Dismantling and assembling power assisted steering box (ZF) — VW

Dismantling

If not already sealed, seal pipe connections on power assisted steering box.

1 -
Plastic plug
2 -
Plastic plug

Clean exterior of power assisted steering box.
Open clamp and push back bellows.

Clamp steering box with rack in a vice and unscrew the track rod.

Note:

Use vice clamps, check vice clamps for impurities e.g. metal filings or similar and thoroughly remove.

If a spanner face is present on the rack then use an open jaw spanner to counter hold. The rack should not then be tensioned in a vice.

Remove cover.

Notes:

Do not move position of adjusting screw (arrow) in relation to lock nut!
Cover is lightly spring-loaded.

Remove thrust piece.

1-
Expanding pliers (commercial type)

Remove lower valve body plug.

1 -
Plug

Remove Torx bolt for valve body.

1 -
Open jaw spanner 14 mm AF (commercial type)
2 -
Torx socket insert E 10 (commercial type)
3 -
Ratchet 3/8 '(commercial type)

Remove circlip with pointed pliers -1-.
Drive valve body out upwards from below.

Push rack completely in direction of valve body.

Turn circlip so that the circlip pointed ends are in the housing groove (arrow).

First lift circlip with a screwdriver, then pull out with pliers.
Before pulling out the rack clean housing opening with compressed air.
Remove any impurities and any metal particles.
Pull rack with rack guide to the right out of housing.

A -
Screwdriver, B - pliers (commercial type)

Removing centre roller bearing for valve body.

Drive centre roller bearing out upwards.

A -
Internal puller e.g. Kukko 21/4
B -
Drift

When fitting the puller -A- ensure that the claws (arrows on illustration N-48-0058 Page
48-97
) locate properly under the roller bearing. The puller must not be spread too far otherwise the roller bearing seat in the housing will be damaged or the roller bearing can jam in the housing.

To ease fitting the puller it is recommended that a rubber band is placed around the claws, for ease of illustration the figure shows the housing sectionalised.

1 -
Internal puller e.g. Kukko 21/4
2 -
Rubber band
3 -
Roller bearing
4 -
Housing

Removing valve body oil seal

Drive oil seal out upwards.

A -
Internal puller e.g. Kukko 21/4
B -
Drift

When inserting the puller -A- ensure that the claws (arrows on illustration N-48-0058 Page
48-97
) locate properly under the oil seal. The puller must not be spread too far otherwise the oil seal seat in the housing will be damaged or the oil seal can jam in the housing.

To ease fitting the puller it is recommended that a rubber band is placed around the claws, for ease of illustration the figure shows the housing sectionalised.

1 -
Internal puller e.g. Kukko 21/4
2 -
Rubber band
3 -
Oil seal
4 -
Housing

Drive out lower ball bearing with VW 439.

Removing inner seal for rack.

Drive seal for rack out of housing.
Remove pipes from valve body housing to cylinder pipe.
Clean pipes, housing. Check threaded connections for impurities (rubber remains, metal particles).

Assembling

Before assembling, the housing must be checked for impurities (paint residue, metal particles, dirt) and thoroughly cleaned if necessary.

Notes:

Ensure meticulous cleanliness is observed when assembling!
Check cylinder bearing surface for scoring or other damage. If scoring can be felt the steering box must be replaced complete.
Check the rack for scoring => Page
48-101
Coat oil seals with hydraulic oil before installing.

Install seal for valve body

The sealing lip (arrow) faces upwards to valve body splines -1-.

For ease of illustration figure shows the housing sectionalised with valve body installed. The valve body for ease of illustration is lifted slightly.

Drive seal in for valve body onto stop.

Drive centre roller bearing for valve body onto stop.

Installing rack inner oil seal

The seal -3- lip (arrow) points to cylinder -4-

1 -
Valve body
2 -
Support ring
3 -
Seal
4 -
Cylinder

For ease of illustration the housing is shown sectionalised.

Fit support ring -1- and seal -2- onto tool.
Drive rack seal onto stop in housing.

When the groove (arrow) on the tool aligns with the housing edge (arrow A) then the seal is seated correctly.

Checking rack for scoring

The rack must be replaced if it has corroded areas or visible deep scoring.

Is available as a replacement part, allocation

=> Parts microfiche

With this visual check it is not possible to assess whether the rack has been damaged by force e.g. damaged during an accident.

If light scoring (arrows) is visible/perceptible on the rack, which are only so deep that they can be rubbed-out with abrasive paper (grade 350...600), the rack can be reused.

Rub down rack with abrasive paper in a radial direction. (This is only possible with light scoring).

Check chamfer on face side of rack for damage, if necessary eliminate with a fine whetstone and/or abrasive paper.

1 -
Rack
2 -
Abrasive paper (grade 350...600)
3 -
Vice clamps

If the old rack is to be used again, check the seal for scoring. If scoring is visible or perceptible the seal and O-ring underneathed must be replaced.

Lubricate rack with hydraulic oil (protection against corrosion)

Renewing rack seal

When the seal is replaced it must be replaced with a new seal of the same colour!

Is already fitted to new racks which are supplied as replacement part

Lightly press seal together with pliers.
Lever out seal and O-ring.

A -
Pointed pliers (commercial type)

Observe allocation of O-ring to seal!

Is already fitted to new racks which are supplied as replacement part

O-ring 30.0 x 1.78 / white seal
O-ring 31.0 x 1.5 / black seal

Push fitting sleeve 3315/19 onto rack.
Pull O-ring over the tool and insert in the piston groove.

Coat seal (note colour) with hydraulic oil, pull over the tool and insert in the piston groove.

Fitting the rack

Clean and oil the rack (remove old grease from teeth)

Apply AOF 063 000 04 grease to rack teeth.
Push protective tube over rack -1- onto stop.
Completely wipe off excess grease.

No grease must be allowed to get into the oil circuit!

Coat rack piston and protective tube with hydraulic oil.

Place guide sleeve 3315/21 in the housing.
Slide rack into the housing.

When sliding in ensure that the seal is pressed into the groove in the piston without jamming.

Guide rack slowly into the housing.
Pull protective tube 3315/5 off rack.

Align rack teeth so that they face towards pinion teeth.
Screw fitting sleeve 3315/16 onto rack and coat with hydraulic oil.
Carefully slide rack guide -1- over the rack into the housing onto the stop.
Push rack fully into the housing if this has not already been done.
Insert circlip so that the opening of the circlip is opposite the groove in the housing.

Drive ball bearing in onto stop with VW 421.
Grease with steering box grease AOF 063 000 04

Ball bearing must not be canted when driving in

Screw fitting tool 3315/17 onto valve body.
Lubricate valve body -1- with hydraulic oil and carefully fit into valve body housing by hand. (Observe position of rack).

Ensure that the seal in the housing is not damaged by the pinion teeth!

Cover valve body teeth with adhesive tape (e.g. Tesafilm).

A -
Valve body
B -
Adhesive tape

Slide sleeve with roller bearing carefully onto valve body.
Drive "sleeve" into the housing until the groove for the circlip is visible.
Insert circlip.
Remove sticky tape/sellotape.
Remove fitting tool 3315/17.
Screw Torx bolt into valve body and tighten (35 Nm) counterhold with open jaw spanner 14 mm AF.

Fit plug ( 30 Nm) and lock using centre-pops.
Grease thrust piece with AOF 063 000 04 grease.
Insert thrust piece, spring and disc into housing.
Install cover with adjustment bolt. Adjustment is carried out when box is installed => Page
48-109
.

Install track rods

Clamp steering box with rack in a vice and screw on track rod.

Note:

Use vice clamps, check vice clamps for impurities e.g. metal filings or similar and thoroughly remove.

Installing bellows

Check bellows for wear such as cuts, cracks and check bellows sealing surface for cleanliness.
Install bellows but first turn track rod so that ball joint pin is in the correct installation position.
Fit pressure balancing pipe.

Note:

Ensure that the bellows and the pressure balancing pipe are correctly installed,, => Bellows installation position.

Bellows installation position

1 -
Bellows
2 -
Housing

When installing the bellows ensure that the lip (arrow) lies against the housing.

Clamp installation position

1 -
Clamp
2 -
Pressure compensation pipe
3 -
Bellows
a -
approx. 90°

Tension hose clip with pliers V.A.G 1275.

Only use original hose clamps