Mine did about the same thing, and it was stuck in 2nd. It's hard to tell since the 2.5 is so powerful(I assume yours is a 2.5). Mine still pulled hard in 2nd. It may seem that the truck is in 1st, but it may be in 2nd. Also check the 2spd. bell, be sure the pin is still in it, and that the one way bearing is working/in correctly.