Should I replace my OPDA if it works?

Peter Panagakos

TJ Enthusiast
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Oct 3, 2017
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214
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Rio Rancho, NM, United States
I have a 2006 pretty much stock TJ. It has the 4.0 engine and the factory OPDA. I put the Wrangler Fix PCM in about a year ago to fix hard shifting auto trans. I have had no other issues, runs fine. I have 132,000 miles and the factory OPDA. I listened to it with a stethascope, no odd noises, and no error codes. I have a crown OPDA as a backup. I read all the posts about this , but still not sure I should replace if it works ok. I would like some advise on this. I had a 2006 Rubicon years ago and did have to replace the OPDA on that as it started to shreek. I have a friend who replaced his three times and finally had to replace the cam, but most don't ever have the problem. Seems like everyone should have the OPDA problem if it's as bad as it sounds on the internet. Advise?
 
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I replaced mine in my 06 around 118k. It worked fine and had no issues. Alternatively, my father was driving his 05 on a road trip when his went out without warning. His Jeep had about 125k on it. It wasn't an easy part to get in the middle of nowhere. I always prefer to perform preventive maintenance when I can.
 
I would inspect it first and replace it based on how the gear looks. It’s a wear-and-tear part like anything else so in all reality replacing it even if it isn’t bad isn’t a such terrible idea.
 
I have a 2006 pretty much stock TJ. It has the 4.0 engine and the factory OPDA. I put the Wrangler Fix PCM in about a year ago to fix hard shifting auto trans. I have had no other issues, runs fine. I have 132,000 miles and the factory OPDA. I listened to it with a stethascope, no odd noises, and no error codes. I have a crown OPDA as a backup. I read all the posts about this , but still not sure I should replace if it works ok. I would like some advise on this. I had a 2006 Rubicon years ago and did have to replace the OPDA on that as it started to shreek. I have a friend who replaced his three times and finally had to replace the cam, but most don't ever have the problem. Seems like everyone should have the OPDA problem if it's as bad as it sounds on the internet. Advise?

I too have a 2006 unlimited Rubicon, replaced OPDA at 144,*** miles had what I considered a new unusual sound and after replacement sound is gone. The irony is even with the new OPDA you still have to beware of the condition may reappear. My advice is to continue to enjoy your Jeep you seem to be prepared and know your Jeep so you can quickly replace your OPDA when that time comes. The old saying if it ain’t broke don’t fix it or if replacing the OPDA gives you that peace then by all means do it, just a reminder reuse original sensor.
 
I'm at 150K with one on the shelf also.
Been debating what to do lately, because I have an extra long road trip coming up this summer.
Afraid pulling it just to check might change how it runs.
 
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Evidently there are quite a few of us with a Crown OPDA on the shelf. Some people have no problems replacing it, and some have a terrible time getting it set correctly, no matter how careful they are. Mine's on the shelf because I don't know which side of the coin flip I'll get. If I knew someone with a DRB III . . .
 
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I replaced mine in my 2005 at 163k. It had the OE OPDA in it but I have no idea if it had been replaced at some point in the past. It wasn't making the squealing noise but I decided to replace it anyway with the Crown unit. The gear looked good but when I replaced it, the new one had less rotational play once installed than the old one. I'm glad I replaced it.

Here's what I did. It's an easy replacement. Set the #1 cylinder at TDC. Using a sharpie marker draw a straight line on the OPDA and onto the engine block. Remove the cap from the OPDA and make sure the alignment holes line up. Insert the plastic alignment pin from the new one into the old one. Remove the OPDA hold down bolt. Lift out the OPDA....you'll have to rotate it a little as you pull it out. Lay the old one next to the new one. Draw a matching line on the new one in the same position as the old one. Make sure the new gasket is on the new OPDA. Put the alignment pin back in the new one and put it in the engine. You'll probably have to use a large screw driver to rotate the oil pump drive shaft a couple times till you get it aligned and it drops in. It'll turn a little as it drops in. If your sharpie lines don't line up, lift it back out, rotate the whole OPDA a small amount and drop it back in. You'll probably have to pull it out, rotate the oil pump, rotate the OPDA a little, and drop it back in a couple times till it all lines up. If it doesn't drop in all the way, you need to rotate your oil pump drive shaft. As long as you don't rotate the crankshaft you'll be fine to lift it out and drop it back in however many times you need to. Once it all lines up, tighten down the hold down bolt, remove the plastic locking pin, and reinstall the cover. As mentioned, reuse the original camshaft sensor.

Extremely easy. I took my time and was very methodical and still only took me 30 mins.
 
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My 06 LJ developed a squeal when I used it during a Thanksgiving elk hunt on early morning startups. Usually 20 degrees or lower. Only squealed for a few seconds. I didn't know about the OPDA problem, so assumed it was related to the serpentine belt. Been stored since then. I will be back in Colorado next week and plan to drive it. It sits in garage that never gets under mid 40's, so I'll see if it squeals. If so, I plan to start with idler pulley, tensioner, and belt. If I suspect OPDA I will do replacement. Has 106K miles. Runs great.
My question to LInk is, how do you make sure #1 cylinder is TDC and how to do use screwdriver to rotate oil pump.
 
I did this job before and it is not difficult if you are careful. First, I took the plastic cap off the OE OPDA so I could see where the holes for the pin that comes with the new Crown unit are. They need to line up so you can put in the pin. Note that the crankshaft will turn two times for one revolution of the OPDA. Turn the Crank clockwise with a socket and ratchet (transmission in nuetral) until the crank mark lines up with the timing marks on the timing cover at TDC. I know this part is a pain, but necessary. Now see if the pin holes in the OPDA are lined up. If they are 180 degrees off you are on the exhaust stroke. Rotate the crank until the timing marks are lined up and hopefully the pin holes in the OPDA will be lined up as well. Put the pin in the old OPDA and make marks on the OPDA and the engine block so you can line up the new OPDA. Put the same mark on the new one and you should be able to put the pin back in the new one and line it up in the same place as the old one. Everyone says to take the OEM camshaft sensor out of your old OPDA and put it in the new one as the OEM sensor works better. Hope I didn't over explain this. If everything lines up right, you should not have a problem.
 
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My 06 LJ developed a squeal when I used it during a Thanksgiving elk hunt on early morning startups. Usually 20 degrees or lower. Only squealed for a few seconds. I didn't know about the OPDA problem, so assumed it was related to the serpentine belt. Been stored since then. I will be back in Colorado next week and plan to drive it. It sits in garage that never gets under mid 40's, so I'll see if it squeals. If so, I plan to start with idler pulley, tensioner, and belt. If I suspect OPDA I will do replacement. Has 106K miles. Runs great.
My question to LInk is, how do you make sure #1 cylinder is TDC and how to do use screwdriver to rotate oil pump.


Easiest way.....put a ratchet with correct size socket on the crankshaft pulley bolt. I can't remember the size....19mm maybe? Turn the crankshaft till the timing mark aligns with the TDC mark. It's hard to see but can be done from under the vehicle with a bright flashlight. A mirror might make it easier as well. As long as your harmonic balancer is in good shape and hasn't slipped, you'll be at TDC on the compression stroke. Remove the cap from the top of the OPDA and the alignment holes should be in alignment. If they are off, your harmonic balancer may be off and if so, you'll have to do it the harder way. Remove the #1 spark plug and drop a longer dowel type rod into the cylinder. Turn the crankshaft till it clearly is at TDC and look at the OPDA. Are the holes lined up? If not, then you're at the top of the exhaust stroke and need to turn the crankshaft to bring it into TDC on the compression stroke again.

As far as the screwdriver to rotate the oil pump drive.....it's super simple. Look at the end of the OPDA where it goes in the engine. It kind of looks like a big screwdriver. That's what you are turning with a flat head screwdriver to rotate it. I would rotate it 1/8-1/4 turn at a time till it all lines up. The oil pump isn't timed like the OPDA to the cam is so the OPDA "screwdriver" just needs to smoothly mesh with the oil pump.

Don't let it intimidate you. If you do it this way, it'll line up perfectly and work properly.

The best way to loosen the hold down bolt is with an old school distributor tool. If you don't have one, a wrench will work but be a little more difficult to access.

The sharpie line on the two units will just help you ensure it's in the exact right spot.
 
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I replaced mine at about 55,000mi. The original looked fine, so I kept it for backup. Install went fine except I forgot to use the gasket between the OPDA and the block. When I removed it to put the gasket on I had to go through the process of finding TDC. It wasn’t horrible, but it was pain that could have been avoided.
 
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Easiest way.....put a ratchet with correct size socket on the crankshaft pulley bolt. I can't remember the size....19mm maybe? Turn the crankshaft till the timing mark aligns with the TDC mark. It's hard to see but can be done from under the vehicle with a bright flashlight. A mirror might make it easier as well. As long as your harmonic balancer is in good shape and hasn't slipped, you'll be at TDC on the compression stroke. Remove the cap from the top of the OPDA and the alignment holes should be in alignment. If they are off, your harmonic balancer may be off and if so, you'll have to do it the harder way. Remove the #1 spark plug and drop a longer dowel type rod into the cylinder. Turn the crankshaft till it clearly is at TDC and look at the OPDA. Are the holes lined up? If not, then you're at the top of the exhaust stroke and need to turn the crankshaft to bring it into TDC on the compression stroke again.

As far as the screwdriver to rotate the oil pump drive.....it's super simple. Look at the end of the OPDA where it goes in the engine. It kind of looks like a big screwdriver. That's what you are turning with a flat head screwdriver to rotate it. I would rotate it 1/8-1/4 turn at a time till it all lines up. The oil pump isn't timed like the OPDA to the cam is so the OPDA "screwdriver" just needs to smoothly mesh with the oil pump.

Don't let it intimidate you. If you do it this way, it'll line up perfectly and work properly.

The best way to loosen the hold down bolt is with an old school distributor tool. If you don't have one, a wrench will work but be a little more difficult to access.

The sharpie line on the two units will just help you ensure it's in the exact right spot.

Thanks for the detailed instructions.
 
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You guys are overthinking this. Its cheap insurance. I replaced mine at 129K. Its super easy IF you take your time and pay attention to what you're doing. If it helps, here's my blow-by-blow account:

https://www.doubleveil.net/jeep/twenty-eight.htm

I marked your OPDA replacement page and between it and Link's instructions I feel confident this will go smoothly if I need to replace it. If I don't do it next week, I will when I go up for the summer for sure. Thanks
 
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I marked your OPDA replacement page and between it and Link's instructions I feel confident this will go smoothly if I need to replace it. If I don't do it next week, I will when I go up for the summer for sure. Thanks

Watch a few yootoob vids as well. None of them were "complete" enough for my comfort level, but if you watch a few, you'll get a good feel for the job.
 
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Anyone around Indiana want to help me with mine? 😁

I've watched all the videos and read quite a bit....still not totally confident in myself.
 
I think all of you helped me make my mind up. To see if my original factory one is ok, I need to pull it and check the gear. As long as the cam shaft gear looks good and the old one is out, might just a well put in the Crown unit. Knowing my compulsive nature I wouldn't be able to stop at that point. I'll remember to use the original cam sensor. Thanks.
 
I replaced mine at 100k. For me the job went very smoothly and I had no difficulty. The trouble with keeping one on the shelf is that by the time you decide to replace it because you hear noise, the cam shaft may already be toast and now you have a much larger problem.
 
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Now that I decided to go ahead with replacing, is it best to remove the OEM cam sensor before taking the OPDA out of the engine or after. Seems like before would make more sense to avoid damage to it and make access to the hold down clamp a bit easier. As I recall, when I did this job before on my 2006 Rubicon, I took it out after, but that was years ago and my memory is not all that great. I also managed to strip one of the OPDA plastic cap screws because of those damn star tools or whatever they are called. Now I need to remove it a different way. Bolt extractor I guess.