98 1500 5.2 litre 4WD. I was driving down the freeway at about 60 went to pass and the truck started to surge like it was not sure to go into overdrive or not. The belt was slipping so I replaced that and the squeaking is gone but the truck still acts like it is looking for a gear when it shifts. Could it be an o2 sensor or the tranny?

 

My truck does this with regular unleaded. And not with premium.

 

If you were going 60, you were already in overdrive. I think what you mean to say is that it didnt want to unlock the torque converter and/or downshift (depending on how far your foot was in it).Possibly the torque converter clutch giving up the ghost, or if you were laying into it, (which would make it try to go to 3rd) a band in need of readjustment.

I'd bet money it's not the o2, in any case.

 

I am about a 500 miles away from my next tune up and a band adjustmant is in that one might just have it done early and see what happens.

 

even when I am just gradually comming up to speed it will do it now, if I am trying to hold a certain speeds it's like it isn't sure what gear to be in.

 

Did this develop immediately after what you first posted, or was there a period after that it seemed alright at low speeds?

Edited to add: Is it just when you try to hold speed at around shift points, or does it feel "choosey" no matter what speed you're going? Did you hammer the throttle to pass that old lady, or just put your foot down a little bit?

 

it started after I changed the belt and tensioner. It seems to be more consistant at shifting speeds. I was gradually accelerating and tried to punch through the "slipping".

 

my truck does the same thing. if i punch it and let it downshift, then its great. no problem. but in last gear, it'll surge or whatever you want to call it. i have not tried a different grade of gas though. i wish i wouldve thought about that. i just got gas today

 

Belt and tensioner would have nothing to do with it, this appears to be a tranny problem. Just for fun, check your TV cable, it may be out of adjustment.

If that doesnt fix it, next in line would be to drop the pan, and see what the fluid looks like.

@veritas: If you are having tranny issues, a different grade of gas would do little more than lighten your wallet.

 

True, trans issues will be unchanged by different fuel.

Maybe my truck is sick, but on my 97 Ram1500 with reg. unleaded on a highway, 55-65 MPH, any head wind or little high will get it to kick out of OD. And with premium, it takes a big hill.