The best supply of the spare parts would be if the service van carried a second totally disassembled rally car. However, even top WRC teams cannot do this. So, if you cannot have everything you must have only the best selection of parts you can take with you.There are ways to determine what should be on such spare parts list.
There are only three criteria for such parts:
1. The parts that will brake during the rally
No one knows which parts will be needed during the rally. By experience list of such parts can be approximated, but as live has it, among the parts that actually brake there are always some which the service did not take from garage shelf.
2. The parts which the service team is able to change during the rally
Some teams’ mechanics are capable of replacing a gearbox in 30 minutes, a rear diff in 15 and front or rear suspension on one side in 15 minutes. Changing the head gasket or clutch assembly during extended overnight service is fairly common. The question is what is your team’s service capable of changing during the rally. The rule is simple do not load it onto the Service Van what your service cannot use during the rally.
3. The parts which are allowed to be changed during the rally
Some rallies do not allow changing some parts during the event (i.e. the engine). Thus loading a spare engine it onto the Service Van is counterproductive.
So what part to take:
Ignition: distributor, cap, rotor, condenser, cables, spark plugs, coil, ignition module – the works.
Engine ancillaries: clutch disc and pressure plate, water pump, alternator, oil pump, oil filter, air filter, fuel filter, gaskets, oil sump, fan belt, timing belt, starter.
Suspension: wheel bearings, brake pads, rotors, copper rake line, CV joints, suspension and steering ball joints with rubber boots, muffler hangers.
Other: Wiper arms and blades, etc.
Selection of spare parts available on the service car is a never ending process ruled by the most scientific approach the trial and error method.