Oil Pump Shaft keeps breaking

Andrew C

Six Sense of Frenzy
I have a 1996 Mustang which was in Muscle Mustang and Fast Ford we were the first to break the 500RWHP mark years ago.

We have been breaking and having continuous issues with Oil Pump Shaft Gear and bolt. Breaks bolt and spun gear.

Has anyone come to fix this solution. I DO NOT want to Dry Sump it.
Hardened Assembly? Hardened shaft and Gear with larger bolt? Anything?
Here is what car has
Engine -
8.5:1 Compression ratio
Decked and bored .030 over
Moran Racing Stage 3 crankshaft
Eagle H-beam connecting rods
Diamond custom forged aluminum pistons
Morana Racing Main stud girdle
Morana Racing ported and polished cylinder heads with larger valves
Morana Racing custom roller camshaft 0.538-inch lift
1.73:1-ratio Comp Cams rocker arms
Multi-layer Steel head Gaskets
Morana Racing intake manifold
ProCharger D1SC - 13 psi
Nitrous Express 75 hp wet shot
Reichard Racing pulleys
ProCharger three-core intercooler
ProCharger aftercooler ( Kryonics nitrous spray)
Performance Autowerks/SCT tuning
Walbro 225-lph fuel pump
Aeromotive fuel-pressure regulator
Larger fuel lines
Custom Morana Racing fuel rails
62-pound injectors.
Drivetrain –
T-56 6 speed manual transmission

Fully hydraulic Tilton clutch pedal and release bearing

Centerforce Dual Friction clutch

Pro 5.0 shifter

Custom aluminum driveshaft
Interior –
Custom Autometer carbon fiber gauge cluster with integrated shift light
Dual AEM air/fuel ration gauges
Custom Nitrous activation panel
2 tone grey/black leather seats
Momo steering wheel, shift knob and emergency brake handle
Suspension/Chassis/Brakes –
Baer 13” big brake kit F&R
Eibach lowering springs
Koni shocks
Kenne Brown Strut tower brace
Kenne Brown chassis braces
Exterior –
Saleen urethane body kit
Saleen fiberglass hood
SSR GT-3 18” wheels
BFG Tires


Boosted V6
Cool build! What weight oil and oil pressure? Do you have any pictures of where it's breaking? A lot of times the cam gear breaks causing oil pump failure. This is due to the cheap cloyes oe replacement not up to par with its metallurgy.

6 Shooter

Well-Known Member
Never had that problem in the past with the D1 ProCharger setup. First some questons--What brand of oil are you using? What weight of oil? What oil pressures are you seeing at idle and WOT. If you are just using the Ford oil pressure gauge, consider getting an electronic oil pressure gauge for inside the car. Very helpful.

For snapping shafts, you may be getting too much oil pressure which the shaft always sees/feels. So, if you have oil pressure in the 90s at idle, that is too high. 75 at a cold idle is good and should drop down to 25 at warm idle. At WOT and 190 coolant temps, max oil pressure of 75 would be great. For a stronger shaft, find a shaft made from 4340 steel material. Maybe Morrso makes one. And, you may have metal in the pump gears which is adding extra resistance. Maybe a chipped gear or a gear with a burr on it. It is also that oil is not making its way into that shaft area to keep it lubricated to reduce friction.

Another possibility is valve spring binding. Coil binding would lock up the cam gear momentarily and the oil pump shaft could not keep up and twist off. What is the clearance on the springs with the cam at full lift?? 50-60 thousands would be the minimum. 90 thousands would be the max in my opinion.

When you pull the twisted shaft, is it dry?? Would also pull the Cam position sensor and shaft out of the motor and examine it and the brass bearings for scraping, warping, unusual wearing, etc.
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