transmission shifts through first, second & into third then stays in third. i am wondering if this could be related to towing. i have owned this vehicle for 170,000 out of it's 230,000 miles & only just recently towed a 2500 lb trailer of firewood. now suddenly i have a blown head gasket & transmission that won't go past third.
transmission won't go past third gear on 1991 GMC Suburban 2500
by dwallyt in Waynesboro, VA on December 22, 2010
ANSWER by Visitor on February 19, 2011
get a new one and make sure its the high performence