Not too familiar with your particualr vehicle, but I will try to offer a few suggestions. Some vehicles come with overdrive switches in the cab that allow you to shut the overdrive off. These can short out. Your tranny might also have a selenoid that's going bad or perhaps you just need to flush the tranny out.
auto or man? auto change trans filter and add new trans fluid I'd use lucis trans fluid. cable could be streached
I was told it was like the check engine light which means a trans problem. it could also be that your overdrive sensor is bad and not have transmission problems at all. although it can be costly to fix if you cant do it or know someone who can.
check trans fluids and the vacuum lines going to the trans, could be the kick down linkage as well.
more likely a supension or tire problem, depends on where you're feeling it vibrate.
MY 98 HAD A BROKEN CLIP ON FORWARD CLUTCH VALVE SPOOL IN VALVE BODY
my check engine light stays on and the o/d light blinks....what could this mean?
Air vibrates helmet. Helmet vibrates helmet (two). Helmet vibrates air (inside helmet two).
The transmission for the 1996 Chevy 3500 could be jumping from overdrive for several reasons. The transmission could have a vacuum or electrical problem causing it to come out of overdrive. Or, there could be an internal valve problem causing this to happen.
overdrive could be ready to go out might be the cluthes
No. Three speeds are normally without overdrive. There may be another transmission that you could replace it with to get overdrive.
It is probably a failing fan.
I certainly wish I had the answer to your question. I have a '97 Expedition that does the same thing. First and second are fine, but 3rd gear and overdrive under moderate acceleration seems to be early. I have serviced the trans, checked the TPS, etc and have seen no difference. It shifts and downshifts fine, other than that. I guess I just won't worry about it until it finally starts acting crazy. Hope you are able to find the answer.....I have had no luck.