MQS36H SeRIeS WaLK-BeHIND TROWeL • OpeRaTION aND paRTS MaNUaL — Rev. #0 (03/08/12) — page 35
Maintenance
CHeCKINg TROWeL aRM STRaIgHTNeSS
Trowel arms (Figure 53) can be damaged by rough
handling, such as dropping the trowel on the pad, or by
striking exposed plumbing, forms, or rebar while in
operation. A bent trowel arm will not allow the trowel to
operate in a smooth fluid rotation. If bent trowel arms are
suspect, check for flatness as follows:
Figure 53. Trowel Arm
1. Use a thick steel plate, granite slab or any surface
which is true and flat, to check all six sides of each
trowel arm for flatness (Figure 54).
2. Check each of the six sides of the trowel arm (hex
section). A feeler gauge of .004 inch (0.10 mm) should
not pass between the flat of the trowel arm and the test
surface along its length on the test surface.
Figure 54. Checking Trowel Arm Flatness
3. Next, check the clearance between the round shaft
and the test surface as one of the flat hex sections of
the arm rests on the test surface. Rotate the arm to
each of the flat hex sections and check the clearance
of the round shaft. Use a feeler gauge (Figure 55) of
.005 inch (0.127 mm). Each section should have the
same clearance between the round of the trowel arm
shaft and the test surface.
4. If the trowel arm is found to be uneven or bent, replace
the trowel arm.
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
TROWEL
ARM
TROWEL
ARM
FLAT TEST
SURFACE
FEELER GAUGE
(.004 IN/0.10 MM)
FEELER GAUGE
(.005 IN/0.127 MM)
TROWeL aRM LeveR aDjUSTMeNT
The easiest and most consistent way to adjust the trowel
arm lever is to use the Trowel Arm Adjustment Fixture
(P.N. 1817).
As each trowel arm is locked into the fixture, the arm bolt
is adjusted to where it contacts a stop on the fixture. This
will consistently adjust all of the trowel arms, keeping the
finisher as flat and evenly pitched as possible.
This fixture will allow consistent adjustment of the trowel
arm lever. It comes with all the hardware necessary to
properly accomplish this maintenance and instructions on
how to properly utilize this tool. Adjusting the trowel arm
lever without a fixture requires a special talent.
Perform the following procedure when adjusting the trowel
arm lever:
1. Unscrew the locking bolts on the adjustment fixture and
place the trowel arm (lever attached) into the fixture
channel as shown in Figure 55.
2. Ensure the fixture arm is in the up position.
3. A thin shim may be required to cover the blade holes
on the trowel arm. Make sure to align the trowel
adjustment bolt with the fixture adjustment bolt.
Figure 55. Trowel Arm Adjustment Fixture
4. Use an allen wrench to tighten the locking bolts
securing the trowel arm in place.
5. Adjust the bolt distance shown in Figure 55 to match
one of the arms. The other arms will be adjusted to
match this distance.
6. Loosen the locking nut on the trowel arm lever, then
turn the trowel arm adjusting bolt until it barely touches
(.010") the fixture adjusting bolt.
ARM
SHIM
LOCKING
BOLTS
TROWEL ARM
ADJUSTMENT FIXTURE
TROWEL
ARM
LEVER
FIXTURE
ARM
DISTANCE
.010 INCH
ADJUSTMENT
BOLT
ADJUSTMENT
BOLT
