Hi, thank you for choosing Justanswer, I look forward to helping you resolve your issue. Have you checked the fluid level and condition? Remember you need to check the fluid when it is hot and the trany is in neutral. If it is black or smells burnt you have a internal trany problem. If the RPM's are going up but engine speed is not increasing then the clutches in the trany are slipping and the trany would need to be overhauled.