Remove/install sealing ring on steering gear housing cover

AR46.20-W-1615-02B

Remove/install sealing ring on steering gear housing cover

Topical note

Notes on maintenance and repair work

AH46.20-N-0001-01H

Model

375, 970, 972, 974, 975, 976 with steering gear 765.840

Mercedes-Benz/ThyssenKrupp steering

Model

970, 972, 975, 976 with steering gear 765.844

Mercedes-Benz/ThyssenKrupp steering

 Steering gear

Number

Designation

Steering gear 765.84

BA46.20-N-1010-01FA

Screw/bolt, housing cover to steering gear housing

Nm

190

Repair materials

Number

Designation

Order number

BR00.45-Z-1017-06A

MB multipurpose grease, 400 g

A 001 989 34 51 11

1

Set steering gear to center position.

 The marking on the primary shaft (arrow A) must be aligned with the marking on the steering gear housing (arrow C).

2

Slacken counternut (9) and screw in setting screw (10) by hand using an Allen key (tightening torque approx. 10 Nm).

3

 Insert locking ring (11) between pitman arm (12) and steering gear housing; the heads of the screws (11.1) must point towards the pitman arm (12).

 The sealing ring in the steering gear housing must not be damaged.
Otherwise the steering gear will leak and will have to be replaced.

 Pay attention to different lengths of bolts.

4

Remove bolts (11.1) to allow locking ring  (11) to be fixed.

 The  locking ring (11) fixes the axial position of the pitman arm shaft (13), ensuring that the sealing ring in the steering gear housing cannot be damaged during the subsequent assembly procedure.

4

Housing cover

5

O-ring

7

Screw

9

Jam nut

10

Adjustment screw

11

Locking ring

11.1

Screw

12

Pitman arm

13

Steering shaft

B

10 mm

5

Unscrew bolts (7) and lock nut (9) from housing cover (4).

6

Screw in setting screw (10) until housing cover (4) lifts approx. 10 mm (B) off steering gear housing.

 Screw in the setting screw (10) by max. 6 turns.
If the housing cover (4) is pushed out any further, the bearing and the sealing ring in the housing cover (4) will be damaged.

 Collect escaping oil in a suitable container.

7

Remove O-ring (5).

 Remove the O-ring (5) over the housing cover (4), taking care not to damage the sealing surfaces.

8

Tape up the edge of the housing cover (4) all the way around using adhesive tape or crepe tape (8)

 The tape prevents the O-ring (5) from being damaged by the housing edge during assembly.

9

Grease new O-ring (5) with lubricant and pull over housing cover (4).

 Use the O-ring (5) from the repair kit. Observe the identification, the diameter (dimension) and the part number on the adhesive label. Use 85x2.5 O-ring.
Do not stretch the O-ring (5) any more than is absolutely necessary, and do not damage it during assembly.

10

Remove adhesive tape or crepe tape (8) free from residues from housing cover (4).

11

Press O-ring (5) against flange of housing cover until it abuts at the edge.

 Do not damage or twist the O-ring (5).

12

Remove the adjustment screw (10) by 4 turns. This has the effect of drawing the housing cover (4) onto the steering gear housing.

 The  locking ring (11) must be installed for this.
Otherwise the steering gear can be damaged.

13

Screw new screws (7) approx. 1 turn into steering gear housing.

14

Unscrew adjusting screw (10) until the housing cover (4) touches the steering gear housing.

 Tightening torque approx. 10 Nm.

15

Tighten screws (7) on housing cover (4) in a cross pattern   .

16

 Remove locking ring (11).

 To do this, screw in the screws (11.1) until there is sufficient space between the pitman arm (12) and the steering gear housing, and the  locking ring (11) can be removed.

17

Unscrew setting screw (10) until friction torque of setting screw (10) decreases noticeably (approx. 1/2 to 1 turn).

18

Screw lock nut (9) loosely onto adjusting screw (10).

 The counternut (9) is tightened only after the play of the pitman arm shaft has been adjusted.