BMW X5: Welding And Soldering Steel Parts
IMPORTANT: Comply with the following topics from "Body, General":
Safety regulations.
Handling electrical/electronic equipment, airbags and restraint
systems.
A. Welding steel parts:
- General information
- Work materials
- MAG welding:
- Steel welding apparatus (refer to WORKSHOP EQUIPMENT PLANNING
CD,
Chapter 7).
- Steel welding wire - G3SI1 (SG2) or alternatively G4SI1 (SG3)
- Welding mask
- Gas bottle containing inert gas (82 % argon, 18 % CO 2)
- Resistance pressure spot welding:
- Spot-welding apparatus (refer to WORKSHOP EQUIPMENT PLANNING CD,
Chapter 7).
- Protective goggles
- Preparations for MAG and spot-welding
- Remove the paint coating in an area of approx. 30 mm around the weld
seam or spot.
- The zinc coating underneath must be removed during the MAG
welding operation.
- It is not necessary to remove the zinc coating underneath during
spot-welding.
- Remove the paint coating on the reverse side of the weld seam or
spot.
- Contaminants will otherwise enter the weld pool via the root of
the weld seam.
- An insufficient electron flow prevents an optimum spot-weld
joint.
- Coat all metal overlaps and weld spot flanges with welding primer.
- To determine the optimum electrode contact force for spot-welding,
carry out spot-weld
shear tests on sample metal sheets.
- In order to keep the electron flow short during MAG welding on the
body, you must if
possible attach the ground terminal directly to the component to be
welded.
- Welding
- During MAG welding, the weld gap must be kept as small as possible.
The larger the weld gap, the lower will be the strength of the joint.
- During spot-welding, the metal flanges to be joined must be placed
as close together as
possible without gaps.
The larger the gap, the lower will be the strength of the joint.
Minimum gap between welding spots 25 mm.
- Subsequent treatment of weld joints:
- When grinding a weld seam, do not grind thin the base material next
to the seam.
- After joining, clean all weld seams and spots with a stainless steel
wire brush.
- Remove burnt paint with a stainless steel wire brush.
- All weld joints sealed off with body sealing compound in original
state must be primed and
sealed off again thoroughly after repairing. Replace damaged or removed
antinoise
compounds.
B. Soldering steel parts:
- General information
- The following procedures are used for repairs:
- The MIG soldering procedure is not used in repairs for strength
reasons. MIG
soldered/brazed seams used in series production are replaced in repairs
by MAG weld seams.
- Areas brazed in vehicle production are joined during repairs with
the same procedure.
- It is possible when straightening steel parts to correct
irregularities smaller than 2 mm with
filler.
If in exceptional cases the irregularities are in excess of 2 mm, these
areas must be tinned.
Only visible areas of the outer skin and on the support carrier must be
tinned.
All areas which have covers on the vehicle are not to be tinned.
NOTE: Only applicable within the European Union!
European used-car regulations prohibit the use of tin containing lead
in motor vehicles
introduced after 01.07.2003!
- Work materials
- Gas brazing:
- Tube pack and torch (gas torch)
- Brazing solder
- Gas bottles (oxygen and acetylene)
- Welding goggles
- Tinning:
- Tube pack and torch (torch for tinning)
- Tinning paste
- Tin
- Gas bottle (acetylene)
- Protective goggles
- Preparations for brazing/tinning
- Heat brazed joints to be opened with an autogenous flame. Lift off
remaining metal and
remove remaining brazing solder with a wire brush.
- Remove the paint and zinc coating in an area of approx. 30 mm around
the seam to be
soldered.
- Remove the paint and zinc coating in the tin-plating area and
approx. 30 mm beyond.
- Brazing/tinning
- Execute brazed seam without overheating the solder and with low heat
dissipation. If
necessary, use heat protecting paste.
- Subsequent treatment of brazed joints:
- Remove burnt residual zinc completely. Straighten, grind and tin
visible connection points.
- Remove burnt paint with a stainless steel wire brush.
READ NEXT:
In the case of a partial replacement piece, a body component is cut at a
point described in the repair instructions.
A reinforcement plate is welded in to ensure sufficient strength.
Follow notes f
Read contents of Body, General.
The steel-aluminum mixed construction is used on the vehicle.
Observe specific procedure.
Remove or cover those vehicle components in the repair area which are
susc
SEE MORE:
Special tools required:
11 4 361
11 4 362
11 4 363
11 4 364
11 9 200
Necessary preliminary tasks:
Remove fan cowl with electric fan
Remove alternator drive belt
Remove drive belt tensioner
NOTE: The procedure is the same as for the crankshaft radial seal.
Expose removal openings on seal
Sport program M/S
Principle
The shifting points and shifting times in the
Sport program are designed for sportier handling.
The transmission, for instance shifts up
later and the shifting times are shorter.
Activating the Sport program
Press the selector lever to the left from selector
lever posit