REF•14 Fault finding
7 Driveshafts
Clicking or knocking noise on turns (at slow speed
on full-lock)
mm Lack of constant velocity joint lubricant, possibly due to damaged
gaiters (Chapter 8).
mm Worn outer constant velocity joint (Chapter 8).
Vibration when accelerating or decelerating
mm Worn inner constant velocity joint (Chapter 8).
mm Bent or distorted driveshaft (Chapter 8).
6 Automatic transmission
Note: Due to the complexity of the automatic transmission, it is difficult
for the home mechanic to properly diagnose and service this unit. For
problems other than the following, the vehicle should be taken to a
dealer service department or automatic transmission specialist. Do not
be too hasty in removing the transmission if a fault is suspected, as
most of the testing is carried out with the unit still fitted.
Fluid leakage
mm To determine the source of a leak, first remove all built-up dirt and
grime from the transmission housing and surrounding areas using
a degreasing agent, or by steam-cleaning. Drive the vehicle at low
speed, so airflow will not blow the leak far from its source. Raise
and support the vehicle, and determine where the leak is coming
from. The following are common areas of leakage:
a) Leaking differential output (driveshaft) oil seal (Chapter 7B).
b) Leaking housing joint (Chapter 2B or 7B).
c) Leaking selector transverse rod oil seal (Chapter 7B).
General gear selection problems
mm Chapter 7B deals with checking and adjusting the selector cable
on automatic transmissions. The following are common problems
which may be caused by a poorly-adjusted cable:
a) Engine starting in gears other than Neutral.
b) Indicator panel indicating a gear other than the one actually being
used.
c) Vehicle moves when in Park or Neutral.
d) Poor gear shift quality or erratic gear changes.
Transmission will not downshift (kickdown) with
accelerator pedal fully depressed
mm Low engine/transmission oil level (Chapter 1).
mm Incorrect selector cable adjustment (Chapter 7B).
Engine will not start in any gear, or starts in gears
other than Neutral
mm Incorrect starter/inhibitor switch adjustment (Chapter 7B).
mm Incorrect selector cable adjustment (Chapter 7B).
Transmission slips, shifts roughly, is noisy, or has
no drive in forward or reverse gears
mm There are many probable causes for the above problems, which
can really only be accurately diagnosed using pressure gauges in
conjunction with a step-by step diagnostic procedure. Problems
of this nature must, therefore, be referred to a dealer or automatic
transmission specialist.
5 Manual transmission
Noisy in neutral with engine running
mm Transfer gear bearings worn (noise apparent with clutch pedal
released, but not when depressed) (Chapter 7A).*
mm Clutch release bearing worn (noise apparent with clutch pedal
depressed, possibly less when released) (Chapter 6).
Noisy in one particular gear
mm Worn, damaged or chipped gear teeth (Chapter 7A).*
Difficulty engaging gears
mm Clutch fault (Chapter 6).
mm Worn or damaged gear linkage (Chapter 7A).
mm Worn synchroniser units (Chapter 7A).*
Jumps out of gear
mm Worn or damaged gear linkage (Chapter 7A).
mm Incorrectly-adjusted gear linkage (Chapter 7A).
mm Worn synchroniser units (Chapter 7A).*
mm Worn selector forks (Chapter 7A).*
Vibration
mm Lack of oil (Chapter 1).
mm Worn bearings (Chapter 7A).*
Lubricant leaks
mm Leaking differential output (driveshaft) oil seal (Chapter 7A).
mm Leaking housing joint (Chapter 2B or 7A).*
*Although the corrective action necessary to remedy the symptoms
described is beyond the scope of the home mechanic, the above
information should be helpful in isolating the cause of the condition, so
that the owner can communicate clearly with a professional mechanic.
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