Hewland NMT, Servicing Instructions

Page: 10 / 40

PAGE 10
© Copyright Hewland Engineering Limited
FIGURE 5
SEQUENTIAL BARREL SETTING - Requires special tool No.SK-1451
a/
Assemble the barrel (15), spacer (26), bearing retaining plate (25),
bearing (27), and nut (29). Heat the bearing carrier (2), slide the barrel
assembly into the bearing carrier, and secure using screws (12).
b/
Place the roller (24) onto the detent plunger (21), and insert them into
the bearing carrier (2). Add the detent spring (22), bonded seal (115),
and detent plug (23).
c/
Slide the selector forks (17) over the barrel (15), and secure using
selector pins (18). For final assembly, Loctite the pins (18) into the forks
(17).
d/
Stack the pinion gears (16), hubs (19,20), clutch rings (19) and spacer
(14) in place in the bearing carrier, and slide the whole thing onto the
dummy shaft of fixture SK-1451.
e/
Tighten the pinion shaft nut (111) onto the end of the dummy shaft,
ensuring that the disc spring on the fixture preloads the bearings.
f/
Rotate the barrel to engage first gear. Measure and record the gap
between the dogfaces of third through sixth gears. Engage third gear and
repeat the measurement for first and second dogfaces. It is important
that these dimensions are not taken when the barrel is in the neutral
position.
First, third and fifth gear dog gap measurements will be similar (as will
second, fourth and sixth). Any difference between the odd & even gear
measurements must be corrected by replacing the barrel spacer (26) with
one of the correct thickness.
Note: It is not possible (or necessary) to individually adjust each fork.