6. MEASURING CASTOR ANGLE & K.P.I.
6.0
USE OF GA44 STEERING TURNTABLES. It is recommended that the gauge be used in
conjunction with a pair of GA44 steering turntables to improve accuracy. The vehicles front
wheels should be positioned centrally on the turntables as described in the instructions for the
GA44. Front wheel drive vehicles should have the foot brake applied by means of a brake
pedal depressor or similar means to prevent the front wheels rotating whilst using the gauge.
Before taking any readings the locking pins should be removed from the turntables.
6.1
MOUNTING THE GAUGE. There are three alternative ways of mounting the castor angle and
king pin inclination gauge to a wheel. The most common method will be to use one of the the
wheel stud brackets as shown in fig.5. Each wheel stud bracket is provided with a matching
conical washer which may be needed to accommodate reduced diameter studs. The centre
lock bracket shown in fig.6 is for use with centre lock wheels where the two hooks will either be
attached to spokes on the wheel or hooked around the back of the centre lock nut. The stud
axle clamp shown in fig.7 allows the gauge to be attached to a central hub nut. When the
appropriate clamp is in position slide the gauge onto the spindle and secure it with the knurled
nut in an approximate horizontal position. The castor dial should be on the left as shown in fig.5.
6.2
CHECK THAT THE FLOOR IS LEVEL. See section 7.0. Also check tyre inflation levels.
6.2
TAKING READINGS. Turn the front of the wheel to be checked IN by 20
O
(i.e. the right hand
wheel turned to the left or the left hand wheel turned to the right.) Turn both dials on the gauge
until zero is in line with the index pointer then centre the bubbles on both spirit levels by turning
the knurled screws below each dial.
6.3
Next steer the front of the wheel being checked OUT by 20
O
.
6.4
Centre the bubbles in both spirit levels by turning the CASTOR dial and KPI dial respectively
making a note of the number of graduations through which each dial rotates.
6.5
The scales on both dials are additive. If the king pin inclination dial is rotated a full revolution
and the spirit level bubble is still not centred continue to turn the dial until it is centred.The king
pin inclination angle is therefore the sum of the total number of graduations that the dial has
been turned through. The same applies to the castor angle dial readings which are additive
after the dial has been turned through half a revolution.
fig.5
fig.6
fig.7
fig.8
fig.9
7.1
Check that the floor is level using the camber gauge as follows. Turn the dial marked degrees (see fig.2 - A) so that 0 is in line
with the index pointer. Place the gauge on the floor at right angles to the wheel to be checked. (Check floor level along the vehicles
length when measuring castor angle). If the bubble in the spirit level is not centred then the floor is not level. Turn the dial in either
direction until the bubble is centred. The slope of the floor in degrees is represented by the number of graduations turned through on the dial.
7.2
ADJUSTING READINGS WHEN THE FLOOR IS NOT LEVEL. Readings can still be taken on a sloping surface up to 3
O
maximum.
Establish the angle of the slope using the camber gauge as described above. Note the direction of the slope and the vehicles
orientation on it. To make a correction, the slope angle should either be added to, or subtracted from your reading according to the
chart below. Where the chart indicates N/A this means that no adjustment is necessary in that particular orientation.
01284 757500
E-mail:
01284 703534
Sole UK Distributor,
Sealey Group,
Bury St. Edmunds,
Suffolk.
NOTE:
It is our policy to continually improve products and as such we reserve the right to alter data, specifications and component parts without prior notice.
IMPORTANT:
No liability is accepted for incorrect use of this product.
WARRANTY:
Guarantee is 12 months from purchase date, proof of which will be required
for any claim.
INFORMATION:
Call us for a copy of our latest catalogue on 01284 757525 and leave your full name and address including your postcode.
SLOPING FLOOR
SLOPING SIDE TO SIDE
SLOPING LENGHTWISE
COMPENSATION
CHART
NEARSIDE (HIGH)
OFFSIDE
NEARSIDE
OFFSIDE (HIGH)
REAR
FRONT (HIGH)
REAR (HIGH)
FRONT
SLOPE ANGLE
ORIENTATION
CAMBER ANGLE
ADD X
O
SUBTRACT X
O
SUBTRACT X
O
ADD X
O
N/A
N/A
KING PIN Inclination SUBTRACT X
O
ADD X
O
ADD X
O
SUBTRACT X
O
N/A
N/A
Subtract Y
O
from + readings
Add Y
O
to + readings
CASTOR ANGLE
N/A
N/A
N/A
N/A
Add Y
O
to - readings
Subtract Y
O
from - readings
GA44 - (1) - 030502
7. CHECKING THE FLOOR LEVEL
