Broken/twisted oil pump shaft

[RODRIG3911]

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).

I replaced the timing chain myself when I did my explorer serpentine conversion. Don't remember seeing nylon on the upper sprocket of my particular timing chain when I installed it. Looking up at the timing chain from the bottom with the oil pump removed, everything looked good.. I went with a standard Melling pump, but upgraded the shaft to ARP. Just waiting for the sealant to cure before I try it out. I think I'm pretty lucky to have caught it before driving it. It was hard to start, then I heard something fall (was the oil shaft falling into the oil pan)

 

[Broncobowsher]

The nylon is only used on the factory upper sprocket. None of the aftermarket uses it. It is a nylon coating over aluminum.

You say you already changed the timing set. In that case it is left overs from the old one.

 

[RODRIG3911]

I'm completely lost now. I had finished the installation and went to test it with fresh new oil, and it still reads zero!! Old pump was locked up, new one was good. What turns it on the top end of the shaft? The distributor right? I'm guessing next step is to pull the distributor and look at the shaft correct?

 

[Mr Joe]

Check the dizzy gear and the cam gear. Pray it's not the cam.

 

[JKH67302]

Did you prime the oil pump?

Sent from my SM-G975U using Tapatalk

 

[RODRIG3911]

I took out the dizzy and turned the oil shift CCW with a drill and still had zero pressure... i took a picture where the distributor goes in and it like it may be messed up. Not sure what I'm looking at, but that circle thing that has the oil shaft inside looks wrong. For the first time ever I think I finally can't fix this myself. It sucks!!!

 

[RODRIG3911]

I think i got it!!! Got pressure finally. Stupid me forgot to prime the pump. Now to put the distributor back in and re try

 

[JKH67302]

Good deal man. Bear Down!

Sent from my SM-G975U using Tapatalk

 

[RODRIG3911]

51 pounds of pressure at idle with a standard pump and no leaks . Thank you all for the help getting through this. I was about to quit and shoot my dead horse lol. If anyone reads this in the future, don't forget to prime the pump ;D

 

[RODRIG3911]

Good deal man. Bear Down!

Sent from my SM-G975U using Tapatalk

Hell yeah, bear down man.. you were right about me not priming the pump. All golden now

 

[JB Fab]

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.

YES! Exactly what he said ^^^^

 

[JKH67302]

He'll yeah, bear down man.. you were right about me not priming the pump. All golden now

Ha! I have a wipe off board next to the Bronco right now with a list of things to not forget! Prime the pump is under fill the damn thing with oil! Glad it worked out.
James

Sent from my SM-G975U using Tapatalk

 

[stout22]

I had the exact same thing happen. Oil pump seized and the shaft twisted and snapped. It looked like a drill bit. I rebuilt the motor for good measure but don't think I needed to.

 

[RODRIG3911]

I had the exact same thing happen. Oil pump seized and the shaft twisted and snapped. It looked like a drill bit. I rebuilt the motor for good measure but don't think I needed to.

It's a crappy thing to have to fix. I got lucky and it happened before I drove off. I'm soooo glad I didn't drive away and chalk it up to a back gauge reading... I'm thinking mine was slowly getting bad over time because I went from 30-50# pressure to over 50# and my engine sounds smoother now. These dang Broncos are a blast but can be a headache when parts break. At least with your you know you've got a nice fresh rebuild