apowell

We changed the fluid and filter, also MAP sensor was bad. Still had shifting issue. Finally found bad ground cable terminal at the battery. Cleaned it up and replaced the battery terminal and now it seems fine.

Sitting Bull

Thanks for the feedback, apowell. Much appreciated. Hopefully it keeps running well for you!

gwgeep

I replaced my Radiator fluid which is where my tranny fluid circulates thru and that solved my problem. For a couple of years I checked and cleaned everything else....so I thought about the times when it hard shifts and that is when it is hot outside or going long distances and the tranny gets hot. So, I figured I would replace the fluid with new 50/50 mix. Whenever I replaced the radiator fluid I never had the hard shift problems now that I think about over the years. It shifted hard right after I bought it used 16 years ago. Then I routinely flushed the radiator...but then when I was not routine and let it sit for along time...I had issues. So, temp of the tranny fluid running thru the radiator was my problem. It runs like a dream now.

Sitting Bull

^^^ Good info, that makes sense. Thanks, dude.

apowell

The transmission started acting up again. Doing the same thing but now the truck sputters and dies. Already replaced MAP sensor, TPS, VSS, fluid and filter. Getting a little tired of throwing money at this problem.

z-man1

I hear ya, man! I can be good for almost a week, then it acts up for one or two stops, then clears up again. I think mine is due to a bad computer ground on the driver's side fender in the engine bay. You might also need a reman computer - there's a thread out there somewhere (maybe here? this is a quick reply) on how to replace the computer caps. I say it's a bad computer ground because the other week I had some really weird errors come up (bad memory, 2nd fuel rail bad when there's only 1) and that's what leads me to think it's just a simple ground. Heave black wire coming out of the harness going right to the fender.

GL...

z-man1

Yup, jinxed myself after typing that and going for a 3 mile drive. Stopped at a red light, went to take off and it wouldn't shift smooth. Looked down & noticed I didn't have a speedometer OR odometer for a few seconds! All of a sudden the speedometer came back up, odometer showed all "8"'s, and shifted fine for the rest of the drive. I'm still leaning towards a bad ground somewhere...

gwgeep

Is is possible to relate the problem to trans fluid heating issue? What I mean is since the fluid runs thru the radiator can you try to run the heater for a period of time to see if you can get some heat from the radiator fluid while driving and that in turn gets rid of the heat of trans fluid that is passing thru the radiator? My trans hard shifted the first day of hot weather here after 6 months of no hard shift when we had cool weather. I tried the last couple of days driving with the heater on and there were no hard shifts.

One thing I did notice the other day was I let the engine run in the drive way to cool the car off, then I started driving and it hard shifted very quickly, when usually I get the hard shift later in a drive. So, I keep tabs on the times when I am idling in traffic or sitting around waiting for someone with the engine running. During the cooler months mine runs like a dream.

I even checked my EGR valve and cleaned it the other day thinking that the engine was heating up because the EGR valve was staying closed under load and the engine temp might be getting hot quicker. Gotta give it a go..
I am sure my hard shift is trans fluid temp related; just have to figure out a way to remove the heat quicker. Heck, could be the radiator fan is not spinning fast enough to remove the heat. It looks like I have one of those clutch fans...???