You may want to read this thread over on
RV.net
It seems the OP had a "caliper stick" and after repair the ABS would come on now and then. After that he started have tranny problems. The OP called Workhorse and was told fix it on the recall... just drive it.
WRONG ANSWER! OP then contacted Allison and they said the ABS does have an effect on the tranny. New ABS sensor and the problem goes away.