hey guys, i have a knocking sound coming from the front of my 4.0L down low, and im just wodnering what the life span for the timing chain on a 4.0L is.....i want my jeep to last me a bit longer but i was thinkin now that knocking sound could be a bad timing chain ?? it starts right up but seems down on power sometimes, i dunno.....anyone know how long a timing chain usually lasts on a 4.0L has anybody changed one and if soo what is hard ??
Well I never had to change one as most dont stretch or break too often.
But to check the chain you can remove the distributer cap and rotate the motor by hand using the belt or pulleys. Turn counterclockwise to take the slack out of the chain, then slowly turn clockwise, noticing how far before the rotor moves.
If the pulleys go an inch or so the chain is stretched and should be changed, it is usually noticeable by more of a slapping noise.
I'm at 213K on the original chain, and I am just going to let it ride for now. I had a friend at work claim that he threw one at 241K, and that was the end of the road for him. I do not believe that throwing a chain always ends happily with the installation of a new chain.