03 cummins knock

[Red Sleeper]

When I had the cab off my 05, I still had to raise the engine for clearance between the front axle and oil pan in order to change the gasket. Not much, maybe 3"-4" and you could get by.

Is your truck 2wd or 4wd?

 

[ComnRailPwr]

You can raise the truck up on jack stands or with a lift and let the front axle drop all the way down. That will give you enough clearance to drop the pan. If just changing the gasket you can probably wiggle it around the pickup tube without taking the pickup tube off. If not then you have to pull the pick up to to get the pan off.