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

TRAILER HITCH MECHANICAL SYSTEM

Number	Designation		Model 211 swing-away trailer control unit valve
BA31.11-P-1001-01C	Nut with spring washer, trailer coupling to rear center assembly	Nm	50
BA31.11-P-1002-01C	Bolt, trailer coupling to longitudinal member reinforcement	Nm	110
BA31.11-P-1003-01C	Bolt, side member reinforcement to frame side member	Nm	50

Remove crossmember (6).
Crossmember (6) is no longer required.

Fig 1: Identifying Crossmember
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
Remove plug (7, 8) from rear center section.
The stop plugs (7, 8) are no longer required.

Fig 2: Identifying Rear Center Section Plugs
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
Remove stop plugs (9) from left vehicle longitudinal member and right vehicle longitudinal member.
The stop plugs (9) are no longer required.

Fig 3: Identifying Left Vehicle Longitudinal Member Stop Plugs
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Fig 4: Identifying Right Vehicle Longitudinal Member Stop Plugs
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
Position seal (4) in left and right vehicle longitudinal member.
Check seal (4) is correctly positioned. The arrow on the seal (4) must point upward.

Fig 5: Identifying Seal Installation Position In Vehicle Longitudinal Member
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
Insert left longitudinal member reinforcement (2) in the vehicle's left-side longitudinal member.
The left longitudinal member reinforcement (2) is marked with an adhesive label (arrow).
Insert the right-side longitudinal member reinforcement (3) into the right-side longitudinal member.
The right longitudinal member reinforcement (3) is marked with an adhesive label (arrow).

Fig 6: Locating Left And Right Side Longitudinal Member Reinforcement Adhesive Label
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
Screw left longitudinal member reinforcement (2) and right longitudinal member reinforcement (3) finger-tight to vehicle longitudinal members using two M10 25 self-locking bolts (5) with washers each.

Fig 7: Identifying Left Side Longitudinal Member Reinforcement And Self Locking Bolts
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Fig 8: Identifying Right Side Longitudinal Member Reinforcement And Self Locking Bolts
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
Mount trailer hitch crossmember (1) on left longitudinal member reinforcement (2) and right longitudinal member reinforcement (3) and screw on hand-tight each with two microencapsulated bolts M12x1.5x35 (13).
Guide the cable and wiring harness through the openings and seal with grommet (30).

Fig 9: Identifying Trailer Hitch Crossmember, Left And Right Side Longitudinal Member Reinforcement, Microencapsulated Bolts And Grommet
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
Place the bracket (14) on the threaded bolt on the left-side cross member.
Screw two self-locking M10 combination nuts (15) with spring washers on finger-tight to secure the bracket (14) to the inside of the rear center section.
Screw trailer hitch crossmember (1) finger-tight with two self-locking combination nuts M10 (15) with spring washers onto outer left rear center section.
Screw trailer hitch crossmember (1) finger-tight with two self-locking combination nuts M10 (15) with spring washer each onto right rear center section.

Fig 10: Identifying Trailer Hitch Crossmember, Self-Locking M10 Combination Nuts And Bracket
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Always adhere to the specified tightening sequence.
Tighten both self-locking combination nuts M10 (15) with spring washer at the outer left and right of the rear end center assembly with the specified torque.
Tighten both self-locking combination nuts M10 (15) with spring washer on inner left and right of rear center section respectively with the specified torque.

Fig 11: Identifying Self-Locking Combination Nuts M10 With Spring Washer
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Always adhere to the specified tightening sequence.
Tighten left longitudinal member reinforcement (2) and right longitudinal member reinforcement (3) each with two self-locking bolts M10 25 (5) on longitudinal member with the specified torque.
Tighten both microencapsulated bolts M12 1.5 35 (13) on left and right of trailer hitch crossmember (1) with the specified torque.

Fig 12: Identifying Left And Right Longitudinal Member Reinforcement, Self-Locking Bolts M10 And Hitch Crossmember

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.