On a 1999 Ford F-150 :
No , none of the engines ( 4.2 liter V6 / 4.6 liter V8 / 5.4 liter V8 ) have a REAR
timing CHAIN like the Ford 4.0 liter Single Over Head Cam , V6 engine does
with its ( 3 ) timing CHAINS
timing belt
Timing Belt
Chain
Timing chain
You do not need to replace the timing chain because there is no timing belt at all on Ford Taurus. It has a timing chain.
chain
The 3.8 litre V6 engine in a 1999 Ford Mustang has a timing CHAIN
It has a timing chain that should last the life of the engine.
The 1999 Ford Taurus does not have a timing belt. It has a chain that requires no maintenance.
The Ford F250 V10 models from the years 1999-2008 were equipped with a timing chain.
belt
It has a CHAIN.