17 Pathfinder oil pump.

[C-10guy]

I am working on a 2017 Pathfinder 3.5 VQ35DD. Upon disassembly, I realized the Gear that turns the bottom mounted oil pump is only held in place on the crankshaft by the torque of the main pulley bolt, against the timing gear, then against the oil pump gear. No keyway, no pins etc. Can this possibly be right? 2 slick surfaces pressed together with a bolt to turn a gear? Meaning if the bolt was the least bit loose, the oil pump would not turn. I can find no info on this, the parts diagrams do not even show that gear or chain that drives the oil pump. I am perplexed. Thank you for any info.

[smj999smj]

The end of the crank that drives the oil pump has two flat-sided surfaces and the gear of the pump has two flat-sided surfaces inside of it. So, when the pump is installed, the flats of the oil pump gear must be lined up in the direction of the flats on the crankshaft so that it will slide all the way on.

[C-10guy]

No Sir. The 2017 VQ engine is a different design. The oil pump is mounted on the bottom of the engine block, driven by a short chain from that gear on the crankshaft. I assembled it, torqued the bolt to spec and everything was fine. But I still find it odd that the sprocket is not keyed to the crank like the timing sprocket. The sprocket has a key slot, but no keyway on the crankshaft.