Cleaning and Inspection-continued -706880893

TM 5-4210-233-14&P-1

5-39. STEERING GEAR-Continued

(3) Inspect the rack piston (46) teeth for cracks and wear. If you can detect a step by running your

fingernail horizontally across the teeth surface, you must replace both the rack piston and sector

shaft (2) and use a set of 34 service balls (52).

(4) Inspect the rack piston internal ball-track grooves for brinelling (dents) or spalling (flaking). If either

condition exists, you must replace all of the following parts: the rack piston (46), the worm

shaft/input shaft assembly (1), the valve sleeve (37) and the set of 34 balls (52).

(5) Inspect the worm shaft/input shaft assembly (1) ball track grooves for brinelling (denting) or

spalling (flaking). If either condition exists, you must replace all of the following parts; the worm

shaft/input shaft assembly (1), the rack piston (46), the valve sleeve (37), and the set of 34 balls.

Visually inspect the upper shaft seal area near the input shaft serrations for nicks, and run your

fingernail edge across the sealing surface to detect steps. Visually inspect the sleeve (37) contact

area of the worm shaft/input shaft for discoloration from excess heat. If either of these conditions

exist you must replace the worm shaft/input shaft assembly (1) and valve sleeve (37) as a matched

set.

NOTE

The input shaft is pinned to the worm shaft by the torsion bar

pin, and the assembly is flexible and may appear slightly bent at

this joint. This slight bend is normal.

(6) Inspect the housing (18) cylinder bore. You will probably notice normal scoring marks running

lengthwise through the bore. Since this scoring is normal, you should not compare it to the scoring

considered detrimental in the cylinder bores of an internal combustion engine.

NOTE

In running the internal leakage test after reassembly of the unit,

make sure that internal leakage exceeding 1.0 gpm (3.8

liters/min.) can only be attributed to the housing and not to the

improper assembly of the new seals in the worm shaft, rack

piston, and valve assembly, before you decide to replace the

housing.

(7) Inspect the housing (1 8) for nicks that would prevent proper sealing. Replace the gear housing if

these nicks are present and cannot be easily removed with a fine-toothed flat file without changing

the dimensional characteristics.

WARNING

For bearing type with uncaged (loose) rolls do not mix the rolls

from the side cover bearing with the rolls from the housing

bearing. The bearing race and rollers are a matched set,

interchanging the rolls could result in premature bearing or seal

failure, which could cause a loss of power steering.

(8) Inspect the housing bearing and the side cover bearing race and rolls for brinelling or spalling. If

either condition exists, replace the damaged housing bearing (16). For the housing bearing, follow

disassembly step (40) and assembly step (2). If the side cover bearing is damaged, replace side

cover assembly.

5-223