2005-2006 TJs: OPDA and other problems?

[UNLTD06]

As above you are going to have to do some detective work.

If you pull off the cap on the OPDA and just hit the key so it doesn't start does the OPDA spin? If the OPDA does spin, kick it around on the key again till the holes line up and you can pin it, although a better option is to set the timing at TDC and set the OPDA at 4 o'clock as per the manual - it's downloadable from this forum. Worth a read.

If the OPDA doesn't spin when you do this, it's as stated, cam gear or timing chain. Pull the OPDA and check the gears as your first option.

Draining the oil is a good idea also to see if theres any glitter in there.

Hope it goes well for you.

@Daz7 @JKP Thank you both for your input/tips. I already knew that the OPDA did not spin so I took it off and my suspicion was confirmed. The corresponding gear on the camshaft wasn't as bad as the OPDA but it is toast. I had already drained the oil and still have it and the filter. I will check both for particles.
I am somewhat hopeful that because the OPDA shaft "froze" before the gear detonated, it did not continue to turn the oil pump. Obviously my minimum is a new camshaft. I'm severely bummed but..... I've always been curious about pulling a motor.

 

[JKP]

At a minimum you'll need a new: cam, lifters, OPDA, timing set.

Unfortunately you have to pull the head to get the lifters in/out.

All the above can be done with the engine in the Jeep.

Check out the FSM under Resources for R&R procedures and for proper cam/lifter break in procedure.

Drop the oil pan to get the pieces out of it. You can also inspect the bearings by pulling a cap or two.

 

[UNLTD06]

An update on my OPDA ordeal....My time has been limited this year but I've been able to replace the camshaft, lifters and pushrods. As you might expect the remaining chunks of the gear teeth that were in the oil pan have been removed. This was all done with the engine still in place.
I've set the engine to TDC (compression on #1) and installed the new Crown OPDA but using the original timing sensor. I've got the flange at the end of the OPDA shaft seated in the "receiver" for the oil pump but am wondering about the positioning of the OPDA. I don't recall how it was positioned when removed. As long as the timing is correct, does it matter? Can anyone confirm that the position in the photo seems correct?
Many thanks again!

 

[g.hayduke]

Can't tell anything from that pic. Take the cover off. There are alignment holes in the disk and the housing that need to be aligned with #1 @ TDC.

 

[UNLTD06]

Thanks @g.hayduke I know that the holes are aligned because the plastic pin is still in place. I was told I could leave it in and it would just shear off when I start the engine the first time

 

[AjRagno]

Thanks @g.hayduke I know that the holes are aligned because the plastic pin is still in place. I was told I could leave it in and it would just shear off when I start the engine the first time

The OPDA should be clocked to about 4 o’clock when fully seated. When installing, it will rotate as the teeth engage. Take it out, rotate a bit and put it back in until it is closer to 4 o’clock.

Once you have the OPDA installed and the retainer bolt tight, it's not going to rotate so there is no point to leaving the alignment pin in after that.

 

[UNLTD06]

@AjRagno I agree with 4 o’clock because the retaining bolt was nearly impossible to reach when I removed it because of the “arm” of the OPDA. My concern is that the shaft now drops easily into the oil pump because of how the slot is aligned. Does it make sense to try to turn the oil pump manually before installing so that I can get closer to the 4 o’clock position?
Thanks for your insight!

 

[AjRagno]

@AjRagno I agree with 4 o’clock because the retaining bolt was nearly impossible to reach when I removed it because of the “arm” of the OPDA. My concern is that the shaft now drops easily into the oil pump because of how the slot is aligned. Does it make sense to try to turn the oil pump manually before installing so that I can get closer to the 4 o’clock position?
Thanks for your insight!

Yes, turn the oil pump. If you get P0016 after after it’s up and running, you can loosen the retaining bolt and slightly rotate the body to get it synched.

 

[TJADDICT84]

Are there any signs or symptoms of a failing or failed OPDA ?

 

[UNLTD06]

Are there any signs or symptoms of a failing or failed OPDA ?

People refer to it making a sound like “laughing monkeys”. I don’t know what a laughing monkey sounds like but I suspected the sound I heard was my serpentine belt squealing. It was very infrequent at first but then became more consistent. The volume increased over time as well. I was not driving it when it finally grenaded but my wife called it a loud bang.
I think I’m grateful I didn’t hear it

 

[Link]

I’d replace it. Pretty cheap insurance to install the Crown unit. I did it and it was a super easy job. I did use a marker to mark the old housing to the block. Pulled the old unit, laid it next to the new one, put a mark on the new one with a marker that matched the old one, then dropped it in. I did need to turn the oil pump a little with a long screw driver so it would drop in and align properly. Extremely easy job. Taking my time I was still done in 30 mins.

A distributor hold down tool makes it a lot easier to remove and tighten the bolt.

 

[Fishtaco]

Are there any signs or symptoms of a failing or failed OPDA ?

I also have no idea why they call it laughing monkeys? It can start as a short infrequent squeal sound like a wet serpentine belt as UNTD06 mentioned, if it fails it will stop spinning and chew up your cam so you will know it has failed. If you have an 05-06 and hear even a short squeal stop the engine and don't drive it until it is changed out! or if it hasn't been changed yet just change it asap would be my advise.
Seems the OPDA can get dry or not spin freely many times before it seizes up, this can be seen on early vids where people were not so aware and filmed the constant squeal while increasing the revs really high not realizing the damage it was doing.

You can hear a similar sound when some older cars pull away at traffic signals with their A/C on full blast.

 

[Zorba]

Sounds like laughing monkeys to me!

 

[rasband]

I also have no idea why they call it laughing monkeys? It can start as a short infrequent squeal sound like a wet serpentine belt as UNTD06 mentioned, if it fails it will stop spinning and chew up your cam so you will know it has failed.

Mine was a ticking. I had to feel/listen around and look a bit to figure out what it was when I needed to swap mine.

 

[AjRagno]

Are there any signs or symptoms of a failing or failed OPDA ?

When my original OPDA failed it was making a ratcheting sound but only as RPMs dropped on deceleration or after revving the engine. The replacement Dorman OPDA only lasted a few months before it started making a tapping to ticking sound when cold. After that I went with Crown and have not had any further issues in the 86,000 miles since.

 

[Link]

Sounds like laughing monkeys to me!

Wow mine didn’t sound anything like that! But then it wasn’t really making any sound at all. I thought I heard a ticking sound before it replaced it. I replaced it as preventative maintenance. Glad I did.

 

[sorias]

The OPDA seems to be the biggest issue. Yours is a manual transmission. With the automatics, the PCM (engine and trans brain), seems to be an issue too. Finding replacements for those are hard to find. I would not assume that OPDA is okay. But, take a few pictures of it and post them here. Someone should be able to tell you if it's been replaced. It is that round thing on the right side of the engine, with a black plastic top. If you have any doubts, replace it. It's only about 130-150 euros or so and cheap insurance. The recommended brand is crown but use the original sensor from yours and put it in the new one.

Could you. Start the jeep, hear the squeal. Stop the jeep, remove the drive belt. Restart the jeep, and if the squeal has gone, would that confirm its not the OPDA, or harmonic balancer......?