Checking Connecting Rod Bolt Stretch - Triumph SPEED TWIN 1945 Workshop Instruction Manual

Connectine Rod
insert t h e nev:. Ensure that t h e oilw-j.; are aligned. W h e n reamering t h e bush.
care must be taken t o ensure that t h e b o r e is parallel w i t h t h e big-end.
The final examination
i s
the fit of t h e main bearings o n t h e crank t i m i n g and driving
shafts. The bearings should be a t i g h t push
fit
; a loose fitting bearing would tend
t o cause crankcase "rumble".
Assembly. Place the b o t t o m end of t h e flywheel i n the vice and position the timing
and driving side cranks t o t h e i r respecrive sides. Fit six NEW bolts and nuts (the
o l d parts should never be re-used), and fully tighten. Lock the nuts by centre
punching t h e periphery of t h e thread. Oil t h e journal bearings and t i t the respective
connecting rods. Before doing this, measure t h e overall length o f t h e connecting
r o d b o l t w i t h a micrometer; during the tightening process the b o l t w i l l be stretched.
Again the micrometer should be employed and when the bolt has stretched ,007"
(0.178 mm.)-.008" (0.203 mm.) it is then under correct tension and must not be
furrher tightened. Apply t h e nozzle o f an oil gun t o the timing shalt oilway and
pump oil through the crankshaft u n t i l
it
passes the connecting r o d bearings.
T
BOLT
LENGTH
PLUS
.008"
(.2032
m/rn
)
I
Fig. 17.
C H E C K I N G C O N N E C T I N G R O D B O L T STRETCH