I have a 1998 dodge 4x4 with 285/75/16. When i am driving on the highway a 70 to 80 mph the truck is shifting into 3rd gear. on my trip from las vegas to sioux falls sd i spent at least half the miles in 3rd gear. Is this normal with over sized tires or is there anything that i may need to look at? any suggestions would be great

 

dang im not sure but , sounds like u need to check ur fluids an if thats not the problem check ur brakes make sure nothings holding out like if one is clamped down like stuck or the emergancy brake cable check that , an if u do im not sure but i know on my big truck i had it was doing the same thing wich was the dam carryer bearing went out so check thoes an if nothing go to a tranny shop an see what they say ? let US know ?

 

i will check all those things tomorrow

 

You should be in 4th gear and lock up by 70 or 80.

 

a faulty throttle position sensor (tps) or brake light switch will cause it to excessively downshift. also a leaking plenum saps the power. a new tps ($45) helped mine tremendously.