Get to a known starting point
Change all fluids
- Coolant
- oil
- trans fluid. Not a bad idea to drop the pan and change filter / clean magnets
- tcase fluid
- diff fluid (lubelocker gaskets are great)
- power steering fluid
- brake fluid
Inspect filters
- engine air filter
- cabin filter, if equipped
- Pop the heater core hoses out of the bracket, remove the bracket, then grab your engine oil fill riser and turn it counter clockwise. Peek inside the valve cover to see what, if any buildup/varnishing exists. Some varnish is fine - will look like a light brown coating. Anything chunky / thick / flaky looking - run short oil intervals until it cleans up. Don't bother with flush products. Just change it more often and let the oil do its thing.
- Take off belts, inspect idlers / pulleys / tensioners. Check water pump, alt, power steering pump.
- honestly wouldn't be a bad idea to just replace the fan clutch a part of the 'known good starting point'
- Verify a/c works or even better - take it to a shop for an evac/recharge so you know the fill is good
- change wipers. Or at least inspect them
- Make sure windshield washer fluid is windshield washer fluid and not water. That grows mold and makes the whole system gross
- Hook up a code reader, make sure nothing's pending. Check long term fuel trims. Anything deviating from +/- 10% is indicative of a vacuum leak. Usually on these rigs, it's intake gaskets
- Go through the underside of the vehicle and check for any fluid leaks. At a minimum, know what you need to keep topped up. Else find a path forward to fix it
- Make sure your defrost wires work. Rear window and both side mirrors
- Check all lights
- Check tire pressures
- Make sure your parking brake works. These rigs are notorious for de-laminating the parking brake shoes
General maintenance schedule.... At least the one I follow
- Oil change every 1-5k, depending on short trips / idle time. Somewhat arbitrary. I don't pay any attention to the built in monitor. Slap a code reader on there and see if anything's pending.
- Annually - change engine and cabin filters, brake fluid, p/s fluid, drain/fill trans pan, change my aftermarket inline trans filter and power steering filter. Rotate tires, manually verify 4wd/lo works. Check belts, check for fluid leaks, load test alternator and battery. You have a fan clutch on your rig - check this as well.
- Every 2 years - diff fluid, transfer case fluid, hook up pressure gauge to a/c ports and verify it's in spec
- Every 4 - change coolant (disconnect your lower radiator hose and heater core lines. Refill from the upper radiator hose)
Suggested addons:
- Trucool 40k transmission cooler
- PCV catch can - keeps the intake clean
- Reject oil-soaked (K&N) filters. Paper is desirable here
- I have a magnefine filter on both my power steering return line, and trans cooler line. It's installed on the hard line between radiator and external cooler. I heated up my intake and made a little divot so it clears and nothing rubs. Can post pics if needed.
For the varnish bit I mentioned above
Normal:
Change more often:
Drop your oil pan, valve covers, valley pan, clean up manually:
