Boom Shimming Procedure - JLG 400S Service And Maintenance Manual

SECTION 4 - BOOM & PLATFORM

4.8 BOOM SHIMMING PROCEDURE

NOTE: When installing wear pads, the wear pad bolt lengths may
need to be adjusted as shim thicknesses are adjusted. Bolt
lengths should be flush or up to one thread below the sur-
face of the insert.
1. Measure and take note of the inside width and inside
height of the base boom opening for reference later in
this procedure.
2. Install the side wear pads on the fly boom and shim as
required to match the corresponding dimension
recorded in Step 1 within +0/-1.2 mm. Shims should be
divided as evenly as possible between the sides of the
boom. The number of shims installed at position #1
must match with position #2, and position #3 must
match position #4 as shown below. Take note to how
many shims are installed in each position.
Figure 4-15. Fly Boom Wear Pads
3. Install the top wear pads and shims on the fly boom.
4. Install the bottom wear pads on the fly boom and shim
as required to obtain the total base boom dimension
within +0/-1.2 mm of the corresponding dimension
from Step 1.
5. Slide the fly boom into the base boom, leaving 1 to 2
meters exposed.
6. Install the bottom wear pads and shims into the end of
the base boom.
7. Install the side pads and shims into the base boom. Dis-
tribute shims to each side to match the distribution
noted in Step 2. Positions #5/6 must match positions #1/
4-34
2. Positions #7/8 must match positions #3/4. Verify that
no more shims will fit on either side.
Figure 4-16. Base Boom Wear Pads
NOTE: Do not use a wedge to install more shims than will fit with
the use of a pry bar. This may result in the boom being
shimmed too tight. The use of pry bars should only be used
to finish installing a shim that can be installed by hand
more than half of its length.
8. Install the top wear pads and shims into the base boom
leaving a gap of 0 mm to 1.2 mm between the top of the
fly boom and the inside of the base boom.
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