...will downsize to the Sport Trac ...155k-200k seems to be the norm
...what are the usual issues with the 4.0L V-6?
..what mileage does timing sets, trans service, etc. become an issue?
...good source for reman engines?
If I were now shopping for a 2001~2005 Gen1 SportTrac,
* completely avoid 2001 Gen1 Job1; has pretzel shaped IntakeManifold & too many early model faults.
* prefer 2003 Gen1 Job2 SportTrac; easy-to-fix Pre-HEC electronics compared to 2004+Later HEC models.
NotoriousFailureItems for V6~4.0L~SOHC Engin + 5r55e Trans + 1354 TCase:
* Timing failures due to failing OilPressurized TimingTensioners; renew 2 Tensioners ASAP & every 100kMiles\12yrs, along with Plugs+Wires & OxSensors. Renew Oil+Filter ASAP & every 4kMiles\6mths.
* JunkPlastic ThermoStatHousing, cracks+leaks; swap in an Alumnum ThermoStatHousing ASAP.
* JunkPlastic HeaterControlValve, cracks+leaks; renew HCV or swap in a traditional Aluminum version.
* Delete 5/16"ID PCVValve CoolantWarmingLoop & associated 5/8~5/16~5/8" Tees+Hoses;
does NOT work & only serves as a source of leaks. New\cleaned PCValve every 33kMiles\4yrs.
* JunkPlasticTanked 2Row Radiator, cracks+leaks; swap in an AllAluminum 3or4Row version.
* Coolant drain+flush+renew every 33kMiles\4yrs along with new TStat+RadCap, & new\cleaned PCVValve.
* 5r55e Trans needs service ASAP & every 33kMiles\4yrs:
DropPan +DrainATF +ReTorqValvBodyBolts +NewFilter +NewPanGasket +New5~7qtsMerconV +AdjustBands.
Prefer to HandPump 3/4qt at TransDipTube & 1/4qt at SteeringTank every 4kMiles\6mths to refresh MerconV.
If never serviced, 5r55e will fail after 150kMiles; slipping & loss of reverse are typical 1st symptoms.
Inspect TransCooler tubing+hoses+clamps for leaks & rust, especially under\around radiator.
* 1354 TCase needs service ASAP & every 33kMiles\4yrs: drain +refill MerconLV.
4x4ShiftMotor & 4x4ControlModul are NotoriousFailureItems; relatively easy to diagnos & replace.
Excercise 1354 2WHi~4WHi~4WLo every month keeps ShiftMotor+ConMod+TCase from getting crusty.
* Diffs need service ASAP & every 33kMiles\4yrs; drain+refill 75w140@Rear & 75w90@Front.
Check diffs+axle+brakes for leaks, check diff\axle vent hoses+connections.
* EVAP Valve+Hoses leak, FuelFillVentHose leaks, FuelPump failure.
* FrontWheelHubs\Bearings, check wobble & renew as needed.
Click my signature below for many links to more info on these items & more.
Hope this helps.