how can you tell if your trannsmission is slipping?

im getting 14 mpg and would like to rule out the tranny is going out.

oh and i checked for codes and didnt get anyting.

 

Generally speaking you can get the truck running fast enough to be in 2nd or 3rd gear. Hammer the throttle and see if the engine revs more than the truck takes off.

 

When I had the auto tranny in i was in that mpg bracket with a bully dog torque dog. You also can definetly tell when your trying to go and the engines accelerates but your truck doesnt. If it is slipping, youll also notice that icky fluid smell!

 

Take a large chain..attach one end to your truck..and the other to a large tree..the tree will let you know..check your fluid to see if it is discolored or smells burnt and follow what the other dudes said..i just had mine go out about two months ago and my fluid was dark and stanky, i was getting bad mileage like you and it took ten minutes to get up to interstate speed

 

well it has plenty of power, not as much as i think it should, and my fluid looks brand new, tranny temp never goes over 180F

 

A failing vp could cause low mpg..are you asking because you used to achieve better mileage?

 

no ive had the truck since last august 2010, and everyone near me that ive talked to is getting 18-22 MPG. i would just like to get better summer i get 15, winter im getting 14