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Common issue with the yd25 engine is that the oil pump gears wear on the drive flats. The oil pump gears are sintered (powder metal heated and compacted in a mold) This is a widely used process that helps manufacturers keep costs down. However, it can result in inconsistent metal density which leads to rapid gear wear. See examples below.

New Oil Pump Drive Flat	Worn Oil Pump Drive Flat

 

Sintered materials are prone to shattering. If the gears are hit when reinstalling the harmonic balancer pulley it can break the gears. Aggressive rev limiters and crank walk-in high-performance engines also put a lot of stress on the oil pump leading to shattered oil pump gears. 

Sintered Cast Gears Shattered Into Multiple Pieces

 

D22 OIL PUMP DESIGN ISSUES

With a standard D22 engine the sump must be removed to remove the oil pump. The first photo shows the oil pump backing plate protruding into the sump. This is why the D22 sump must be removed first.

The second photo shows the oil pump with our upgraded oil pump backing plate installed. With our backing plate we have machined the section that drops into the sump, a fitting is then inserted into the sump to make up for the material removed from the backing plate. A oring is used to seal between the oil pump and sump like a d40 setup. With our back cover kit fitted the oil pump can be removed without removing the sump. 

D22 ORIGINAL OIL PUMP		OIL PUMP FITTED WITH UPGRADED BACKING PLATE	YD25 D22 UPGRADED BACKING PLATE KIT

The first photo shows our D22 oil pump rear cover kit. The second photo shows our complete D22 upgraded oil pump with our billet gears, modified , and oil sprayer fitted.

YD25 D22 UPGRADED OIL BACKING PLATE KIT		YD25 D22 BILLET IMPROVED OIL PUMP