Hello there new to playing with forums but I had recently purchased a 2001 Ford Ranger 4X4 Supercab with the 4.0 SOHC engine. Got a really good deal on it and one the cleanest vehicles Ive ever seen for being on almost 20 years of life. Eventually gonna start lifting and playing with the truck some more after giving it a couple months to get situated with it will most likely be starting a build thread at some point but excited to get working with it.

 

Welcome to the forum

2001 Ranger with 4.0l SOHC was first year with that engine, there were issues with timing chain tensioners from 2001 thru 2003, so if there is no record of the 2 long change tensioners being swapped out I would consider doing that sooner than later
If tensioner gets too loose then you will hear a rattle on start up and sometimes mid-RPM range, at that time engine needs to be pulled out to change the rear timing chain and guides, so best not to get that far, lol.
Only use Motorcraft(Ford) tensioners for this, they cost alot more but are worth it for this application, it is a DIY project, just wrench work

You will have a 5R55E automatic. or a M5OD-R1HD manual transmission, with a BW1354 electric shift transfer case, all use ATF, yes even the manual transmission

Shift transfer case into 4low and back to 2WD once a month, just sitting in driveway, don't have to drive it in 4low, this keeps the electric shift motor's brushes clean and gears lubed, so when you actually do need 4WD it will work

You have Live Axles on front wheels, always locked, 2WD and 4WD is done in transfer case only