Thanks for the greetings and thanks to all who are applying your thoughts, time and skills to resolving this OPDA Lubrication (Laughing Monkeys) issues on the 2005-06 4.0. I learned of this issue through the forums at about about 68000 miles. I pulled my OPDA and inspected it.
My findings were the same as many others out here. The gear worn as in other pictures, more than I'd like to see, the shaft spins freely, no permanent scoring. I immediately ordered new unit. Now I too am on the waiting list for a new unit since, December 2010. The price was $113.52 complete with OPDA gasket until last week when the OPDA became available for delivery. The new price is now $253.12. Anyone have a used one they want to sell me?
Some have mentioned routing oil to the upper and/or lower bushings. On that note, since early February 2011, I've been running an experimental oiler to lubricate my upper bushing with engine oil. It is loosely based on the FOGMod and so far seems to keep the top bushing, at least, well lubricated.
I chose to try oil rather than grease as a lubricant based the fact that it was used on some older point type distributors that required oil lubrication for the top bushing at regular service intervals, and based on my belief that, by design, the lower bushing was meant to be lubricated with engine oil. So I figured what's good for the lower should be good for the upper too. And I wanted to try something different. What do I have to lose?
My oiler consists of a remote (4-6 fl oz. of 1" pipe) oil reservoir, plumbed into the factory grease fitting/reservoir (1/8-npt), which allows oil to gravity feed through a freshly drilled hole (size Q bit) in upper bushing onto the OPDA shaft, above the factory oil seal. The system is unvented and sometimes a small amount of pressure is detected during post operation inspections, when removing the cap.
In my experience, it is correct that, provided the factory oil seal is intact, the oil climbs the OPDA shaft, and bypasses the top of the upper bushing spilling into the OPDA cup before it leaks past the factory seal below the upper bushing. To overcome this, I have completely sealed the OPDA cup against leakage with black RTV around the CPS sensor, over the threaded plugs added to the 2 holes in the bottom of the cup, and between the cap and the top of the cup.
During operation the cup is full of oil, all of the internals are completely submerged in oil (no codes yet) and the tone wheel is spinning in oil. The system loses 1-2 ounces of oil weekly (40miles/day @ 2200 rpm) internally, I think this must push past the factory seal. I can't find any signs of external leakage. I believe the spinning of the tone wheel in the oil may create some backpressure on the oil in the cup and push it past the seal when the engine is spun at higher rpms. I've noticed no drain down operating under 1500 rpm or while engine is not running.
My main concerns are:
(a.) External leaks causing a fire or other dangerous conditions.
(b.) Inernal leaks creating a crankcase overfull condition.
(c.) Excessive system oil loss due to (a.) and/or (b.)
I check for all 3 conditions daily. External leaks are repaired immediately or the system taken out of service until the leak is repaired. I check the oil levels in the system and the crankcase daily. If my crankcase becomes overfull to the point of concern. I can remove excess oil through the dipstick tube or change the oil and/filter and recheck. None of these have been an issue yet.
I have had no real issues in 4000 miles other than small leaks, which I fixed. Meanwhile my OPDA still spins daily, waiting for its replacement. I have pulled and rechecked once at about 1200 miles use due to tracking down external leaks and found no burning on the shaft.
No leaks for last 1800 miles.
I say try whatever you can think of even if it's different.