A timing chain is not a maintenance item that needs replacing at a set time or mileage. You replace it when a major overhaul is done. It will normally last until that is necessary. If you hear it making noise or the engine performs poorly or you can't keep the engine in time, then it may need replacing.
timing CHAIN
The timing chain does not have a recommended change interval and should last for the life of the engine.The timing chain does not have a recommended change interval and should last for the life of the engine.
On a 1996 Mercury Cougar : The 3.8 liter V6 engine has ( 1 timing CHAIN ) The 4.6 liter V8 engine has ( 1 timing CHAIN to each cylinder head , so there are 2 timing CHAINS )
It must have a timing chain because Gates ( they make timing belts etc. ) only lists a timing belt for the 4 cylinder engine on a 2000 Mercury Cougar
The 4 cylinder has a timing belt
it has a timing chain !
The 3.8 liter V6 engine in a 1991 Mercury Cougar has a timing CHAIN
The timing chain does not require replacement unless it has failed.
at what milage should the timing chain be replaced on a 95 ford aerostar
It has a cam chain that normally requires no maintenance.
You are correct that the SL2 uses a timing chain. However, since it uses a timing chain it does not need to be replaced as does the timing BELT. In general, a timing chain should last the life of the engine.
Chain and it is a very (~1000.00) costly fix.