Honestly pulleys shouldnt be a trail repair, those are items you should be checking every oil change. Maybe we should start more basic...
What should I be checking during an engine service?
So as a fleet mechanic I have a system for servicing trucks, I can literally check every inch of the truck change oil and oil and fuel filters in 45min. On my personal rigs it take me about 30min. Heres what I do...
Before starting the engine place foot on brake, check clutch free pedal, start engine, make sure the brake pedal goes down some as this indicates the booster is working.
Hold the brake hard for a few seconds, this will tell you if you have an brake fluid leaks.
Check windshield washers and wipers.
Stop engine and set brake (in an automatic manually select each gear and stop for a few seconds, go back to Park, leave engine running and check fluid it will be a little low as the fluid might be cold, but it should still be in the cross hatching).
Do a walk around checking tires and lights, if needed have a helper press the brakes and select reverse to check those lights also (I use a hood prop rod to apply brakes, and while its technically not 100% Kosher I will leave the key on but engine off and put the trans in reverse to check the lights).
Punch hole in oil filter to drain oil, break the drain plug loose and allow all oil to drain.
Shake down all steering components and grease them and ball joints if they are greaseable type.
Check fluid levels in differentials and transfer case, also transmission if manual (if it is a dipstickless automatic there is a procedure you will need to look up in factory service literature).
Shake down drive shafts, grease U joints if they are greaseable type, while checking U joints inspect engine and transmission mounts, suspension bushings, and springs, check differential, transfer case and transmission seals, check hoses and lines on under side.
Lift each corner of rig and shake the wheel placing your hands at top and bottom(play here will indicate ball joints) and shaking then front and back and shaking (play here will indicate steering components) to check for worn parts. Also pull the wheel in and out as this can help you identify wheel bearings. If doing a tire rotation this is also the time to check brake pads. Be sure to check inner and outer pads, the outer pad will naturally be slightly thinner than the inner but the pads should be essentially the same thickness, if they are not then that indicates a hanging up brake caliper, you should also check brake lines and ABS wheel speed sensor wires.
Install oil drain plug after inspecting gasket (if its an O ring you can usually reuse them a few times, if its a copper or aluminum washer it should be replaced each service)
Remove oil filter, lubricate new oil filter gasket with fresh oil, check filter head to ensure the sealing surface is clean and the old oil filter gasket is not still present (if oil filter is oriented in a way that you can pre fill it without spilling tons of oil, go for it. I typically do not pre fill my filters).
Refill engine with oil.
Check battery connections for corrosion and clean if needed, check accessory belts for cracks and glazing and for tension, inspect idler and tensioners (if any pulleys are running at an angle this indicates bearing failure, also if a belt is not running in the center of a pulley it indicates problems that need to be addressed).
Check oil level on dip stick (if you filled to capacity it should be over full as the filter will store some oil, make sure it is at least at the full mark on the dip stick).
Start engine, check for oil leaks at the pan plug and oil filter. Inspect accessory belt as engine is running noting any sounds or wobble form pulleys and tracking on idlers.
Stop engine and check tire pressure.
Check engine oil level and add as needed, check coolant level.
*For strut equipped suspensions bear in mind there is a ball bearing at the top of the strut, so give that guy a glance and a shake too
Theres my basic service. I do that on all my rigs every time I drop oil. Your first time following that it will take you a few hours, but once you get the flow it will become second nature and you will be able to do it very quickly.
Having a solid preventative maintenance procedure will eliminate a vast majority of trail repairs, at least for most people like us. For the most part overlanding really shouldnt be an activity that pushes a vehicle that far outside of its design parameters. We arent mud bogging or rock crawling, we are simply traversing rough terrain hopefully at a prudent speed. For that reason, I believe if you keep up on maintenance and inspections trail failures shouldnt be a primary concern. Granted there is always that situation that will create a problem so absolutely plan for failures, but I have never carried more than a full sized spare and U joints.
