Disassemble Steering Knuckle Assembly
Start By:
a. remove axle shaft and universal joint assembly
1. Disconnect the steering cylinder from the steering arm.
2. Disconnect the tie rod ends at clevis joint.
3. Remove the dust shield.
4. Remove hydraulic brake line from the wheel cylinder inlet fitting and cap or plug the openings.
5. Remove the bolts from the king pin caps.
NOTE: Do not mix the upper and lower shim packs.
6. Remove the lower king pin cap (3), shims (1) and thrust washer (2) first. Then remove the upper king pin cap and shims (upper cap does not use a thrust washer). Keep each shim pack together and correctly identified for reassembly.
7. Loosen the outer boot clamp wire and fold the boot (4) back onto the axle housing.
8. Remove the steering knuckle (5) from the axle housing trunnion socket. The knuckle can be tipped to clear the socket.
9. Drive out each expansion plug and king pin bronze bushing from the axle housing trunnion socket.
Assemble Steering Knuckle Assembly
1. Install new king pin bushings (1) flush with the outside surface of each trunnion socket king pin boss (2) using a suitable driver.
2. Check the fit of the knuckle pin caps in the new bushings and, if necessary, ream the bushings to the correct size.
3. Install the expansion plugs (3) at the inside end of each trunnion socket king pin bore.
4. Lubricate king pin bushing bores with grease.
5. Install steering knuckle (4) over the axle housing trunnion socket.
6. Install upper king pin cap (5) with original shim pack. It may be necessary to force the cap into the knuckle bushings by tightening the king pin bolts alternately in small increments, keeping the king pin cap straight with respect to the knuckle bushing bore.
NOTE: Apply grease to the grooved face of the thrust washer prior to installation on the lower king pin cap.
7. Install lower king pin cap (7) with original shim pack (6). The tangs of the thrust washer must face the trunnion socket. It may be necessary to force the lower cap into the knuckle bushings by tightening the king pin bolts alternately in small increments, keeping the king pin cap straight with respect to the knuckle bushing bore.
| NOTICE |
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Make sure that the thrust washer tangs engage the slots in the trunnion socket boss before final tightening of the lower king pin cap bolts. |
8. Tighten the bolts to their specified torque.
NOTE: The steering knuckle must be adjusted at this time. Use the adjustment procedure that follows:
Steering Knuckle Adjustment Procedure
Steering knuckle adjustment is accomplished by use of shims (1) located between the upper and lower king pin cap mounting flanges and steering knuckle. The correct amount of knuckle vertical end play is 0.13 to 0.33 mm (.005 to .013 in).
A. Vertical end play of the steering knuckle can be measured either by using a feeler gauge to measure the gap (2) between the upper king pin cap shoulder and top surface of the trunnion socket king pin boss, or by checking actual maximum vertical movement of the knuckle with a dial indicator.
Feeler gauge measurement:
(a) If wheels are on the ground supporting the weight of the machine, measurement of the gap can be made directly. Record the measurement.
(b) If axle is supported on blocks, the knuckle will have to be forced upward to its maximum movement with a jack or prybar before the gap measurement is made. Record the measurement.
Dial indicator measurement:
(a) If wheels are on the ground supporting the weight of machine, zero the dial indicator and jack up the axle until wheel is off the ground. Record the dial indicator reading of the vertical movement.
(b) If axle is supported on blocks, zero the dial indicator and then force the knuckle upward to its maximum movement with a jack or prybar. Record the dial indicator reading of the vertical movement.
B. If the end play is less than 0.33 mm (.013 in), no adjustment is necessary.
C. If the end play exceeds 0.33 mm (.013 in), continue the following steps.
D. Remove lower and upper king pin caps and measure the total current shim pack thickness (upper pack plus lower pack).
E. Subtract actual end play (value from step A) from the total shim pack thickness (value from step D) and divide this result by two.
Example:
(a) Current end play measurement: 0.51 mm (.020 in)
(b) Conclude adjustment is necessary.
(c) Current total shim pack thickness: 1.68 mm (.066 in)
(d) 1.68 - 0.51 mm (.066 - .020 in) = 1.17mm (.046 in)
1.17 mm (.046 in) divided by 2 = 0.58 mm (.023 in)
(e) New lower pack: 0.58 mm (.023 in)
(f) New upper pack:
0.58 + 0.13 mm (.023 + .005 in) = 0.71 mm (.028 in)
F. Make the new lower shim pack thickness the same as value from the example (d) calculation. If this thickness cannot be met exactly, choose the nearest thicker shim.
G. Make the new upper shim pack thickness the same as value from the example (d) calculation plus 0.13 mm (.005 in). If this result cannot be met exactly, choose the nearest thicker shim.
9. Slip the boot back onto the steering knuckle and fasten the outer boot clamp wire.
10. Install brake line to wheel cylinder inlet fitting.
11. Attach steering cylinder to knuckle arm.
12. Attach tie rod to steering knuckle, and tighten bolt and nut to a torque of 0 to 7 Nm (0 to 5 lb ft). Install the cotter pin.
13. Install brake dust shields.
End By:
a. install axle shaft and universal joint assembly