Broken/twisted oil pump shaft

[RODRIG3911]

Had zero oil pressure the other day on start up. A oil pressure oil confirmed it and I dropped my oil pan. I found my oil shaft broken in half and twisted like a drill bit. I also found a small metal piece in my oil pan that I think might have caused it. Any clue what this metal piece is guys?

What are your ideas on what could have caused it if you don't think it was that metal piece? I bought a good high volume pump to replace the old one with. Any reason I shouldn't use a high volume pump?

Thanks guys

 

[Speedrdr]

Not sure about using a high volume oil pump, but the piece of metal looks like some kind of retaining washer. That’s the best I’ve got.
Randy

 

[RODRIG3911]

Thanks Randy. You're probably right. I was thinking it was the end part of the pump shaft, but it's slightly bigger and bent in. I just hope I don't have any issues later on from where it came from

 

[Timmy390]

That piece of metal is from the shaft. It's a press on ring thing. I don't know the proper name. Mine had one on it.

As to the pump, it must have locked up......

Tim

 

[SteveL]

Theres a clip like that that goes on the shaft. Did your oil pump seize up causing the shat to break? Usually theres a sheer pin in the dizzy gear that will snap on pump failure stalling the motor. 302 or 351? On the 351w pans many of the hv pumps won't clear the front hump of the pan. It's real close but the pan won't seat properly. Not sure if the 302 has that issue. I was able to grind down the casting on the pump to clear.

 

[garberz]

That’s the oil pump shaft retaining clip. It keeps the shaft in place when removing the dizzy. If you don’t install one, you risk the chance of the shaft dropping into the pan, whenever you need to remove the dizzy.

Mark

 

[RODRIG3911]

Cool thanks guys! Now I know what that metal piece is and can start putting it back together.

It's a late 80's 5.0. I'll check clearances with my pan and HV pump before torquing back to specs. Thanks guys!

 

[RODRIG3911]

That’s the oil pump shaft retaining clip. It keeps the shaft in place when removing the dizzy. If you don’t install one, you risk the chance of the shaft dropping into the pan, whenever you need to remove the dizzy.

Mark

Mark, do this plastic retaining clips work ok? Do I just tap it in place with a hammer and a punch? Thanks man

 

[JWMcCrary]

Unless you are running higher capacity oil pan it's not recommended to run a high volume pump. It's just hardly ever recommended. I would run a stock new Melling pump. That's what I have in a stoker motor, never any issues with oil pressure.

 

[garberz]

Mark, do this plastic retaining clips work ok? Do I just tap it in place with a hammer and a punch? Thanks man

That’s not the retaining clip, a clip will come with a new shaft.

https://www.summitracing.com/parts/arp-154-7904

Mark

 

[JKH67302]

Those shafts are a weak point that break, but I've never seen what one looked like that broke. I always listened and put an ARP hardened shift in its place. It's possible that when they fail they look just like that. The rod is 30 bucks from summit.

A reinstall tip...when I did mine I neglected to adjust that retaining clip correctly and my dizzy did not want to seat all the way down. Luckily my pan was not on yet so it was an easier fix, but I would have been mighty mad if I had to pull a pan!

James

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[69_Sport]

Your oil pump likely ingested a piece of casting flash or something else that locked up the pump rotors. The engine keeps running, turning the shaft into a barber pole lookalike and snapping it.

A new pump will solve your problem if no damage was done while running with no oil pressure.

I know of more than one engine that has broken due to a high pressure/volume replacement oil pump. Resist the urge to upgrade and just go with a stock Melling pump.

Doug

 

[Timmy390]

Unless you are running higher capacity oil pan it's not recommended to run a high volume pump. It's just hardly ever recommended. I would run a stock new Melling pump. That's what I have in a stoker motor, never any issues with oil pressure.

Agree........

Tim

 

[RODRIG3911]

Got a new standard Melling now. Going for ARP shaft and bought the melling plastic retainer-dizzy oil shaft part

 

[JKH67302]

The higher volume pump puts more pressure on that shaft as well. I skipped that upgrade for the same reasons.

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[Rustytruck]

that metal is the retaining ring to keep the pump shaft from pulling out when you pull the distributer. you should pull the pump and check inside for obstruction. your pump shaft looks like it was a good heat treated aftermarket shaft. check your pickup screen for failure allowing something bigger going through.

 

[RODRIG3911]

that metal is the retaining ring to keep the pump shaft from pulling out when you pull the distributer. you should pull the pump and check inside for obstruction. your pump shaft looks like it was a good heat treated aftermarket shaft. check your pickup screen for failure allowing something bigger going through.

The pick up tube had some hard plastic stuff outside the screen (Probably something I might have dropped in from when I installed my intake manifold). I cleaned it out real good and checked for holes. I'm going to install a plastic shaft retaining ring this time. Bought the ARB shaft and really to put it all back together

 

[m_m70]

I had the same thing happen to mine in '99 with a new motor during initial break in......never figured out what had jammed the pump up but the shaft was twisted like some ornate hand railing!!

Replaced pump (standard volume) and a ARP shaft and haven't had a problem since...

 

[Mr Joe]

I've had that exact thing happen on two different engines. I'd much rather have the shaft break. Next weak link is the dizzy or cam gear. Broke those, too... That's a bioch.

 

[Broncobowsher]

Hard plastic stuff on the screen is the nylon from the upper sprocket on the timing chain. If the timing chain has never been replaced, it needs it now. If it was replaced, they were sloppy doing the job and didn't drop and clean the pan. Worth checking while you are this far into the engine.

Melling has a line of pumps (standard, high volume, high pressure) in there performance line that come with a new upgraded oil pump driveshaft. Not the fancy smooth ARP version. Looks like stock. But better materials/heat treated. Worth a look as you get a better pump than the standard pump and better shaft for less than buying them separate. The oil pump adds a lower support that you don't normally get. The pressure relief is also adjustable (at least on some).