Another gadget that needs identification

[viento1]

The bus has a heavy duty spring on each side of the steering knuckle.  As the wheels are turned from side to side the springs will tension up to return the wheels to the center. I have a broken one and the local bus mechanic has never heard of such a contraption. My other 68 MCI had the same thing but someone cut all the springs off. What is it? and should I fix it?

[Stormcloud]

Something like this?

http://www.steersafe.com/

[viento1]

Great, thank you. Mine is not as sophisticated but essentially the same thing. I wonder if those springs will work with mine. Either way, I am off to find a replacement spring and enjoy all the magical benefits of such a thing.

[buswarrior]

You'd maybe best to go find a pair?

I'm ambivalent towards them in the first place, but having an old weak spring on one side and a new strong spring on the other can't be a good thing?

happy coaching!
buswarrior

[kingfa39]

had a simular set up on my 4106 because it wandered, was a mistake , i did not like the way it drove, rebuilt the whole front end ,put a shepard steering on it, still wandered, had it lined up, still wandered, finally did a little more checking and found the tow in towed out, reset it and i could take my hands off the steering wheel at 75 mph and it would go straight as a arrow. Alighment people messed with it all day calimed they changed all kinds of things the truth is they didnt do anything but make belieive. i thought i was good to go. wrong.
  but you should not need a spring set up to return wheels to center. front ends are designied to go straight
Frank allen

[Utahclaimjumper]

 Another thing to check is axel castor,, just re-adjusted one that had 6 degrees negative instead of 2 degrees positive, made whole world of difference.>>>Dan (4106)

[bevans6]

From the previous conversation on this topic, the steer-safe type springs were initially popular on manual steering trucks to assist in steering in the event of a blow-out tire failure on the steer axle.  They really weren't supposed to stop wander.  If you think about it, the springs are in balance when steering straight, they have very little effect on anything.  When a "wander" occurs, the steering angle is so low that the springs still have very little effect, and other mechanical forces are more in play.

As noted, castor is very important, it is what generates the self-centering effect.  On old buses with manual or pre-integral power steering, the castor was set very low - 1.5 to 2 degrees is the spec on my bus - and that gives almost no self-centering effect but does encourage the bus to steer straight - no wander.  Toe in is also very important - a tiny bit of toe in is put on most buses to pretty much simply eliminate the urge to wander while not incurring a lot of tire drag and wear.  I haven't checked but I would think that most buses have some decent Ackerman built in, so that the bus rolls easily around corners.  What that means is that as soon as the bus is turning the front wheels start to go into toe-out to encourage the turn. 

We recently learned (new to me, that's for sure) that modern equipment is being set up with a lot more castor that the old stuff had - Clifford said 6 to 10 degrees!  That will give a massive self-centering impetus, that can only be overcome with modern power steering.  At the same time, I bet the toe-in setting is tiny - keep those wheels rolling straight and low drag.  For me and my bus, with the miles I run, I would keep the toe-in where it is, just set to the high side of spec, I would add a degree to two degrees of castor, and I have the upgrade to Sheppard steering already in place to help me deal with the tougher steering that the castor will bring with it.  In practice, though, after getting a four wheel lazer alignment that confirmed the correct factory settings, loosening up one kingpin that had been installed too tight and wasn't getting lubricant, and correcting the one real problem - the drag link was an inch too long so the Sheppard steering box was dramatically off center - my bus is now very happy to drive.  Adding castor would be a major project, so I won't bother.

Brian

[Oonrahnjay]

    Very good post, Brian; thank you.