# Oil Pump Drive Rod has a twist?



## torpedo51 (Sep 8, 2009)

I pulled the engine out today to get to the oil pump, because engine has no oil pressure until 1500 rpm. Its a 65 389, with hydraulic lifters.

There was some sludge on the oil pump screen. The oil pump itself appears to be fine. I did notice that my oil pump drive rod has a twist. (See photo).

Is this normal?


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## Jerry64 (Apr 20, 2010)

Don't look twisted to me.Clean it up then look at as you can't go by a sludge line.....JB.


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## torpedo51 (Sep 8, 2009)

The question isn't whether my part is twisted or not, its definitely twisted. The question is - is a twist normal?

That sludge line that you see is filling a groove/score, and there are several smaller grooves around it that aren't filled with sludge that follow the same twist line.


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## Eric Animal (Oct 28, 2007)

torpedo51 said:


> I pulled the engine out today to get to the oil pump, because engine has no oil pressure until 1500 rpm. Its a 65 389, with hydraulic lifters.
> 
> There was some sludge on the oil pump screen. The oil pump itself appears to be fine. I did notice that my oil pump drive rod has a twist. (See photo).
> 
> Is this normal?


I don't think so...."when in doubt, throw it out"....check the oil pump for wear/binding. Check the distributor for a worn gear and to make sure it turns freely. Check your cam gear, and front cam plate.....


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## geeteeohguy (Feb 2, 2008)

I agree with Eric!!


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## Jerry64 (Apr 20, 2010)

Did you look at the slots in the ends?Put a file in the slot at each end and look down the shaft..It will look like a + or an x or both will line up straight across top to bottom......I have seen what you are showing on them before and they were not twisted as it was the way they rolled the steel.........JB.


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## OrbitOrange (Jul 5, 2010)

The only time Ive ever seen that part twisted is if the oil pump locked up. Ive seen them actually break in 2. ARP makes a hardened oil pump shaft.


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## torpedo51 (Sep 8, 2009)

When I check the angle, it's not 90deg. It's more like 75 deg. 

I'll replace it - they're only about $10. 

But, my oil pump and distributor seem fine. I wonder if this part was reused from a prior rebuild... and I wonder why it needed a rebuild. 

Thanks for the replies


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## tyscru (Sep 29, 2009)

I would be very concerned that you had no oil pressure until you reached 1500 rpm. Personally I would replace the oil pump if I had the slightest doubt. The pump could be worn and on the verge of failure and might have bound to twist the drive rod. In any case the oil pump is the heart of the engine and if you have it out why take a chance with the rest of the engine if it fails or doesn't supply adequate oil. With inadequate oil pressure you lose the film preventing the crankshaft journal from rubbing directly on the rod or main bearings and can destroy the bearings in short order especially if you are driving at high speed or rpm.


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## Rukee (Feb 8, 2007)

:agree replace the drive rod, oil pump and the pick up screen too.


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## Eric Animal (Oct 28, 2007)

$100 worth of cheap insurance:agree


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## BearGFR (Aug 25, 2008)

I'm running one of these:
Standard sleeved & hardened oil pump driveshaft
I really like the sleeve on the pump end that positively locates the shaft on the pump. The one caveat of this that they tell you about in the installation instructions but not on the web site, is that you have to check to make sure you've got adequate clearance between the crank counterweight and the pump shaft. Mine was fine, but you do have to check it. To get a little more clearance, if you need it, you make sure the pump is pushed as far away from the crank as you can before you tighten the pump bolts, and you can elongate the bolt holes in the pump body just a touch if you need to.

and one of these:
Pro-oil Pump Plate
The plate is about double the thickness of the stock plate so it won't flex, and the laser cut oiling grooves for the pump gear faces make the pump last longer.

On a Melling M54DS pump, with this Mildon pickup and pan:
Milodon 18425 Milodon Oil Pump Pickup Tubes
Milodon 30355 Milodon Street/Strip Oil Pans

I agree that if you found the pump pickup filled with sludge and you've got other weirdness happening with pressure, don't fool around with it and take chances. The consequences of not getting it right can be very damaging to both your engine and your bank account.

Bear


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