Technical

VT COMMODORE BRAKE SHUDDER

There has been some concern regarding brake shudder on VT Commodores.
Some of the problems could be associated with the front hubs.
The front hubs need to be checked for end float.
The following procedure should be practiced, as stated in the manual.
1. After removing wheel, temporarily reinstall three, reversed wheel nuts
with a flat washer under each to prevent damage to the nut thread.
2. Mount a dial indicator to a suitable magnetic stand and attach to the front
strut tube.
Position the dial indicator pointer at the outer diameter of the disc, as shown
in drawing.
3. Apply an outward, 10kg (22lb) force to the outer brake disc diameter, in
an opposite direction to the dial indicator. To maintain consistency a spring
balance capable of measuring this force, must be used. With this force
applied zero the dial indicator.
4. Apply an inward, 10kg (22lb) force to the outer brake disc diameter and
note the dial indicator reading.
5. The reading obtained is the angular movement, (not end float); to
determine the bearing’s serviceability, compare the measured result with the
following specifications.

WHEEL BEARING ANGULAR FLOAT SPECIFICATION
          NEW BEARING 0.106mm (0.0042”) MAXIMUM
        USED BEARING 0.213 mm (0.0085”) MAXIMUM

6. Should the inspection show that the wheel bearing assembly is outside the
specified, angular float dimension, and then the hub must be replaced.
          WORN HUBS, CAUSE ROTOR RUN OUT, RESULTING IN DTV
Special care should be taken when machining these discs. Minimum run out
should be achieved.
After machining discs, index the rotors to the hub, to achieve minimum run
out.
          MAXIMUM LATERAL RUN OUT (front discs) .040mm
When tightening wheel nuts the torque specification is 100 – 125 Nm
Avoid over tightening with rattle guns.