It depends. The explorer has a front timing chain and rear timing chain assembly. While the rear cassette/tensioner rarely fails, it is far more expensive and difficult to fix. If the front tensioner is the problem (which it commonly is), then the repair is quite simple. Either way, a dealership will charge an arm and a leg to repair. I have heard that fixing both can be as much as 2-3 thousand dollars.
Timing chain.
The 5.0 L ( 302 cubic inch ) V8 engine has 1 timing chain
The 4.0 liter - OHV - engine has ( 1 ) timing chain The 4.0 liter - SOHC - engine has ( 3 ) timing chains The 5.0 liter - V8 engine - has ( 1 ) timing chain
Normally a timing chain will last the life of the engine and is replaced during a complete engine rebuild. No maintenance is normally required.
Timing chain
The Ford 4.0 liter SOHC engine has ( 3 ) timing CHAINS
1998 i30 has timing chain. just confirmed from my dealer.
chain
It has a timing chain and gears.
It uses a timing chain
A timing CHAIN
The Ford 4.0 liter OHV , V6 engine has ( 1 ) timing chain ( but the 1998 Ford Explorer XLT model , if it has the 4.0 liter V6 engine , would have the SOHC engine which has ( 3 ) timing chains )