Retrofit mechanical detachable parts - AN31.11-P-8080-05M

Model 220 

TRAILER COUPLING MECHANISM

1. Drill dia. 6.5 mm holes in side member at the positions (A) marked by punch marks, enlarge holes to dia. 14 mm, deburr and prime.

   The punch mark at the transition from the rear center assembly to the side member is usually hidden behind underbody sealant. Use the holes in the trunk side compartments as reference marks.

   Fig 1: Identifying Side Member Punch Marks

   
2. Measure the centers for the holes on the insides of the rear center assembly (as shown in Figures A and E), enlarge to dia. 32 mm, deburr and prime.
3. Draw out wiring harness channels (see Figs B, D) to left and right below the tail lamps in accordance with given dimensions (both positions are marked by punch marks), enlarge to dia. 36 mm, deburr and prime.

   Make sure that no cables on the inside are damaged.

4. Mark out the holes for the wiring harness brackets according to the given dimensions in Fig. C (all four holes are marked by punch marks), drill holes to dia. 6.5 mm through the outer skin only  , deburr and prime.

   Reference point (for dimensions) see arrow in Figure C.

   Fig 2: Identifying Rear Center Assembly Inside Holes Dimensions

   
5. Coat the opening (see arrow in magnified section) of the sealing wedges (5) with acid-free grease or soap and position on side member reinforcement (6).
6. Mount the left and right spacer plates (4) on the trailer coupling (2) and push in side member reinforcement (6) with sealing wedge.
7. Tighten the side member reinforcement (6) finger-tight with two bolts (11) on both the left and right.
8. Screw two threaded bolts (12) (see frame) into each of the left and right brackets of the trailer coupling (2); whereby the flange on the threaded bolt must be max. 13 mm  away from the tapped hole (see dimensions).
   Fig 3: Identifying Trailer Coupling Mechanical System Remove/Install Components

   
9. Fit alignment punch (18, 17) on inner threaded studs (see Figure).

   The alignment punches are different for the left (18) and right (17) sides.

10. Slide pre-assembled trailer coupling (2) with side member reinforcement (6) into vehicle frame side member.
11. Bolt trailer coupling (2) onto rear center assembly with three combination nuts (9) on each side, tightening the two outer combination nuts (9) first, removing the alignment punches and then fastening the inner combination nuts (9)

    The combination nuts (9) can be accessed via the trunk.

    Fig 4: Identifying Trailer Coupling Mechanical System Remove/Install Components

    
12. Tighten side member reinforcements (6) with counter tabs (8) and collared nuts finger-tight to the side member.

    The collared nuts (10) can be accessed via the side compartments in the trunk.

13. Use hexagon bolts (11) to attach trailer coupling (2) to side member reinforcement (6)
14. Attach side member reinforcement (6) to side member using collared nuts (10)
15. Pass control cable (1c) and release switch connecting cable (1b) through the hole under the left tail lamp and seal with grommet (i).
    Fig 5: Identifying Control Cable And Release Switch Connecting Cable

    
16. Remove bumper bracket (20).

    The bumper bracket is attached with four bolts (see arrows). The bumper bracket and bolts are no longer required.

    Only for vehicles on which the holes (see small arrows) in the bumper covering are fitted with metal bushings 

1. 17.1 Drive out metal bushing (see small arrows) and enlarge the hole to dia. 14 mm.

   This step is not required on bumper coverings without metal bushings.

2. 18 Bolt bumper bracket panel (3) provided onto bumper covering using bolts with captive washers (14) provided
   Fig 6: Identifying Bumper Bracket With Bolts And Metal Bush