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Timing chain

rockethound said:
I'm buying a new motor and I'm wondering if should worry about having the shop replace the timing chain. Of even if there is a timing chain.

Timing chain is low priority for the 4.0L. I've never heard of one breaking and if it does, it's a non-interference engine anyway so there won't be any valve damage. If it's easy to get the cover off, it wouldn't hurt to check it for stretch but I've got over 260k miles on mine and it's not slapping the cover and/or making any noise.
 
At over 200k on mine, it wasn't making any noise, but there was definite wear on the plastic inside the timing cover, and a significant amount of slack. Yes, it was still running just fine. But it was time to replace it.

If it's a new motor, though, it should have a new chain, right? :) OTOH, if you're buying a used motor, if I didn't know the history, I'd at least pull the timing case cover and look at it.
 
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