2014 International ProStar with a Heavy Lean, help!

Steer axle spring bushings. Have to jack up front end by lifting frame and letting axle hang free. Watch the rear shackles on the spring as you slowly jack it up and see if gravity pulls them down farther then they should go or if the bushing moves fore and aft. They should not.

 

Pull a tape and measure wheel base on both sides. Check the right front carefully as, if something wonky is going on on the right spring in length for whatever reason, ( bushings as was mentioned, wrong spring or whatever), this can cause the wheel base to be shorter on the right. That could cause it to pull right even though the ride height was higher on the right.

 

Pull a tight string from eye to eye of each front spring and measure from the string to the same point on the spring perch. Also measure the length between the eyes.
Consider changing or at least re-arching them if there is more than 3/8 inch difference.

Navistar (IHC) has had supplier problems with the lighter (12k and lighter) springs. I changed my 12k springs on my 96 3 times before I installed air bag assist with twin leveling valves.

 

Just spitballin' ideas but what if you found a nice, level pad somewhere to park on and then measure from the ground to the bottom of the frame rail at all 4 corners. That should at least tell you if the cab is leaning due to suspension sag/frame issue. If the frame is level L to R then you know to focus on the cab/cab mounting.

 

Forget the hood. Measure distance between ground and bottom of frame, just above the axle. Compare to opposite “good” side. If the “bad” sides lower, ( it should be, if it’s a spring problem) then measure between top of axle and bottom of frame, on both sides. If spring, or hangers the problem, the distance should be less by at least the same amount as the first measurement, compared to the “good side” Maybe a little more, due to weight shift, and possibly a weakened spring from the leaning. Another way is to jack up, the “bad side” frame,
till the Trucks level. Then measure from bottom of frame to ground, on both sides, and from top of axle to bottom of frame, on both sides. If frames bent, the distances on the “bad side” will be more than the good side. Check the shims on the axle. Someone may have left one out on the bad side. Shims are often different on each side, up to 1/2” from the factory to level the Truck, from frames that aren’t perfect. Hopefully the frames not bent, and it’s a weak spring, bad hanger bushings, or a combination. A shim can be added if needed depending on how bad it is off, and what shims are already being used. I went through this on a 92 WS. Eventually took a week on a frame machine twisting it a little everyday. Back to Original and then some. Till it found its original temper. It was good as new. Whatever the problem it can be fixed.