I agree with Mark McCulley - some binding on tight turns in the syncro
seems normal to me too.
My Trooper II binds more in a full-lock turn than the syncro - even
when in 2WD!  In 4WD it needs a loose or slippery surface since it
doesn't have those nice viscous couplings.  On a dry surface in 4WD it
will crab, hop, squeal and generally act ridiculous.  Yes, I know, the
Trooper is about as sophisticated as a 7lb. sledge - but it makes the
syncro system look REALLY good.