One things for sure the spare that you need won't be the one you packed
We've not travelled to south America but have been through Western Africa a few times.
I take lightweight stuff such as:
Various relays.
Belts.
Crank sensor.
Plus "bodge it" type stuff such as liquid metal, zip ties, gas soldering iron etc.
A friend who works at a MB commercial dealer supplied the list below of his most common failure items.
Diesel quality in Africa is pretty variable but we had no issues. Maybe add a Racor secondary filter?
Also maybe get the Bluetec and dpf mapped out? But you're then running a non standard setup which I try to avoid. Purely from a reliability perspective.
OIL FILTER A642 180 00 09 £7.85
AIR FILTER A000 090 37 51 £11.76
FUEL FILTER A642 092 01 01 £22.70
BELT A001 993 38 96 21.36 X 690 £8.38
BELT A003 993 01 96 24.92 X 1969 £16.73
CRANK SENSOR A642 905 00 00 £24.73
FUEL PRESSURE RAIL SWITCH A006 153 65 28 £117.30
LEAK OFF PIPE A642 070 56 32 £63.32
WATER SWITCH IN FILTER A000 153 95 13 £44.19
THERMOSTAT A642 200 29 15 £40.63
BELT IDLER PULLEY A642 200 10 70 2 SAME FITTED £16.38
GEAR CABLES A906 260 17 51 PAIR £45.05
WHEEL BOLT A000 990 24 07 SIX REQUIRED £1.32 EACH
WIPER BLADES A906 820 11 00 PAIR £22.89
INTERCOOLER HOSE A906 528 22 82 £46.90
INTERCOOLER HOSE A906 528 03 82 £27.58
RADIATOR HOSE A906 501 05 82 £7.74
RADIATOR HOSE A906 501 04 82 £23.40
CLUTCH SWITCH A006 545 10 14 £8.41
BRAKE SWITCH A001 545 67 09 £9.92
BULBS AS REQUIRED
£567.18