upper_tanker
I'm Awesome
My dad has a 1997 K2500 5.7/80E, uses it mainly as a plow truck but takes really good care of it, it's his pride and joy. It has had an issue for this and last winter where you'll just be driving it and it will shift out of overdrive into 3rd. It seems like there is nothing obvious causing this. It doesn't happen when you hit bumps, and when it does happen, it's not going up a hill. Your foot's just on the gas cruising and it will shift down. He's been complaining to me about this for a while. I finally got to drive the truck a few times and see what he was talking about.
The first time I experienced it was a few weeks ago. I was taking a load of tires (off the rim, not heavy) about 6 miles away. I warmed the truck up in our shop, made it all the way there, and then it did it when I was halfway back. Just driving, foot steady on the gas, and it shifted down. I tried to feather the gas a bit to see if it would shift back up into OD but it didn't. I also tried moving the gear shift lever to 3 and then back up to OD, nothing. I just went on another trip to drop another load of tires off today and it did it pretty close to the same area. Made it all the way there, and halfway back it did it. When it does shift into OD, all shifts are nice and smooth/firm. When the OD issue happens, the 1-2 and 2-3 shifts are neck breakers.
The trans was rebuilt probably 3-4 years ago by the same shop who rebuilds all of our transmissions. They (at least used to do) nice jobs and we've never had any issues. We took it to them before last winter to check it out and I think they put a solenoid in but I can't remember. I want to ask if anybody knows of anything that I can check here before we take it back to them. It's out of warranty now obviously so whatever the issue is, he will have to pay for it. Just curious to see if anybody else is having this issue or knows what I can check.
I have checked the cab mounts and trans/engine mounts, they're all good. Engine and trans mounts were new when the reman engine was put in 8k ago, and the trans mounts were new when they rebuilt it 6kish ago. I don't see any oil in the trans plug, and it seems like the shift cable is nice and smooth with no binding. I do know I put a new cable in it probably 2-3 years ago.
Anyone have any ideas?
The first time I experienced it was a few weeks ago. I was taking a load of tires (off the rim, not heavy) about 6 miles away. I warmed the truck up in our shop, made it all the way there, and then it did it when I was halfway back. Just driving, foot steady on the gas, and it shifted down. I tried to feather the gas a bit to see if it would shift back up into OD but it didn't. I also tried moving the gear shift lever to 3 and then back up to OD, nothing. I just went on another trip to drop another load of tires off today and it did it pretty close to the same area. Made it all the way there, and halfway back it did it. When it does shift into OD, all shifts are nice and smooth/firm. When the OD issue happens, the 1-2 and 2-3 shifts are neck breakers.
The trans was rebuilt probably 3-4 years ago by the same shop who rebuilds all of our transmissions. They (at least used to do) nice jobs and we've never had any issues. We took it to them before last winter to check it out and I think they put a solenoid in but I can't remember. I want to ask if anybody knows of anything that I can check here before we take it back to them. It's out of warranty now obviously so whatever the issue is, he will have to pay for it. Just curious to see if anybody else is having this issue or knows what I can check.
I have checked the cab mounts and trans/engine mounts, they're all good. Engine and trans mounts were new when the reman engine was put in 8k ago, and the trans mounts were new when they rebuilt it 6kish ago. I don't see any oil in the trans plug, and it seems like the shift cable is nice and smooth with no binding. I do know I put a new cable in it probably 2-3 years ago.
Anyone have any ideas?