Hewland NMT, Servicing Instructions

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PAGE 5
© Copyright Hewland Engineering Limited
GENERAL NOTES :-
a/
Read these instructions carefully and with reference to the illustrations.
b/
Before dismantling the gearbox, see that a clean tray is available, in which to place the parts.
c/
Thoroughly clean and inspect all parts before reassembly. Discard any worn or damaged components and replace with new
ones.
d/
Use only genuine Hewland parts as replacements. These are manufactured in our workshops to the fine tolerances necessary and
are rigorously inspected.
e/
Always ensure that locknuts, and oil seals are in good condition when reassembling.
f/
All studs and screws must be Loctited or wirelocked in position, unless stated otherwise
g/
Bearing Replacement :-
Bearings can only be removed or renewed if the casings have been warmed in an oven, or with a blowlamp. In the latter case,
keep the blowlamp moving while heating the casing.
Note: Do not overheat. Test with a spot of water which will bounce off at the correct temperature.
Once a casing is heated, all bearings should be pressed into their respective seatings without delay, thus eliminating the need to
reheat. At the correct temperature, fitting the bearings should present no difficulty.
During cooling, or when the casings have cooled, it is advisable to once more lightly press the bearings to ensure that they are
correctly seated.
h/ Oil:
Fill the gearbox through the plug hole on top of the maincase. The oil will find it's own level within the gearbox.
Note: Too much oil will not directly cause any harm, but is undesirable as it may induce power loss and overheating of internals.