Twin Disc MG-5170DC, Service Manual

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Twin Disc, Incorporated
Assembly
Marine Transmission Service Manual #1020667
Output Shaft Tapered Roller Bearing Adjustment
1. To set output shaft bearing clearance, proceed as follows.
A. Install seal carrier without seals or O-ring. Secure seal carrier
with capscrews using very little torque on capscrews. Use a taper
gauge or feeler gauge to measure gap between rear housing
face and flange of output seal carrier. Build a trial shim pack of
thickness equal to gap plus 0.50 mm (0.020 in.). Install the shim
pack.
B. To lift output shaft, install eyebolts and strap to rear of output shaft.
Apply 1340 N to 4000 N (300 lbs to 900 lbs) of downward force
on rear end of output shaft. Seat front bearing rollers by rotating
shaft several revolutions with weight applied.
C. Install dial indicator onto the housing with finger resting on rear of
output shaft or on lifting fixtures. Zero the dial indicator and mark
the spot where the reading was taken.
D. Using a hoist, exert 2225 N to 4000 N (500 lbs to 900 lbs) of
lifting force onto the shaft. Minimum of 2224 N (500 lbs) lifting
force is required to overcome weight of gear and shaft and still
exert a minimum of 1334 N (300 lbs) lifting force on bearing.
Rotate shaft several revolutions with lifting force applied. Stop
rotation with dial indicator finger on mark previously made,
continuing to hold lifting force. Read shaft endplay on dial indicator.
E. Make a shim pack to decrease endplay to 0.05 mm to 0.15 mm
(0.002 in. to 0.006 in.). Arrange the shims so the clearance holes
for the pusher screws are aligned. Install shim pack between
seal carrier and housing.
F. Repeat steps B through D until endplay is between 0.05 mm to
0.15 mm (0.002 in. to 0.006 in.).
2. Remove lifting fixture. Remove capscrews and remove output seal
carrier.