I’ve owned this 97’ 250 hd xlt for about 4 months now, it has 272,6xx on it right now and I bought it at 262,xxx miles. I drive a lot of highway miles on it. Not much up and down shifting, and about 2 weeks ago my transmission started to shift hard going from 1st into 2nd. (((I noticed this would happen after It got up to temp. I took the same route every morning to work and it would almost do it at the exact stop sign I hit everyday. )))It would make you let off the throttle because you anticipated it to shift hard and no body likes the feeling of that. Over the next couple days after putting some Lucas in the tranny it started to change from a hard shift at normal rpm range from 1st to 2nd to a very high rpm shift that was much Smoother just very high rpms about 2800 to 3000 if I didn’t let off the throttle, If I did let off the throttle I’d get it to shift at a lower rpm but still on the higher side probably around 2000 but it would take a good 15-20 seconds to shift through and the shift would be very slow. If I try to explain it I would say it did half of a shift then wait 3-5 seconds and then the other half and by that time I’d be going fast enough for the tranny to jump over 3rd gear and straight into 4th. So I came on here and read some some what relatable posts about a week ago. I saw the VSS is the first thing most people say to replace as it’s the cheapest so I did, I noticed my speedometer stopped bouncing around, (it use to bounce around a lot once I hit about 60mph). But after a couple days it didn’t fix my transmission problem, though it seemed like it didn’t do it as often as I said it was erratic and sometimes the tranny would shift fine after I stopped at a light. Then the next light it would go back to high Rpm smoother shift. So I now thought to myself well the tranny fluid smells used, still has a pink pigment to it but is obviously on the older side and I haven’t changed the tranny fluid or filter since I bought the truck. So that’s what I did. I found a very good amount of very very small dusty sized metal shavings on the magnet, probably a good 1/4inch surrounding the whole magnet and then a couple l/2 to 3/4inch long but very very thin metal shavings. The tranny fluid was definitely on the darker side but still had the pink pigment. The filter I thought could be clogged up and causing this problem so I changed it as well. Next day I drove it and it shifted like it normally did all the way to work which is 75miles and 75miles back. Next day I drove it a little faster and got the EOT up to 208 and TFT to 181-184 and that’s exactly when it started to kind of shift in the high rpms but this time it was 3rd gear, the next light I came to I anticipated the same thing but it didn’t happen and it’s been a 2 days now where it’s been shifting like it should, normally shifting. Yesterday I actually noticed the shifting points seem a lot more smoother and faster meaning one shift happens quicker and smoother than I remember it ever doing. And the truck seems likes it is running better as I’ve been getting on it trying to see if the shifting problem arises again. But it hasn’t. Could anybody have any input on what happened or are there any other tranny sensors that help the computer know what rpms to shift at. I know the gauge cluster gets information from the VSS and translates that to mph and then sends that information to the computer for shifting, but is there any more electrical things other than those that help. And also could it have been my accumulator body, like a stuck valve or spring or whatever are in those damn things and now it’s freed up. Whatever input someone has please feel free to add it in, I know it’s fixed at the moment but it’s only been a couple days with it fixed after I changed the tranny and filter. Thanks!

Is the O/D light blinking?

with big metal shavings I’d say it’s time for a rebuild

no it is not I forgot to mention that. That’s the first thing I looked for. O/D works perfectly fine.