STG global TANVAC HDV3000, Operator'S Manual

Page: 248 / 329

SB--7--622 Page 15
SECTION 6
DISASSEMBLY INSTRUCTIONS
Numbers in parentheses ( ) refer to
key numbers in assembly drawings
on pages 25, 27 and 29.
1. Drain oil from gear case by removing drain plug
(4).
2. Remove the socket head bolts (5) from the gear
cover (3).
3. Remove the gear cover from gear headplate (18).
The cover and gear headplate gasket
tends to bond tightly to both sur-
faces. After socket head bolt remov-
al, it is sometimes necessary to take
a ball peen hammer and a blunt chisel
and drive off the cover.
IMPORTANT:
MARK ALL PARTS WITH A CENTER PUNCH SO
THEY CAN BE REASSEMBLED IN THE SAME POSI-
TION (IMPELLERS, HEADPLATES, AND GEARS).
4. If the timing gears appear undamaged, the gear
backlash must be checked to see if the gears can
be salvaged.
A. Mount a magnetic base dial indicator on the
gear headplate (see FIGURE 12).
B. Lock one impeller stationary by wedging a
feeler gage between the impeller and the
headplate.
C. The tip of the indicator should be placed at
the center of the contact surface on a tooth
of the gear on the free shaft.
D. Rock the impeller back and forth by hand and
read the total rotational movement to the
nearest .0005 inches. Do this at four gear
mesh positions 90 degrees apart.
E. Permissible gear backlash is shown below.
GEAR DIA. GEAR BACKLASH
6” .002 -- .003
7” .003 -- .005
8” .003 -- .006
FIGURE 12 FIGURE 13