Broken timing chain

[bleedsblue]

Hello everyone!

The timing chain on my 03 WJ 4.0 broke yesterday leaving me a few miles away from the cabin while elk hunting. But it was a lovely walk in the first blizzard of the year.

When I opened it up today, the cam gear looks like it got chewed up pretty good. I ordered the Jegs billet double roller timing set. Does anyone have any experience with this set???

[dwg86]

I’ve never heard of a Jegs bullet timing chain. Looking at your engine I’m assuming it’s a 1999-2004 grand Cherokee. The only Billet timing chain I know of for the late model 4.0 is SA Gear. What part number is the Jegs gear set?

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[Cheromaniac]

It's highly unusual for an OEM timing chain to break and the cam gears to wear on these engines.
You might want to look for a possible underlying cause (e.g. low oil pressure, blocked oil gallery) before you replace the timing set to prevent another failure. Your engine will probably also have some bent valves after being hit by the pistons.

[bleedsblue]

It is a 2003 WJ. After I did some further research, it is the S.A. set that is sold under the Jegs house name. It is a nice looking set though.

Oil pressure was good before it let go. The 4.0 is non-interface but I checked valvetrain anyway. I did not find any other issues. The timing chain that was on there is only a few years old. It was a Cloyes that I got from Russ when I built the motor. I couldn't find any glaring issues which has me a little concerned. Luckily, it isn't terribly hard to get to it if I have further issues.

But while I'm in there I'm changing out the rear main seal. I'm giving up on the Fel-Pro brand rear seals and trying the Mopar brand. I ordered one off Amazon, supposedly from a legit Mopar dealer and they sent me a dang Fel-Pro. I'll be hitting the dealer today as I need to be back up and running for the weekend. Wish me luck!