Service Instructions For Steer Axle; Steering Knuckle Kingpin Inspection; Checking Lateral Slackness; Checking Vertical Slackness - PREVOST H3-41 Maintenance Manual

SECTION 10: FRONT I-BEAM AXLE
6. SERVICE INSTRUCTIONS FOR STEER
AXLE
MAINTENANCE
An inspection should be made at the intervals
specified by the Lubrication And Servicing
Schedule in Section 24: LUBRICATION &
SERVICING.
6.1 STEERING KNUCKLE KINGPIN
INSPECTION
Check permissible slackness in the kingpins as
follows:
Aspects to be considered are:
Lateral slackness
•
Vertical slackness
•
NOTE
Before commencing checks, apply parking
brake, raise wheels off ground and support axle
on stands.
6.1.1

Checking Lateral Slackness

Following regular and
practices will maximise bushing life. This
procedure measures the upper bearing & lower
bushing wear due to side and vertical loading.
While this is being carried out, the brake must be
applied.
1. Place a set-square with its stock on ground
and its blade against tire wall.
2. Place a mark on the ground to indicate
position of stock end.
3. Insert a lever through bottom cut-out of
wheel and lever it upwards thus moving set-
square outboard.
4. Mark the changed position of the stock end.
5. Maximum allowable stock displacement (for
22.5" wheels) is 0.315 in (8mm).
6. If displacement exceeds stated allowance
then need for bushing / bearing attention and
possible renewal, is in evidence.
10
PA1621 Maintenance Manual All Series
thorough greasing
|
Section revised October 2018
NOTE
To avoid inaccurate measurements, be careful
not to let the knuckle turn while moving
assembly in and out. Applying brakes will help
lock wheel assembly.
6.1.2

Checking Vertical Slackness

1. This is measured by a dial indicator
anchored to axle beam and having its
pointer placed vertical against knuckle top.
2. Place a jack against underside of knuckle
and, while applying a lifting force, observe
any movement on indicator dial.
3. If vertical movement is evident and it
exceeds 0.030"
readjustment of knuckle is required by
adjusting thickness of bearing adjusting
shims. In this case, refer to:
Dana Parts & Service Instructions S84U Steer
Axle KING PIN REWORK_ Manual NO 1985 B
iss A.
6.2

STEERING TIE ROD INSPECTION

FIGURE 3
The steering tie rod on the axle requires several
visual and functional inspections. Refer to
Section 14– STEERING under heading FRONT
I-BEAM AXLE TIE ROD.
Detailed information can also be found in the
following supplier publication:
TRW_Front_Axle_Steering_Bar_Service_Info
rmation_XSZ143
7.

FRONT WHEEL ALIGNMENT

Refer to Section 14: STEERING.
(0.76mm) then