I am Replacing the engine in my 2005 Ranger XLT 4x4 with one from a 2002 XLT 4x4 with 110k miles on it both are the 4.0L SOHC v6 engines. Is there anything I should service on the replacement engine before I install it and are there any trouble spots in the process I should be careful of. This will be my first engine swap any advice is appreciated.

 

Welcome to the forum

Yes, the 1997 to 2003 4.0l SOHC engines could have 2 faulty timing chain tensioners, for the long chains, passenger side rear and drivers side front
If engine was run with a bad tensioner then it would cause a rattle noise because a chain guide was broken, engine needs to be out to change the rear guides
The guides were not the issue, the tensioners were, but if old tensioner failed guide would break, so new tensioner after that won't help, guide needs to be replaced

Regardless of year these 2 tensioners should be changed every 100k miles or anytime you get a 4.0l SOHC engine, with or without the vehicle, just to be on the safe side, and start the clock ticking on the 100k mark for the next change


Also the plastic thermostat housing on this engine liked to crack and leak, give it a good inspection, a metal version is now available

 

Before installing "new" 2002 engine,
along with new OilPressurizedTimingTensioners
& replacing junk PlasticThermoStatHousing with new AluminumThermoStatHousing,
I'd also:
~ fully inspect all TimingComponents, specificly the PlasticGuides; consider renewing even if no visible damage.
~ replace old version of LeafSpring TimingTensioner for JackChain (behind front TimingCover) to new version.
~ replace RearMainSeal.
~ fully inspect+clean OilPump+Screen; consider renewing\upgrading.
If the "new" 2002 engine has the TimingBalancer, consider deleting\disconnecting that BalancerChain.