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TJ4Jim 09-24-2013 05:58 PM

Timing Chain Replacement
3 Attachment(s)
Dove into the replacement today as the noise was pissing me off. Sounded like a diesel when it warmed up. Using the stethoscope it was pretty clear where the noise was coming from. I was just hoping to find evidence of slap because unless it's under torque it really is not evident when trying to flex the chain.

The rub guard was missing with pieces scattered about and I was happy to find rub marks on the inside cover. You can see 2 sets of rubs on the tabs that hold the rub strip.

Digger84 09-24-2013 07:08 PM

Makes sense as unless the crank is spinning and the chain dragging the cam around against valve spring resistance any chain slack is divided onto both sides but when the motor is running the side pulling the cam gear is tight so all the slack is on the side where the crank sprocket is pushing the chain toward the cam sprocket

If with chain on and cover off and plugs removed if you crank with a wrench on the crankshaft in the normal direction of engine rotation up until you feel most cam resistance but not past that point it should put all the chain slack essentially on one side

TJ4Jim 09-24-2013 07:24 PM

Well I found the rub marks on the side opposite the tensioner so that's on the side where it's being dragged around right ? As the chain feeds into the crank sprocket.

TJ4Jim 09-26-2013 05:18 PM

Finished the replacement and started her up last night and what a difference. Went from a Detroit diesel to a singer sewing machine.

Replacement went very smooth, just glad I did not follow the Chrysler service manual. No wonder they charge so much at the dealerships. The tell you to remove the alternator, AC compressor and recommend removing the water pump !
None of these devices were remotely in the way, once you remove the fan housing, fan and pulley it's wide open to the timing cover.

Digger84 09-26-2013 05:29 PM

Great success! Is your jeep a 4 or 6 cylinder as I thought only the 4 had the spring loaded tensioner

Does your TR6 have the overdrive unit? Had a few TR3 in my youth but never a 6

TJ4Jim 09-26-2013 05:39 PM

It's a 2.5 I4 There was one pic that shows the tensioner spring fully extended which told me it was done.

I wish I had the overdrive. Almost nailed one from a local part out until he realized what it was worth.

Unfortunately the TR6 is a Hurricane Sandy victim, she took about 18" of salt water but fortunately did not enter the engine. She is in line for my repair spot in the garage. Hopefully she winds up a survivor.

t3456 09-26-2013 06:23 PM

How long did it take you to do all that? I've never done one before. I was thinking about doing mine, but it seems intimidating.

TJ4Jim 09-26-2013 07:14 PM


Originally Posted by t3456 (Post 4886401)
How long did it take you to do all that? I've never done one before. I was thinking about doing mine, but it seems intimidating.

I had not done a straight replacement either but it was very straight forward. Took me about 6 hours start to finish, but I was not hard at it.
You will need a Harmonic balance wheel puller ($20) and a torque wrench. I was able to use the original oil pan gasket (front section seals the bottom of timing cover) as it was pristine. I did bead RTV sealant on all surfaces. I bought the upgraded Felpro gasket set with the repair sleeve for the Harmonic balancer and the oil seal.

I do suggest that the oil be changed before starting the engine as the oil pan is exposed below the assembly and I was scraping and cleaning surfaces.

Very happy with a normal sounding engine.

Monkiejohnson 10-16-2014 11:08 AM

Did you replace the tensioner as well?

TJ4Jim 10-16-2014 05:45 PM


Originally Posted by Monkiejohnson (Post 14095042)
Did you replace the tensioner as well?

Sorry I misunderstood. Yeah to get at those bolts the pan has to be dropped. I was able to reuse the bracket and just replace the rubber both times I did a replacement.

SilverTJMike 10-16-2014 10:42 PM

I have a write up on for the replacement on a 4.0liter as well. Do read the puller instructions so you don't mess up your crank threads... I found mine was stretched when I replaced the rear main seal (always a good time to check things).

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