Originally Posted by 32krazy!

this should be what your looking for

The center bolt is an M16 x 1.5 x 77 bolt. The MB part number is 112 031 00 71.
This shank length of this bolt is 77 mm long. As you all know, this bolt is designed to stretch slightly upon proper torquing.
Figure 4 shows that according to MB, the center bolt can be used if the shank length is less than 78 mm long.