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So, I'm in the middle of reassembling my own oil pump on a new-to-me project truck. I am therefore following this sad tale with great interest. I didn't see anywhere in the D2 workshop manual, the RAVE, or the 4.0/4.6 engine overhaul manual about there being a specific orientation for the drive gear in the middle of the oil pump. Like the OP, I believe that the chamfers on the gear are the same in both directions so there is no "top" and "bottom" face to that assembly. Of the three complete oil pumps in my possession (the original one from this truck, plus two replacements that I purchased) one of them has a small index mark stamped into the outer pump ring, but there doesn't seem to be anything to align it with.
I have already reassembled and reinstalled the entire front cover, oil pickup and oil pan but I'm waiting on a head gasket kit so I haven't tried to run the engine yet. I was planning to run it through a few rotations using a wrench on the harmonic balancer to check that everything is turning smoothly. But now that I'm terrified by the photos above and before I tear everything apart again to check it, can anyone provide specific alignment and/or orientation instructions (for me and the OP) to follow?
I was thinking before I put the balancer on that I would put a wrench on the crank bolt as well to see if everything is moving well also. Wondering if that is enough for a bit of peace of mind
It didn't make sense to me to put the only bolt on to turn the engine without putting the balancer/pulley on as well. If all is good, you'd have to undo the bolt in order to put the balancer on. If the balancer is already on there, you just have to tighten the bolt to torque.
I did turn the engine several times using just the bolt after I installed a new timing chain and sprockets, before putting the front cover on. I'm pretty sure you'd be able to feel any binding, tight spots, or disaster points through the wrench. It can't hurt to do it just to make sure the rotating assembly, well, rotates.
So I'm looking closely at your carnage pics and few things stand out to me.
The amount of Vaseline still present (especially still pack in the oil pickup location) seems to indicate that oil may have never even gotten to the pump. I would think the Vaseline would immediately start moving through the system once started and it sure doesnt look like oil ever mixed in with the Vaseline (look at all the fresh Vaseline still packed where the oil inlet is!)
If your truck ran for minutes with no oil getting to the pump, it would quickly heat up the gears and they would eventually seize up just like in your pics, and then exploded. So I might have to change my original opinion that Vaseline couldn't possible be packed in to tightly. The evidence does seem to support that case, in my opinion.
I think the failure point may have been a clogged oil inlet, just my opinion.
I agree, I would check the pickup tube into the cover.
Was there sludge in the oil pan when you took it off originally?
If the woodruff key wasn't lined up correctly, would he even be able to sit the front cover flush against the gasket and mount it without it being overly obvious something was off? Not to mention the oil pan probably wouldn't line up if the front cover was off, I would think anyway
Just spit-balling balling about this sad tale but the gears in the earlier pictures are not in pieces, and I am SHOCKED at the sight of the cover plate and screws. Why would the gears be pushing on that plate????
I think the answer is the bevel on the inner gear. It shouldn't face the woodruff key.
I'm not sure where the Vaseline would have gone other than the cavity where it is in the pictures, assuming no oil was being sucked in.
Double checked mine after buttoning up the oil pan woodruff key is at 1 o'clock. Rotated a few tines and seemed smooth. So nervous now about my first start lol.
So looking closer at this picture has me asking, "Now just what in the hell caused these deep circular cuts in the gear cover"? Does your crank have damage?
It sure does seem like something was torqued up against that cover. That would explain the cover bolts all torqued sideways like that.
I agree, I would check the pickup tube into the cover.
Was there sludge in the oil pan when you took it off originally?
Originally Posted by R0VERGUY
So I'm looking closely at your carnage pics and few things stand out to me.
The amount of Vaseline still present (especially still pack in the oil pickup location) seems to indicate that oil may have never even gotten to the pump. I would think the Vaseline would immediately start moving through the system once started and it sure doesnt look like oil ever mixed in with the Vaseline (look at all the fresh Vaseline still packed where the oil inlet is!)
If your truck ran for minutes with no oil getting to the pump, it would quickly heat up the gears and they would eventually seize up just like in your pics, and then exploded. So I might have to change my original opinion that Vaseline couldn't possible be packed in to tightly. The evidence does seem to support that case, in my opinion.
I think the failure point may have been a clogged oil inlet, just my opinion.
You may be on to something there. The Pick up tube itself was free and clear, but I did not inspect that point. I am in Japan until early next week to watch Formula1(woohoo!) and will take a peek in there to be sure
The oil pump DID spin free. On disassembly I removed the crank pulley, put the bolt back in and turned the engine by hand while watching the pump gear(you can see it clearly through the front opening with the pulley off) and the pump was rotating as normal before the cover came off, so again, woodruff key was absolutely in the drive gear right, as well as the crank pulley. There really isn't a way to actually put it together without it being keyed right... The pieces simply would not fit together.
No oil made it into the pump, for sure. So failure happened on assembly/ very first start
I'll be sure to check that pick up next week
Follow up question though, can anyone confirm if there is a correct in/out forward/back orientation of the pump gears? The only one with any tangible manufacturing difference is the outermost gear. One face has a very small bevel on the outermost edge. The pump housing does NOT appear to have a corresponding bevel to match to, but you never know. The innermost gear bevel exists on both sides of the gear so that does not appear to be "sided"
