Added Caster to my 4106.....

[OneLapper]

I took the kids to VT for Labor Day weekend.  Bus ran great, no issues at all.  From day one, though, my bus wanders down the straights, requiring constant correction.  Left right left right left right, you all know the drill.  Even though I've done some 1000 mile days in this bus, it's always been tiresome having to constantly correct the steering wheel.  Frankly, I have been disappointed in the steering despite installing power steering, new tie rod ends, rebuilding king pins, bushings, airbags, etc. etc.  

Today I was under the bus greasing all the fittings up front and decided to adjust the caster.  The coupler on the upper radius rod was removed, cleaned, neverseized, and reinstalled a few years ago when I swapped in a rebuilt front axle, so the effort to get it to move was minimal.  When I installed the new axle I used the same measurements as the old axle, making an assumption the alignment was correct.  I turned the coupler two full rotations to increase caster, tightened it down, and took it for a test ride.  The bus tracks straight as an arrow now!  No more wandering, no more constant corrections needed, it now steers just like driving my TDI down the road.  I can't wait for our next trip!

[chessie4905]

   Ive mentioned that adjustment several times over several past posts, but few probably have done it. It will increase low speed steering effort some, more noticeable with manual steering. Most of the GM's need this adjusted if they wander.(after removing slop or play from worn components. )

[luvrbus]

Today's tire technology has changed so much over the years it's almost impossible to make a old bus drive perfect with the limited caster you can have,nothing to see the modern buses and trucks running 7+ degrees of caster.not to far back no one ever heard of a steer tire     

[OneLapper]

   Ive mentioned that adjustment several times over several past posts, but few probably have done it. It will increase low speed steering effort some, more noticeable with manual steering. Most of the GM's need this adjusted if they wander.(after removing slop or play from worn components. )

I would think that with manual steering you would notice the additional caster at slow speeds.  With the Sheppard system I'll never notice it, I can steer in a parking lot with one finger.  It took me about 30 minutes to make the adjustment, nothing at all.  I don't know why I didn't try changing it years ago.  I admit that I don't have a clue what the actual caster is right now, but since it steers so much better going down the road, I don't think it really matters.  I'm due for some new steer tires in the next year or two so I'll keep a eye out for additional cupping, etc. on the fronts.  The next trip is to Wachusett Mountain's Applefest, a short drive but mostly highway so I'll have ample time to enjoy the improvement!

[Darkspeed]

OneLapper, glad you got such good results with this! I just did mine at the suggestion of Clifford @5 deg but it will be a while before I am able to try it out. The only wear point that might get accelerated is the rubber bushings in the front suspension track bar (control arm) because as you add caster you are creating a twist that is absorbed by those bushings but it is not very much.