What is the OPDA and do I need to change mine?

jeep2fun

Member
Joined
Nov 23, 2020
Messages
66
Location
Denver, CO
OMG what a relief- now I can return the OPDA I purchased from NAPA. I love the learning here. Will keep looking.
@Chris , please provide any inputs on the below. Does a bad power distribution plate stall the vehicle?

 
OP
Chris

Chris

Administrator
Staff Member
Ride of the Month Winner
Joined
Sep 28, 2015
Messages
68,772
Location
Florence, AZ
@Chris , please provide any inputs on the below. Does a bad power distribution plate stall the vehicle?

Unfortunately I can’t comment on that as I’m not sure myself.
 

hobnob

New Member
Supporting Member
Joined
May 4, 2020
Messages
3
Location
Nairobi, Kenya
Hi all, I have a camshaft synchroniser that's clicking on a 2003 Wrangler 4.0. Do you recommend to just replace the synchroniser as it is or change to the OPDA version that much bigger (I understand from the forum here that it was used from 2005 onwards). Is that upgrade worth it? And it will fit despite the much larger size?

RenderedImage.JPG
 

MaximusLJR06

Jeep Green LJR Addiction
Supporting Member
Joined
Aug 12, 2020
Messages
510
Location
York, PA
Hi all, I have a camshaft synchroniser that's clicking on a 2003 Wrangler 4.0. Do you recommend to just replace the synchroniser as it is or change to the OPDA version that much bigger (I understand from the forum here that it was used from 2005 onwards). Is that upgrade worth it? And it will fit despite the much larger size?

View attachment 296069
The 05/06 version will not work on your motor. Stick with the camshaft synchronizer for an 03
 
  • Like
Reactions: hobnob
Joined
Jul 30, 2019
Messages
45
Location
Fairfax, Va
Figured I'd add my experience to this thread for future OPDA installs. I have a very late build date LJ (06/2006) with a rev. E factory OPDA. Never had any issues with it (currently at 170k), but after reading that the OPDA gear was hardened steel on the OEM unit, I decided to change mine out to limit cam gear wear. There was significant wear on both the OPDA gear as well as the cam, but not enough to warrant replacing the cam. Crown unit went in without any issues, but the housing itself is oriented 90 degrees off from where the factory one was (the cover bolts now are perpendicular to the block instead of parallel). I tried fiddling with it for awhile, but I'm assuming this is due to the oil pump driver (looks like a flat head screwdriver) being in a different orientation on the Crown unit. I made sure the sensor was in the same orientation to the internal wheel of the new OPDA and removed the plastic pin before install. I then replaced the plastic pin with a thin dowel (inserted from the top, OPDA cover off). You can also use a screwdriver of the proper diameter. Dowel just stays in until the unit is properly secured into the engine block, then remove dowel, replace cover. I didn't like the idea of letting the crown plastic pin break off and stay inside the OPDA as most videos suggest. Take note here: If you visually use the factory OPDA to find TDC, there are two holes in it. One has a sleeve (or collar) going vertically inside the OPDA housing, one doesn't. The one with the collar is the factory TDC orientation hole and is what lines up with the location of the Crown plastic retaining dowel in the new unit. This is the hole you want to line up with the OPDA timing wheel hole in the old OPDA before you install the Crown. If you use the wrong hole, you'll have a bad day (insert jokes here)- it will cause the timing to be off. Reuse the mopar sensor and save the new crown sensor as a spare. Do not, under any circumstance, turn the camshaft pully or crank the motor with the OPDA removed. If you can't get the new OPDA lined up, you can use a long flathead to turn the oil pump driver inside the block (look inside hole the OPDA was removed from) enough to get things to line up.
 
  • Like
Reactions: NOTNSUV

NOTNSUV

Now I Know!
Supporting Member
Joined
Sep 18, 2021
Messages
1,462
Location
Spring Creek, NV
Figured I'd add my experience to this thread for future OPDA installs. I have a very late build date LJ (06/2006) with a rev. E factory OPDA. Never had any issues with it (currently at 170k), but after reading that the OPDA gear was hardened steel on the OEM unit, I decided to change mine out to limit cam gear wear. There was significant wear on both the OPDA gear as well as the cam, but not enough to warrant replacing the cam. Crown unit went in without any issues, but the housing itself is oriented 90 degrees off from where the factory one was (the cover bolts now are perpendicular to the block instead of parallel). I tried fiddling with it for awhile, but I'm assuming this is due to the oil pump driver (looks like a flat head screwdriver) being in a different orientation on the Crown unit. I made sure the sensor was in the same orientation to the internal wheel of the new OPDA and removed the plastic pin before install. I then replaced the plastic pin with a thin dowel (inserted from the top, OPDA cover off). You can also use a screwdriver of the proper diameter. Dowel just stays in until the unit is properly secured into the engine block, then remove dowel, replace cover. I didn't like the idea of letting the crown plastic pin break off and stay inside the OPDA as most videos suggest. Take note here: If you visually use the factory OPDA to find TDC, there are two holes in it. One has a sleeve (or collar) going vertically inside the OPDA housing, one doesn't. The one with the collar is the factory TDC orientation hole and is what lines up with the location of the Crown plastic retaining dowel in the new unit. This is the hole you want to line up with the OPDA timing wheel hole in the old OPDA before you install the Crown. If you use the wrong hole, you'll have a bad day (insert jokes here)- it will cause the timing to be off. Reuse the mopar sensor and save the new crown sensor as a spare. Do not, under any circumstance, turn the camshaft pully or crank the motor with the OPDA removed. If you can't get the new OPDA lined up, you can use a long flathead to turn the oil pump driver inside the block (look inside hole the OPDA was removed from) enough to get things to line up.
Did you have someone to watch timing marks on the crank pulley while you rotate the OPDA and give a shout when you hit TDC?
, did you pull #1 plug and check TDC?
And is it obvious when it's on the compression stroke?

I've seen some videos and your explanation is good, just wondering about the first couple steps before pulling the old OPDA.

Thanks.
 
Joined
Jul 30, 2019
Messages
45
Location
Fairfax, Va
Did you have someone to watch timing marks on the crank pulley while you rotate the OPDA and give a shout when you hit TDC?
, did you pull #1 plug and check TDC?
And is it obvious when it's on the compression stroke?

I've seen some videos and your explanation is good, just wondering about the first couple steps before pulling the old OPDA.

Thanks.
No, I exclusively used the factory OPDA holes and did it by myself. I removed the OEM OPDA plastic cover and I turned the camshaft pully (19mm socket, clockwise, in neutral, preferably with a very long handled ratchet or small breaker bar) until the alignment holes in the factory OPDA lined up, indicating TDC. If you are on the wrong stroke, the alignment holes in the OPDA will be 180 degrees off (opposite sides of the housing. This was suggested on a few videos, as the timing marks on the pulley can be hard to see. I did not pull spark plugs. What's most important here is that the timing wheel marks inside the new OPDA are in the exact same orientation to the cam sensor as they were in the old OPDA. AFAIK the orientation of the oil pump drive itself does not matter (the flathead part, not to be confused with the OPDA spider gears). The reason you put it at TDC is so that the alignment holes in the OPDA can be utilized, preventing it from turning when you install it. You'll notice that the housing rotates some to clear the spider gears on the cam shaft, but the dowel prevents the timing from being altered. Just make sure you always have the alignment holes locked together with a dowel on the new opda and you'll be fine. There will be some play, but not enough to cause a problem. The internet makes it sound a lot harder than it is. Good luck!
 
  • Like
Reactions: Zorba and NOTNSUV

Zorba

"The Veiled Male"
Supporting Member
Joined
Apr 2, 2020
Messages
9,955
Location
Merritt Island, Fl
No, I exclusively used the factory OPDA holes and did it by myself. I removed the OEM OPDA plastic cover and I turned the camshaft pully (19mm socket, clockwise, in neutral, preferably with a very long handled ratchet or small breaker bar) until the alignment holes in the factory OPDA lined up, indicating TDC. If you are on the wrong stroke, the alignment holes in the OPDA will be 180 degrees off (opposite sides of the housing. This was suggested on a few videos, as the timing marks on the pulley can be hard to see. I did not pull spark plugs. What's most important here is that the timing wheel marks inside the new OPDA are in the exact same orientation to the cam sensor as they were in the old OPDA. AFAIK the orientation of the oil pump drive itself does not matter (the flathead part, not to be confused with the OPDA spider gears). The reason you put it at TDC is so that the alignment holes in the OPDA can be utilized, preventing it from turning when you install it. You'll notice that the housing rotates some to clear the spider gears on the cam shaft, but the dowel prevents the timing from being altered. Just make sure you always have the alignment holes locked together with a dowel on the new opda and you'll be fine. There will be some play, but not enough to cause a problem. The internet makes it sound a lot harder than it is. Good luck!
^^^THIS^^^

Exactly the way I did it.
 

pagrey

TJ Guru
Supporting Member
Joined
Apr 10, 2018
Messages
7,726
Location
Los Angeles, CA, USA
If you just take a careful photo of the sensor wheel before you remove the OPDA the position marks or just about anything else doesn't matter. You don't even need the plastic deal, you'll get it pretty close if you just match where it starts. Obviously this is the 2004 but the idea is the same.

opda.jpg


If you match the position of the rotor and housing exactly it'll be pretty close. You are only screwed if the engine rotates. You have to watch the rotor carefully as you pull it so you know what angle to start the new one so you don't skip a tooth on the gear. I've had my OPDA out several times and only used the scan tool to adjust it when I replaced the sensor because I figured that's the only time it might have changed a bit. If you replace the sensor itself they all have different slew rates so it's a crap shoot if it's going to match regardless of where you set it. That's probably why the standard instructions in the service manual suggest using the tool after replacement to sync it.
 

Kyra913

New Member
Joined
May 15, 2017
Messages
4
Location
Overland Park, KS, United States
I have an 06 LJR, the OPDA went out and blew the engine, replaced the engine and OPDA with a Crown. I have had to replace the OPDA every year since; it goes into "limp mode" and then won't start right away and gives me the P0344 & P0340 codes. What I have learned in the past 4 years since the engine replacement is that it's not the OPDA itself it's been the sensor which you can't purchase individually. I have heard that you should keep the original sensor and only replace the OPDA itself, to little too late for me on that one though. I still don't feel like I should be having to replace the sensor that often or what causes the issue, if anyone has insight into this I would love to hear it.
 
  • Like
Reactions: imahnu

imahnu

Unorthodox
Supporting Member
Joined
Jun 1, 2021
Messages
278
Location
Houston, TX
I have an 06 LJR, the OPDA went out and blew the engine, replaced the engine and OPDA with a Crown. I have had to replace the OPDA every year since; it goes into "limp mode" and then won't start right away and gives me the P0344 & P0340 codes. What I have learned in the past 4 years since the engine replacement is that it's not the OPDA itself it's been the sensor which you can't purchase individually. I have heard that you should keep the original sensor and only replace the OPDA itself, to little too late for me on that one though. I still don't feel like I should be having to replace the sensor that often or what causes the issue, if anyone has insight into this I would love to hear it.
For those of us that have thrown away or lost our OEM sensors, the standard suggestion is to try the NAPA sensor which shows some good results. For myself I’ve used a crown OPDA with an AIP electronics sensor (available on Amazon) for roughly 4 years and 50k miles without issue.

Only use the crown OPDA
 

Nutro

New Member
Supporting Member
Joined
Jun 15, 2022
Messages
14
Location
Austin, TX
I just bought an 06 LJ and want to replace the ODPA ahead of time but paranoid I will screw it up. I bought the Crown unit and will start looking for a shop that can do it
 

JMT

Saxum Erepo 🪨
Supporting Member
Ride of the Month Winner
Joined
Feb 27, 2017
Messages
19,021
Location
🌎
I just bought an 06 LJ and want to replace the ODPA ahead of time but paranoid I will screw it up. I bought the Crown unit and will start looking for a shop that can do it

It’s really not difficult, even if you lose TDC.

Make sure and re-use the OEM sensor!!!
 
  • Like
Reactions: Charlie L and Zorba

Rickwhoo

TJ Enthusiast
Joined
Jun 24, 2021
Messages
116
Location
Moscow PA USA
Mine started making noise today. I can feel the scraping on the cover too. It looks exactly the same as replacing a distributer. Is there any adjustments when I replace it? Does it turn like a distributer?