — PAGE 39
MAINTENANCE
Trowel Arm Removal
1. Each trowel arm is held in place at the spider plate
by a Zerk grease fitting (hex head bolt) and a roll pin
(Figure 62). Remove the Zerk grease fitting and the
roll pin from the spider plate.
Figure 62. Trowel Arm Removal
2. Remove the trowel arm from the spider plate
(Figure 62).
3. Carefully remove the trowel arm bushing (Figure 62)
and set it aside.
4. Examine the trowel arm bushing, and clean it if
necessary. Replace the bushing if it is worn or
out-of-round.
Trowel Arm Inspection
Trowel arms (Figure 63) can be damaged by rough handling
(i.e. dropping the trowel), or by striking exposed plumbing,
rebar, or other objects during operation. A bent trowel arm
will prevent smooth, fluid rotation of the blades. If bent
trowel arms are suspected, examine them for straightness
as follows.
Figure 63. Trowel Arm
TROWEL
ARM
ROLL PIN
SPIDER PLATE
ZERK
GREASE
FITTING
CAP
BUSHING
TROWEL ARM
ROUND SHAFT
SECTION
ROLL PIN
HOLE
BLADE ATTACHMENT
BOLT HOLE
FLAT OF
HEXAGONAL SHAFT
(TOP OF ARM)
LEVER
MOUNTING
SLOT
TROWEL ARM
HEXAGONAL (HEX)
SHAFT SECTION
1. Place the trowel arm on a thick, steel plate, granite slab,
or any other surface which is
true and flat (Figure 64).
Figure 64. Trowel Arm Inspection
2. Check each of the six sides of the trowel arm hex
section (Figure 64). A feeler gauge of .004 inch
(0.10 mm) should not pass between the test surface
and the flat of the trowel arm at any point along its
length on the test surface.
3. As the flat hex section rests on the test surface, use
a feeler gauge of .005 inch (0.127 mm) to check the
clearance between the round shaft section and the test
surface. Rotate the arm to each of the flat hex sections
and check the clearance between the round shaft and
the test surface. The clearance between the round shaft
and the test surface should be identical for each hex
section. See Figure 64.
4. Replace any bent or uneven trowel arms.
TROWEL ARM
FLAT TEST
SURFACE
HEX SECTION
FEELER GAUGE
.004 IN./0.10 MM
ROUND SECTION
FEELER GAUGE
.005 IN./0.127 MM
