Oil pump intermediate shaft breaking

[Bubbacuda68]

Well damn. That’s a pretty thing. Maybe the new drives aren’t worth a crap.

Like I said earlier, I’ve run 125 psi on those drives and never failed one.

Unless some focknoid found its way into the pump and locked it up I’ve got nothing.

Nothing in the pump, pulled it and opened it up. Clearances still look new. Pressure is ~50 psi

 

[Bubbacuda68]

In addition to what has been said above, if it is snapping, make sure the pump is seated flush and the shaft is straight . If the shaft engagement to the pump is not straight, there will be excess stress applied to the shaft.

Also be sure there is the right clearance between the shaft and the bronze bushing as well as the mesh with the cam gear to avoid binding and excess heat build up for lack of clearance and oiling.

Also be sure the shaft length is correct. For example if the block and china wall has been machined, you may have to shim the distributed or shorten the distributor tang that engages the oil pump drive to be sure the engagement and mesh of the gears is correct.

See discussion in this recent thread starting at post #146.

http://[URL]https://www.forabodiesonly.com/mopar/threads/old-race-340-teardown.501619/page-6

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Thank you Rocket, I will double check all of those

 

[Bubbacuda68]

Try priming it with a hex shaft and drill. Put it on lock(slow speed) grab a beer and wait n watch.

Did that and damn near run out of beer.

 

[RustyRatRod]

Nothing in the pump, pulled it and opened it up. Clearances still look new. Pressure is ~50 psi

Are you 100% SURE. Does it possibly look like this? Look at the transition. It's a squared off step. Much weaker than the shaft in post #12.

 

[Dan the man]

I should have asked RRR too (he can read this and answer too) how many of these failures have you seen at the drive gear end?

I know I’ve run as high as 125 pounds of oil pressure and never failed a drive.

I also gave a theory about bronze gear wear. IMO most of the bronze gear failures are because cam thrust is not verified and corrected.

If it’s not corrected the cam can move enough that rapid gear wear occurs.

I can’t count the number of times I’ve had to machine a cam gear to tighten up cam thrust. Almost half of the builds have the thrust too loose.

Honestly I've never seen a oil pump drive fail, I've seen the gear beening wore out.