Caster angle ??, any techs out there?

[IslandSport94]

Just had 31's put on and had truck realigned. It now is very "twitchy" in the steering dept. Any little bump will sent it all over the road. If the alignment was set to factory specs, will the effect of the taller tires throw off the caster angle? Would adjusting the caster forward a half degree or so help tame this sucker?
I assumed going in to this that I would have some steering wander from the fatter tread blocks moving around, but this is a real handful to keep under control.
BTW, 31-10.5-15 Bigfoot XT (mud) fits with only minor rubbing on the tupperware at full turn.

 

[WLax007]

Well usually factory settings is specifically for the stock tires and only work for stock tires (depending on the type of suspension and manufacturer). If its "twitchy" this could be numerous things, but yes caster effects the ability to make tires go in a straight line a great deal. It's similar to how a front bicycle tire works or a shopping cart wheel. So try it...and if its still "twitchy" bring it back to the shop. 90% of the time this is the problem so good luck

 

[IslandSport94]

Thanks for the reply, I'll give it a try. Oh, and Happy Birthday!