Crf136n

So my '96 xj 4.0 with 235k on it had a leaking rear main seal I finally had enough of and decided to tackle tonight. While I was under there I was giving everything a once-over and I have no idea what inspired me to poke at the timing chain as I have never done that on any of the other half dozen or so rear main seal jobs I've done...ITS GOT A LOT OF PLAY!!! As in 3/4 to one inch of play. Is this normal!? The jeep otherwise runs fine, idles smooth, good power, and only indication of any issues would be that slight warm engine clacking the high mileage 4.0's get (which also concerns me). This xj is a former cop car so I dont assume its had an easy life. Thoughts? Should I be worried about this?
Thanks in advance

James

Radi

1/2 inch or less is normal. If you are seeing an inch I'd think about replacing the timing set.

Cherockee

Yes. replace that asap. While the 4.0L is not an interference motor it's not fun with a chain skips a tooth (or twenty), especially at highway speed. If you plan on keeping it then swap in a new set. Not real expensive, just a lot of work.

Crf136n

Thanks for the quick reply; I guess a timing chain job is in the not-too-distant future then. Def more than 1/2 inch play. While in the meantime I risk the timing chain failure, at least its not leaking oil now Thanks again!

-James

freegdr

Timing chains will have one loose side and one tight side replace it when you can but dont drive around like its gonna blow up and scatter parts all across the highway at any secon im running 200,000 on mine .Never heard of one breaking in years . or skipping .

cruiser54

I agree. My experience exactly.

Cherockee

I've had a metal chain skip on me once back when I was in college. I was doing about 70mph on the highway when it went, but surprisingly it continued to run although not very well. And luckily once I replaced the timing chain set the engine ran fine with no damage.

So, moral of the story is- chains do skip. It can happen. If breaking down is not a concern for you then yes, go ahead and drive it like you stole it. Sure it could last for years, or days.

Your call.