[Richard]

Hmmm, there is no way that DANA had a seal made just for that application. You may be able to pull a number from the old seal and use that.

OK, I am about to get knee deep in the woods here on a quirk of that specific front end. The literature says the castor is not adjustable. That is true. But some some shops will cock the A arms with unequal shims to achieve the desired castor. Josam did this to my coach. BUT>>>>>that only works if the upper and lower A arm joints are ball joints. My Prevost has ball joints so this technique works. HOWEVER, the DANA IFS 84 front end has robust tapered roller bearings in the pivot area. If you cock the A arms, you put the bearings in a misalignment bind. Why do you care, because that bind makes the steering wheel hard to self center when at freeway speed. I know this is an esoteric point, but you should know.

The castor is adjustable but the mount where the A arm attaches to the frame must be tilted up or down relative to the frame on both the upper and lower A arms. This can be done by slotting the mount and using shims to between the frame and the horizontal section of the mount. It’s not trivial.