Lister Petter TR1, Workshop Manual

Page: 48 / 121

page 48
Section 02
Engine Servicing and Adjustments
- camshaft
02.36 THE CAMSHAFT
The steel camshaft is carried in plain bearings in
the crankcase at both the flywheel end and in the centre
web(s). A ball bearing attached to the camshaft and
fitted behind the camshaft gear provides the bearing
for the gear end. The camshaft gear carries the
governor weights.
Cams on the camshaft operate the valve tappets,
oil pump, fuel pumps and the fuel lift pump.
Removing the Camshaft
1. Remove the sump.
2. Remove the oil pump.
3. Remove the end cover.
4. Remove the governor and fuel pumps.
5. If the engine is in its normal plane hold the cam
followers clear of the camshaft using suitable clips
or magnets.
6. Gently ease the camshaft out of the crankcase
keeping it square at all times.
7. Remove the cam followers.
Inspecting the Camshaft
a. Examine the camshaft bush for scars or wear.
b. Examine the ball race bearing for wear and freedom
of movement.
c. Check the camshaft gearwheel and crankshaft
pinion teeth for wear.
d. Ensure the cams are not damaged.
e. Check the tappets for scars or damage to the
contact face.
f. Examine the oil seal in the end cover for damage
or wear.
Replacing the Camshaft
1. Replace the cam followers and secure them in their
highest positions.
2. Carefully replace the camshaft into the crankcase
keeping it square at all times; take care to line up
the '0' timing marks on the crankshaft and camshaft
gears exactly.
Figure 2.36.1 Gear Timing Marks
3. Release the cam followers.
4. Replace the oil pump, sump, fuel pumps, governor
and end cover.
Camshaft Endfloat
The end float, maintained with a single metal shim
between the camshaft thrust washer and the camshaft
gearwheel hub, is 0.08-0.2mm (0.003-0.008in).
In engines where the camshaft does not extend
through the end cover the end float can be measured
through the top right hand tapped hole of the gear cover
SAE flange.
Figure 2.36.2 Camshaft End Float Access
1. Remove the setscrew (A) from the end cover.
2. Use a suitable rod through the hole to push the
camshaft gearwheel as far as it will-go towards the
flywheel end.
3. Insert a clock gauge extension through the hole
until it rests against the gearwheel and zero the
gauge.
4. Push the camshaft gearwheel towards the gear end
by inserting a suitably cranked rod through the fuel
pump inspection door and check the gauge reading.
This endfloat should be 0.08-0.2mm (0.003-0.008in).
CAUTION
Excessive cam shaft end float affects the governing and
can cause uneven firing. Some early engines were fitted
with a paper gear end cover joint and if this is replaced
with a new type thicker joint the end float must be checked
and adjusted as necessary.