LEMON Manuals: Even more car manuals for everyone
Home >> BMW >> 2012 >> 740Li >> Repair and Diagnosis >> General Information >> OEM General Information >> 7 Series - Introduction >> Body Overview >> Bodyshell (body-in-white) >> Function >> Notes

Bodyshell (body-in-white): Function: Notes

The cast-aluminum spring mounts strengthen the front section and improve drive dynamics. Lightweight construction with aluminum in the front section contributes to uniform axle load distribution.

The aluminum roof lowers the center of gravity of the vehicle as a whole, thus contributing positively to drive dynamics.

The increased-strength multiphase steels and very-high-strength hot-formed steels combine low weight with maximum strength for the safety passenger cell, thus contributing very significantly to passive safety.

Interested readers will find a wealth of background information on nomenclature and abbreviations in the Product Information entitled "Basics of High-Strength Steels".

Aluminum roof on bodyshell 

Fig 1: Identifying Aluminum Roof On Bodyshell
G06896212Courtesy of BMW OF NORTH AMERICA, INC.
INDEX EXPLANATION CHART

Index Explanation
1 HC180BD, HC220BD, HC220YD, HC260BD, HC260LAD, HC260X, HX260BD
2 DX54D
3 HC300BD, HC300LAD, HC300X, HC340LAD, HC340X, HC380LAD
4 HC400T, HC420LAD, HC450X, HC600C, HD680C, HC900WD, HC950W, Docol 1200
5 Others
6 Aluminum

Material mix 

Fig 2: Identifying Bodyshell Material Mix
G06896213Courtesy of BMW OF NORTH AMERICA, INC.
INDEX EXPLANATION CHART

Index Explanation
1 HC180BD, HC220BD, HC220YD, HC260BD, HC260LAD, HC260X, HX260BD
2 DX54D
3 HC300BD, HC300LAD, HC300X, HC340LAD, HC340X, HC380LAD
4 HC400T, HC420LAD, HC450X, HC600C, HD680C, HC900WD, HC950W, Docol 1200
5 Others
6 Aluminum
Fig 3: Identifying Bodyshell Material Mix
G06896214Courtesy of BMW OF NORTH AMERICA, INC.
INDEX EXPLANATION CHART

Index Explanation
1 HC180BD, HC220BD, HC220YD, HC260BD, HC260LAD, HC260X
2 DX54D
3 HC300BD, HC300LAD, HC300X, HC340LAD, HC340X, HC380LAD
4 HC400T, HC420LAD, HC450X, HC600C, HD680C, HC900WD, HC950W, Docol 1200
5 Others
6 Aluminum

In order to optimize anti-corrosion protection, the bodywork of the F01/F02 is constructed primarily from fully galvanized sheet, special-steel sheet and aluminum sheet.

Welding, adhesive bonding and riveting are the connection techniques used.

Where sheets are doubled up the design is such as to minimize the contact surfaces. This helps prevent bondline corrosion.

All other anti-corrosion protection and sealing measures depend on the extent to which the doubled sheets are exposed to moisture/water.

In particularly critical areas, expanding foam parts are used to seal the body cavities against the ingress of water. All doubled sheets in wet zones are double-sealed and, if necessary, they are also treated with wax as an extra sealant.

Doubled sheets in dry zones (above the waistline) are sealed not against corrosion as such, but if necessary to avoid the ingress of dust.

Corrosion-critical material pairing is avoided. The combinations of material substrates and joining technique were chosen with meticulous care in order to avoid corrosion risks.