Rover DEFENDER 300Tdi, Workshop Manual

Page: 151 / 450

MANUAL GEARBOX
1 FAULT DIAGNOSIS
R380 GEARBOX
Symptom - Gear jumps out of engagement (any
forward gear)
1. Check condition and security of transmission
and engine mountings.
2. Check in situ, gear lever and selector
adjustments See Adjustment, Gear change
lever bias spring - adjust and See
Adjustment, Fifth gear stop screw adjust .
3. In situ, remove gearshift and check selector rail
yoke security.
Also check selector detent spring tension and
both spool retainers.
Suspect internal fault, see Overhaul Manual.
4. Check action/operation of main selector rail and
forks.
5. Check condition of synchromesh and gear dog
teeth.
6. Check main and layshaft end floats bearings and
adjustments.
7. Check condition of all gearbox components,
ensure clearances and adjustments are correct
on reassembly.
Symptom - Reverse gear only jumps out of
engagment
1. Check condition and security of transmission
and engine mountings.
2. Check in situ, gear lever and selector
adjustments See Adjustment, Gear change
lever bias spring adjust and See Adjustment,
Fifth gear stop screw adjust .
3. In situ, remove gearshift and check selector rail
yoke security.
Also check selector detent spring tension and
both spool retainers.
Suspect internal fault, see Overhaul Manual.
4. Check action/operation of main selector rail and
reverse lever.
5. Check condition of reverse gear, angled
bearings and shaft.
6. Check condition of all gearbox components,
ensure clearances and adjustments are correct
on reassembly.
Symptom - Excessive force required to engage or
change gear, vehicle stationary or moving.
1. Check lubricant specification and level, if low do
not top up at this stage.
2. In situ, lubricate gear mechanism, and check
selector adjustments See Adjustment, Gear
change lever bias spring - adjust and See
Adjustment, Fifth gear stop screw adjust .
3. In situ, remove gearshift and check selector rail
is free and that the yoke is secure. Also check
selector detent spring tension and both spool
retainers.
4. Drain lubricant and check for contamination or
metal particles.
Suspect worn synchromesh unit or baulk rings
on affected gears, see Overhaul Manual.
Symptom - Noisy gear engagement, vehicle
stationary
See CLUTCH, Fault diagnosis, Clutch
Noise - Mechanical Faults .
Symptom - Noisy gear selection, vehicle moving.
1. Confirm that clutch operation is satisfactory.
2. Establish which gear/gears is causing noise.
3. Check lubricant specification and level, if low do
not top up at this stage.
4. Drain lubricant and check for contamination or
metal particles.
Suspect worn synchromesh, see Overhaul
Manual.
5. Check condition of synchromesh unit, springs
and cones for distortion and wear. Also check
dog teeth for damage and cone mating surface
on gear for signs of overheating.
6. Check condition of all gearbox components,
ensure clearances and adjustments are correct
on reassembly.
Symptom - Noise from gearbox in neutral, which
changes tone or becomes worse when clutch is
depressed,
See CLUTCH, Fault diagnosis, Clutch
Noise - Mechanical Faults .
Symptom - Noise from gearbox in neutral, which
disappears when clutch is depressed.
1. Check lubricant specification and level, if low do
not top up at this stage.
2. Drain lubricant and check for contamination or
metal particles.
Suspect worn bearings on layshaft, primary shaft
or front of main shaft, see Overhaul Manual.