Crank Bolt failure
Nice read here on sleeving the crank
Those engines are notorious for that problem.
Bolt has been revised twice old bolts are these - oldest on the left and first revision on the right

The new 3500 bolt is LEFT - LL1100A141
The New 3000 bolt is RIGHT - 1101A022

This is based on info given by wincaps and Mitsubishiparts.net
Wincaps give this part number for the Gen2 3500 longwagon
- 030313 - MD172725

it looks like the OLD bolt on the right in the top picture
when I enter the part number MD172725 into mitsubishiparts.net it gives this revised part number which is the bolt on the left in the picture above as mentioned part number - LL1100A141

Credits : Thanks FrankR for helping me originally with the different crankbolts. :kewl: