Thread: Roger's LARS Mis-Adventure 2014

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August, I'd say that caption is wrong. I'd say the seized oil pump caused the twisted shaft, not that the twisted shaft seized the pump.

Roger, when you pulled the pump apart, did you see any debris or small pieces of metal in between the gears in the pump? I've seen small pieces of metal get in the pump in between the teeth causing them to lock up. I've even seen them get on the top or bottom of the gears, create gauling, and seize the pump. The pump definitely killed the shaft.

I'll admit to never seeing one that bad! What I find equally amazing is the pin on the distributor gear never sheared.. or did it?

Hmmm, I'll be interested in how this plays out for a solution. I just acquired a fresh 302 so don't want to experience this.

No debris in the pump, Roger? Or anything between the gears and the housing? Based on a quick Google, you're not alone. All the stories seem to be about Fords, though.

Originally Posted by 40FordDeluxe

Roger, when you pulled the pump apart, did you see any debris or small pieces of metal in between the gears in the pump? I've seen small pieces of metal get in the pump in between the teeth causing them to lock up. I've even seen them get on the top or bottom of the gears, create gauling, and seize the pump. The pump definitely killed the shaft.

Ryan,
I'm embarrassed to tell the story of the pump, but I will anyway. I couldn't turn the pump with the shaft, even with a pair of pliers so I pulled the cover. The pump elements seemed to be "stuck", but when I turned it over to look at the top side they fell out into a bucket that had some drained oil in it so I cannot say for sure that there was nothing in the pump body. With the pump elements back in the body the pump turns freely, but when I put the cover back in place it gets snug, with the bolts hand tight the pump can be rotated only with pliers on the shaft, and if the bolts are torqued the pump is locked.

I took the pump back apart and noticed a small "dent" on the bottom of the body, seen middle right in this picture:

DSC00789.JPG

Looking at the rotating element there's a corresponding "dent", seen at the bottom of the picture:

DSC00795.JPG

It looks like maybe something got in between the two pieces and jammed them. What I cannot figure is how something got past the screen in the pickup?

Originally Posted by 34_40

I'll admit to never seeing one that bad! What I find equally amazing is the pin on the distributor gear never sheared.. or did it?

No, the roll pin on the distributor gear is straight and true, and I admit I'm baffled by that, too.

What really has me baffled is where the stuff I found in the pan came from. The biggest baffler is the small machined "spacer" that's 0.039" OD, 0.029" ID and 0.008" thick. My first thought was that it came from the earlier rocker arm failure, where one roller tip came out and a second rocker fractured into two pieces, but there's nothing like this "spacer" on the old rockers. I don't recall such a piece in the build history. There's also what might be a roller out of a bearing, and two small pieces of wire which measure 0.0032" or very close to it, which is a common safety wire size. Here's the junk, and it's all strongly magnetic -

DSC00787.JPG

The bigger "stuff" couldn't possibly pass the screen, and I don't believe that the small diameter wire could either. I can't see something getting into the engine and managing to work into the pump discharge side, and into the elements "backwards". It's a real head scratcher for me 1) where the junk came from, and 2) how something got into the pump.

Roger, looking around, I found this on a Jalopy Journal post. This came from post #27.

The oil pump pickup screen has a strap across the middle. Sometime when you find an old screen laying around, take snips and cut the strap on one side and pry up the strap. Under the strap you'll see a hole in the screen, usually finished with a stamped ring around the hole that is meant to seal against the backside of the strap. The intent is that if the screen gets clogged with sludge suction will pull the screen up and allow oil to get to the pump thru the hole.
Get that engine in a high rpm situation (maybe a kickdown to a lower gear in a passing mode, etc.)with a partially blocked screen and it will pull the screen up and any debris present (chunks of valve stem seals) will get sucked into the pump. Then what we see here happens, although I've never seen one twist so symetrically. Learned long ago when touring salvage yards in search of a rebuildable SBF core that the next thing to check after visible damage or missing parts was to pull the distributor and check the oil pump drive shaft.

My 1000-Mile Melling Oil Pump | The H.A.M.B.

BTW, was that a high-volume oil pump?

Have you cut the oil filter apart? Might be telling!

Originally Posted by Henry Rifle

...BTW, was that a high-volume oil pump?

Jack, very interesting read about the pickup, and as I read it I was thinking that I remembered seeing/reading about the bypass feature before but had totally forgotten about it. Thanks for taking time to find & post that info, and no it is an OEM replacement Melling pump.

Originally Posted by 34_40

Have you cut the oil filter apart? Might be telling!

Yes Mike, I did cut the filter apart and it had absolutely nothing in it. I pried off the top and bottom retainers and unfolded the accordion fold and found nothing but dirty paper.

I'll be talking to Scot Sehr this morning to see what he recommends that I do at this point. I'll play with the oil pump a bit more, too, to try to figure out why it's binding when the bolts are tightened. The whole thing is a head scratcher for me.

That's a good thing I feel (nothing in filter) "it" stayed in the pump.

I'll be curious what Scott says.

Originally Posted by 34_40

That's a good thing I feel (nothing in filter) "it" stayed in the pump.

I'll be curious what Scott says.

I had sent Scott the pictures late yesterday and he spent time looking & thinking before calling it a day. Neither of us can think where in the world that "spacer" came from, nor can we identify a source for the other little pieces of wire & rod. In the history, I brought the engine home without intake, distributor and pan but wrapped in plastic. Once home I installed the pan, but the engine did sit without the intake for some amount of time with the ports & distributor hole taped. Once installed in the painted chassis the distributor went in, the intake went on, and neither have been off again for 9600 miles. Nothing is safety wired on/in the engine, and no safety wire was done anywhere near the engine that I recall. Whatever got inside has been there since mid-2010, best I can tell.
Scott thinks that something got past the pickup bypass and bound up the pump causing a sudden stoppage that likely bent the shaft on the inner rotating element slightly. That would explain why it binds against the cover. The sudden stop also put the spiral in the shaft until it failed, but the shear pin survived without any deflection. Based on the fact that there is no metal in the filter, and no metallic residue in the pan we both think that the bearings are very likely OK, so the plan is to get a new pump, new shaft, some gaskets and after a good cleaning button it together, say a prayer and fire it up with an ear tuned.
Just to satisfy my curiosity I'm going to try to get a dial indicator on the oil pump elements and see if they are indeed "tweaked". There should be only .002 to .003" clearance between the elements and the cover, so any deflection is too much. We'll see, wish me luck!!

Well, if ya hurry, you can bolt it back together and still catch up with the other guys by tomorrow night.......

Originally Posted by rspears

August, I'd say that caption is wrong. I'd say the seized oil pump caused the twisted shaft, not that the twisted shaft seized the pump.

Correct, image is a good side by side of the before and after...

Mr. Spears... just grasping for a straw here... inspect the lifters (tops) while the intake is off. Probably all is well but,the "stuff" had to come from somewhere!

And purely as a PM task, I'd replace the dizzy drive gear pin. It's taken a nasty hit imho... needs to be changed. fwiw..

Originally Posted by 34_40

Mr. Spears... just grasping for a straw here... inspect the lifters (tops) while the intake is off. Probably all is well but,the "stuff" had to come from somewhere!

And purely as a PM task, I'd replace the dizzy drive gear pin. It's taken a nasty hit imho... needs to be changed. fwiw..

Mike,
That's a good call on the lifters. When I was talking to Scott he went over and picked up a lifter that he'd just taken out of a 302 and he suggested the same thing, look at the tops and be sure that the little spring clip is in place on all of them. Well, recall last year I had the roller pin come out of the end of my #1 exhaust rocker, and that roller bounced around and tangled with the #1 intake and that one snapped in half? Well, the spring retainer in #1 exhaust was gone, and that's the wire in the pan. Also, that "spacer" which measures 0.390"/0.290" x 0.050" thick is very likely off of the pump drive shaft, or is a "shim" in either the bottom of the distributor or the top of the oil pump. Regardless, I'm pretty sure that it's off of the broken shaft.

I also put a dial indicator on the oil pump, and the outer element ran with zero distortion (as would be expected), but the inner shaft driven element has between four and five thousandths of runout, showing that the shaft is bent which contributed to the twisted shaft.

And on a "bad things happen for good reasons" sideline, I noticed this morning that on the drivers side intake bank the intake gasket had small tears at the corners of two adjacent ports, one to the valley, and one to ambient so I've likely been losing vacuum for some time.

Headed to get parts now....