Power Assisted Steering Box (TRW)

Power steering gear, disassembling and reassembling (TRW)

This repair is limited to replacing the sealing rings and, if necessary, the toothed rod. Steering gears that are damaged by an accident must be replaced.
For a satisfactory and successful repair, the greatest care, safety and proper tools are required. The special tool set 3315 that is pictured is also a part of this.

NOTE:
Clean hose connections and thoroughly before opening their surroundings
Thoroughly clean work place (workbench, vise) before starting work if necessary place paper towels on the working surface
Place parts that have been removed on a clean surface. If the repair will not be carried out immediately, cover parts
Do not use cloths with lint
All the replacement parts that are needed are contained in the repair kit
Only take replacement parts out of the package right before installing. Use only parts in original packaging
Always install all of the parts in the repair kit






Tie rods, removed. Service and Repair
Close hose connections on power steering gear if not already done
1 Plastic locking screw
2 Plastic locking screw

Clean outside of power steering gear
Open hose clamp and push back boot






Clamp steering gear with toothed rod in vise and remove tie rod

NOTE: Use jaw covers and check jaw covers for contamination; e.g. metal chips or the like

Remove tie rod
Take steering gear out of vise, screw on bracket tool No. 3315/1, or equivalent, and tighten bracket in vise






Mark position of adjusting screw and lock nut to the housing (arrow)
Screw lock nut together with adjusting screw






NOTE: Do not change position of adjusting screw to lock nut when removing. If necessary, remove adjusting screw together with lock nut using tool No. 3115/6, or equivalent. Pressure piece/adjusting screw are slightly stressed with slight spring pressure

1 Ratchet (standard commercial)
2 Adjusting screw






Mark installation position of pressure piece and remove
1 Spreading pliers (standard commercial)
2 Pressure piece






Remove circlip for valve body
1 Needle nose pliers (standard commercial)






Remove lower locking screw for valve body
1 Ratchet (standard commercial)

NOTE: If very tightly seated, loosen locking screw with a hammer and driver






Remove hex nut below valve body
1 Ratchet (standard commercial)
2 Open-end wrench (standard commercial)

Drive valve body upward from below with driver
Remove grease from teeth of valve body
Pull adhesive tape out of the housing
Pull toothed rod all the way to the left






Turn lock washer so that the opening of the circlip (arrow) is in the groove of the housing
Continue to turn the lock washer (direction of rotation left or right) so that the circlip turns out of the housing

Pull toothed rod with toothed rod guide out of the housing. Pull off toothed rod guide and place toothed rod so that toothed rod piston sealing ring will not be damaged
1 Needle nose pliers (standard commercial)

Lubricate toothed rod






Drive valve body sealing ring upward
A Puller, e.g. Kukko tool No. 21/4, or equivalent
B Driver

When installing the puller -A- make sure that the claws engage properly under the sealing ring. The puller must not be spread too wide because otherwise the seat for the sealing ring and housing will be damaged or the sealing ring can jam in the housing.






For easier installation of the puller, it is recommended that a rubber band be placed around the claws. Illustration shows the housing in cross section for better view
1 Puller, e.g. Kukko tool No. 21/4, or equivalent,
2 Rubber band
3 Sealing ring
4 Glide bearing do not remove

Inner sealing ring for toothed rod pulling out






Install puller for sealing ring far enough so that the marking on the tool (arrow) matches the housing edge (only then will the claws engage behind the support ring)
Spread claws -2- of the tool by turning the spindle forcefully

NOTE: When introducing the tool, make sure that the cylinder race is not damaged

1 Support ring
2 Claws
3 Sealing ring
4 Tool No. 3315/11, or equivalent






Install tool No. VW 771, or equivalent, in the puller
Pull out sealing ring

Cleaning and checking parts

Before assembly, the housing must be checked for contamination (paint residue, chips, dirt) and thoroughly cleaned with compressed air and alcohol
Clean adhesive surface for adhesive tape in area of the slot with solvent (e.g. L160 or alcohol)
Check cylinder race for scoring or other damage. If scoring can be felt, replace entire steering gear
Clean toothed rod (remove old grease in the tooth pockets)

Checking toothed rod for scoringG






If corroded areas or deep scratches are not noticeable on the toothed rod, the toothed rod must be replaced
An evaluation of whether the toothed rod was damaged by force, e.g. by an accident, is not possible with this visual inspection







If slight scoring (arrows) can be seen/felt on the toothed rod that are only deep enough that they can be ground off with sand paper (grain 350-600) the toothed rod can still be used
Sand toothed rod with sandpaper in radial direction (this is only possible with slight scoring)
Check chamfer on the front sides of the toothed rod for damage, if necessary remove with a fine grinding stone and/or sandpaper
1 Toothed rod
2 Sand paper (grain 350-600)
3 Jaw covers

After sanding, lubricate toothed rod lightly
If the old toothed rod is used again, check the sealing ring for scoring.
If there is scoring that can be seen or felt, the sealing ring and the O-ring under it must be replaced.

Sealing ring on toothed rod, replacing






Press pliers together with slight pressure on the sealing ring
Pry out sealing ring and O-ring A- Needle nose pliers (standard commercial)
1 Toothed rod with piston
2 Sealing rod
3 O-ring

Sealing rings, installing on toothed rod piston






Slide mounting sleeve on toothed rod
Pull O-ring over tool and install in groove of piston
Lubricate sealing ring with hydraulic oil, pull over tool and install in groove of piston

Power steering gear assembling

NOTE: All sealing rings should be lubricated with hydraulic oil before installing.

Sealing Ring






Check whether the valve body housing -2- is absolutely clean on the inside, otherwise clean
Place sealing ring -1- on tool. The sealing lip -arrow- points toward tool
Drive sealing ring into stop
1 Sealing ring

Insure correct installation position of sealing ring in valve body






For better view, illustration shows valve tower in cross section

Inner Sealing Ring For Toothed Rod, Installing






Place sealing ring on tool
Ensure correct installation position of sealing ring for toothed rod
Drive seeing ring -1- into the cylinder pipe far enough so that the groove (arrow) on the tool matches the edge (arrow A) of the housing






1 Support ring
2 Sealing ring
3 Valve body housing

For better view, illustration shows housing in cross section

Toothed Rod, Installing In Housing

Grease teeth of toothed rod with part No. AOF 063 000 04, or equivalent, grease






Slide protective tube on to toothed rod to stop
Wipe excess grease off completely
No grease must get into the oil circulation system
Coat piston of toothed rod and protective tube with hydraulic oil






Install installation sleeve tool No. 3315/22, or equivalent, into the housing
Slide toothed rod into the housing
When sliding, make sure that the sealing ring is pressed into the groove of the piston without jamming
Slowly introduce the toothed rod into the housing

Pull protective tube tool No. 3315/13, or equivalent, off the toothed rod
Align teeth of toothed rod in such a way that they point toward the teeth of the pinion

Screw mounting sleeve tool No. 3315/18, or equivalent, on toothed rod and coat with hydraulic oil





Carefully slide toothed rod guide 1 over the toothed rod into the housing to stop
Slide toothed rod completely into the housing.
Place lock washer in the housing and press in far enough until the groove in the lock washer in the slot of the housing is visible





13Install new safety wire in the hole of the lock washer (arrow)
Pull safety wire in by turning the lock washer. (after pulling in, turn the lock washer approx. 1/2 revolution further)
1 Safety wire in repair kit is not formed as a ring, but supplied as a straight wire
2 Pliers (standard commercial)

Valve Body, Installing







Carefully drive lower ball bearing for valve body into stop
Ball bearing must not be tipped when driving in






Screw assembly mandrel tool No. 3315/17, or equivalent, on valve body
Lubricate valve body with hydraulic oil and carefully install by hand into the valve body housing (note position of toothed rod)
Make sure that the sealing ring in the housing is not damaged by the teeth of the pinion






Tape teeth of valve body with adhesive tape to protect the sealing ring.
Avoid wrinkles.
Install upper roller bearing for valve body (inscription on roller bearing points upward)
A Adhesive tape
B Valve body






Drive soaring ring in far enough sot that the groove for circlip in the housing is visible
Install circlip
Remove adhesive tape
Remove assembly mandrel tool No.3315/17, or equivalent,
Install hex nut for valve body and tighten, 30 Nm (22 ft. lbs.) with torque wrench tool No. SW 14 2, or equivalent.






Install locking screw
Grease pressure piece and spring in housing in old position
Install lock nut together with adjusting screw

NOTE: After tightening, the marking made during removal (arrow) on the adjusting nut and lock nut must match. If the toothed rod was replaced, before installing the he rods the steering gear must be readjusted

Adhesive Tape, Applying






Fill slot with sealing compound part No. AKL 450 005 05, or equivalent
Tape slot with adhesive tape 1
Adhesive surface must be dry and free from grease

Power Steering Gear, Adjusting With New Toothed Rod

If a new toothed rod was used, the steering play should be adjusted according to the following description.






Drill a hole 5.1 mm in diameter in the center of the adjusting screw (on the back side renter)
Thoroughly clean adjusting screw
Place toothed rod in center position (measure toothed rod excess right and left)
Install pressure piece and spring in housing if not done yet
Screw adjusting screw and lock nut far enough into the housing so that the markings match
Install gauge and set to "O" with approx. 1 mm preload (make sure that the key does not stick, front of key must not be crowned)

1 tool No. 3315/8, or equivalent
2 tool No. 3315/9, or equivalent,
3 tool No. 3315/1, or equivalent,
4 tool No. VW 387, or equivalent,






Screw right rod onto toothed rod and tighten by hand
Turn toothed rod radially from stop to stop, during this process observe pointer on gauge.

Needle run-out max. 0.10 mm
If needle run-out is greater than 0.10 mm, screw pressure piece slightly into housing
If the needle run-out is less than 0.10mm, screw pressure piece slightly out of housing

Tighten lock nut
Check needle run-out again, if necessary repeat adjustment
Remove gauge
Close hole in adjusting screw with a stopper from repair kit
First install clip -2- with gasket -1- in the hole






Apply 1 drop sealing compound, Part No. AMV 188 001 02, or equivalent, in the hole of the clip -arrow- and press plug -3- into the clip

TIE RODS, INSTALLING

See tie rods, removing and installing (TRW and ZF steering gear). Service and Repair