Prepare main floor, inner longitudinal member and middle crossmember - AR63.40-P-1180-07CW

Fig 1: Identifying Mating Surfaces On Inner Longitudinal Member, Middle Crossmember And Main Floor

Courtesy of MERCEDES-BENZ USA

The following steps are shown on model 204.0.

1. Grind mating surfaces down to bare metal on connecting carrier (1), front crossmember (2) and rear crossmember (3) in crosshatched areas.

   Observe pretreatment of bonding surfaces (areas A, B, C, D, E and F).

   Prevent adhesion problems. To prevent adhesion problems, do not coat bonding surfaces with zinc dust paint suitable for spot welding (areas A, B, C, D E and F).

   Fig 2: Identifying Underfloor Separation Line Dimensions

   Courtesy of MERCEDES-BENZ USA

   Dimension: 

   1. a approx. 300 mm
2. Scribe separation line on underfloor (4) (area G).
3. Cut underfloor (4) at separation point (area G).
4. Remove remaining section on underfloor (4).
5. Grind mating surfaces on underfloor (4) down to bare metal in crosshatched areas.

   Grind spot weld flanges down to bare metal on both sides.

   Observe pretreatment of bonding surfaces (areas H, H₁ , H₂ , H₃ , and I).

6. Coat insides of spot weld flange with zinc dust paint suitable for spot welding.

   Prevent adhesion problems. To prevent adhesion problems, do not coat bonding surfaces with zinc dust paint (areas H, H₁ , H₂ , H₃ and I).

   Fig 3: Identifying Offset Reinforcement And Outer Inner Longitudinal Member Grinding Areas & Separation Lines

   Courtesy of MERCEDES-BENZ USA
7. Scribe separation lines on offset reinforcement (5) and outer inner longitudinal member (6) (areas K and L).

   Transfer separation lines from vehicle

8. Cut offset reinforcement (5) and outer inner longitudinal member (6) at separation line (areas K and L).
9. Remove remaining section on offset reinforcement (5) and outer inner longitudinal member (6).
10. Grind mating surfaces on offset reinforcement (5) and outer inner longitudinal member (6) down to bare metal in crosshatched areas.

    Observe pretreatment of bonding surfaces (area M).

    Grind spot weld flanges down to bare metal on both sides.

11. Coat insides of spot weld flange with zinc dust paint suitable for spot welding.

    Prevent adhesion problems. Do not apply zinc dust paint suitable for spot welding to bonding surfaces (area M).

    Fig 4: Identifying Outer Longitudinal Member Separation Lines & Mating Surfaces

    Courtesy of MERCEDES-BENZ USA
12. Scribe separation lines on outer longitudinal member (7) (area N).

    Transfer separation lines from vehicle

13. Cut outer longitudinal member (7) at separation line (area N).
14. Remove remaining section on outer longitudinal member (7).
15. Grind mating surfaces on outer longitudinal member (7) down to bare metal in crosshatched areas.

    Observe pretreatment of bonding surfaces (area O).

    Grind spot weld flanges down to bare metal on both sides.

16. Coat insides of spot weld flange with zinc dust paint suitable for spot welding.

Prevent adhesion problems. Do not apply zinc dust paint suitable for spot welding to bonding surfaces (area O).