W900 cab lean

I imagine the air supply on leveling valve is 1 line split into 2. You could swap bags, That would tell if it’s the bags. If valve has individual lines could swap them too. One bag being fatter makes sense if it’s been running lower. I assume you checked part #’s on bags. What about the cab/frame torque/stabilizer bar? Bushings good?

 

How about the chassis air bags? Are they all inflated the same? Need to use a tape measure. Bottom of frame to top of axle. Kenworth has problems with rear bushings. Could be transferring weight to cab. I had a WS that eventually figured out the frame was twisted. Finally got it figured out. Had it straightened. A slight twist or can make a big difference, once the weight is shifted. The old stretched out bag is suspect. Is it the problem, or a result of a bigger problem?

 

Definitely look at your cab mounts in the front, measure the distance from the air bag mounts to the top of the frame, and also inspect the mounts on the sleeper, occasionally they can break and collapse.

Those bags look pretty old as well, wouldn't be a bad idea to replace em before they blow.