I have a 96 gmc Sonoma that I bought with about 83000 on it and now it only has around 86000. Since I bought it when driving it in OD it has never wanted to stay in overdrive when it gets hot. It will do just fine when its cold and it will do just fine when you drive it in D but as soon as it gets hot the rpms will go up and down but it is absolutely not slipping im very sure of this. I have replaced the fluid and filter but that’s about it. I have transmission experience so if there is any more information I can give you to help me out with this just let me know. Thank you very much for your help. The transmission is very very clean like it has been out and possiblely rebuilt but im not for sure about that. Also wanted to add there are no check engine lights or anything on.
96 gmc sonoma