Page 23
ROYAL ENFIELD 350cc and 500cc O.H.V. WORKSHOP MANUAL
CHAINS
.
34. Lubrication.
The front chain is lubricated by filling the oilbath
case with engine oil up to the level of the overflow
plug.
The rear chain should be lubricated regularly by
the driver, but if it is dry or dirty must be removed,
thoroughly washed in paraffin and soaked in engine
oil or preferably in melted grease to which a little
graphite has been added.
35. Tensioning.
The front chain should have approximately ¼ in.
free movement up and down ; the rear chain about ½
in. If the tension varies in different parts of the chain,
adjust to the above figures at the tightest point.
To adjust the front chain, loosen the nuts on the
studs which hold the gearbox to the engine plates,
unscrew the central push bolt between the plates and
lever the gearbox backwards until the tension is
correct. This can be gauged through the inspection
hole in the chaincase. After the chain has been
correctly tensioned, securely tighten up the nuts on the
gearbox attachment studs and screw up the central
push bolt, until it bears hard against the upper lug on
the gearbox, and tighten the locknut. The purpose of
this push bolt is to prevent the gearbox moving
backwards owing to the pull of the rear chain, which is
greater than that of the front one.
To tension the rear chain, loosen the wheel
spindle nuts and adjust by means of the adjuster
screws in each fork end. Take care to turn each
adjuster equally, otherwise the wheel will be thrown
out of alignment.
36.
Limits of Wear.
A chain is considered to be worn out when its
length under load is 2 per cent. longer than the length
of a new chain of the same type and same number of
links. For the primary chain this means an increase in
length of 3/4 in. and for the final drive chain of 1.1/8
in. When measuring chains for wear, the load applied
should be 28 lbs. for the ½ in. pitch primary chain
and 42-44 lbs. for the 5/8 in. pitch final drive chain.
37. Removal, Repair and Replacement.
Both chains are fitted with spring links to
facilitate removal. The springs can be removed with
the fingers or with the aid of a pair of pliers.
If it is required to replace any of the links in a
chain (as, for example, in the unlikely event of a roller
or rollers having broken), two adjacent rivets passing
through the same outer plate must be removed. To do
this, use a rivet extractor or support the chain on two
small nuts (1/4 in. or 3/16 in. diameter) and drive the
rivets out with a small punch. When replacing rivetted
links, support the under side of the chain on a flat
piece of steel and drive the outer plate over the rivets
by means of a hollow punch (or small nut) applied
over each rivet in turn. Hammer the ends of the rivets
over lightly, taking care not to distort the outer plate
so as to cause a tight joint.
Never join together new
and badly worn lengths of chain.
When replacing the chains make sure that the
open ends of the spring connecting links point away
from the direction of travel. The back half of the
connecting link is easily inserted in the rear chain if
the ends of the chain are brought together on the rear
sprocket. In the case of the front chain, however, the
connecting link must be inserted in the straight run of
the chain as there is insufficient clearance behind the
sprockets to allow the link to be inserted. It will be
found that the link can be inserted much more readily
if the ends of the chain are pulled together by a pair of
round-nosed pliers or similar tool, or by a loop of fine
string.
www.hitchcocksmotorcycles.com
