Well I figured that it would be better to put both problems in one thread instead of two. First problem I noticed today that my front tires are wearing more on the inside instead of evenly. I haven't noticed anything different other than pulling a tad bit to the right but its very minimal. Would it be possible that my dif fluid needs changed(might be causing a bind when turning???)

Second problem at 55mph im at about 1,500 rpms(thats normal) when I let off the rpms go down a little bit. Now If I give it a little bit too much throttle when its cold(after sitting all night) and if I were to let off at 55mph my rpms would go down to about 500-800rpms and you can watch the needle surge from 500-1000rpms until I get back on it but it will only do that if I do it when its cold and it will do that until the truck cools then it will be fine. It wont do it if I take it easy until it is warmed up. I have no clue what is causing it I know I could just take it easy until its warm but thats not always easy(people dont know how to drive where I live plus I have patience of a 3 year old)

 

Sounds like you have a alignment issue if your tires are wearing on the inside, rub your hand over the wear front to back, and back to front. If both are ways are smooth its a camber problem, if one way is smooth and one way rough then your toe is out.


Your other problem can be many things, could be a sticking Thorttle body butterflys, bad Throttle positioning sensor, or a sticky IAC Sensor, they are all loacted on the Throttle Body itself. The IAC can be cleaned off, but dont be to rough with it, it can break, the thottle body can also be cleaned with some carb cleaner, take it off the truck when cleaning it and disconnect all the sensors from it.

The surge could also be your truck telling you it needs a tune up.

 

it sounds like you definitely have an alignment issue, check your ball joints and tie rod ends before you have it done.

And like User said i would check your IAC for your second problem.