Life expectancy of 4.0 timing chain?

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Mar 1, 2008 | 02:48 AM
  #1  
Hello every one.
As the owner of a 97 Cherokee, I have managed to rack up 210,000 miles, and the 4.0 is still going strong. I have every intention of making it to 300K.
My experience with other brands of engines tells me the timing chain is something I need to think about checking out. We know that by removing the distributor cap and reviewing the backlash of the rotor when the engine is hand turned both directions, we can get a "idea" of the amount of wear on the timing chain.
My question is, what are other 4.0 engine owners experiences with the life expectancy of the factory timing chain?
sscott
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Mar 1, 2008 | 10:33 AM
  #2  
4.0's generally go their whole life without touching the timing chain. when you have symptoms of off timing, thats the only time i would worry about it.
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Mar 1, 2008 | 05:41 PM
  #3  
Thanks, sounds like good advice.I will worry about something else.
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Mar 1, 2008 | 05:53 PM
  #4  
Good info, I was a bit concerned about mine.
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Apr 4, 2021 | 08:20 PM
  #5  
For what it's worth - I'm pretty sure my 4.0 '96 Cherokee just broke the timing chain, not while under load, but at start. I'm about to dig into it, but I would like to know if this is an "interference engine"?

Read more: https://www.jeepz.com/forum/cherokee...#ixzz6r7UPKfAd
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Apr 4, 2021 | 10:06 PM
  #6  
The only real experience I have with. 4.0 timing chain is on my '99. It had ~210k on it when I replaced the timing chain. It was definitely looser than the replacement, but I wouldn't have called it loose enough to cause problems. I was doing some other things and decided to change it while I was there. It's not too bad of a job and allowed me to really clean up the front of the engine. The part I would take a close look at with that milage is the crank shaft dampener/harmonic balancer. The rubber tends to degrade over time and the outer part of the pulley walks forward and starts to cause interference problems with the fan. It's a relatively inexpensive part ($25ish) and you need a pulley puller to get it off but it can be done from underneath without removing anything extraneous if you are patient.
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Apr 4, 2021 | 11:06 PM
  #7  
Quote: For what it's worth - I'm pretty sure my 4.0 '96 Cherokee just broke the timing chain, not while under load, but at start. I'm about to dig into it, but I would like to know if this is an "interference engine"?

Read more: https://www.jeepz.com/forum/cherokee...#ixzz6r7UPKfAd

Google gives 2 definite answers

1) No
2) Yes

Not very helpful,

sounds like it close, you can get lucky or unlucky
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Apr 4, 2021 | 11:16 PM
  #8  
Sounds like there may not be an interference issue. Of course, I haven't taken the chain cover off yet, so I really do not know that the chain is the problem, but I have enough experience to think this is what happened, as well as to know that I am frequently very wrong.
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