Hello there, I need help. I have a Toyota AT 170 Corona. (automatic transmission) Recently while driving I noticed the RPM started to go up. And as that was happening, the speed decreased. Later on that same trip as I stopped on the road. I wasn't getting any gear. No reverse nor forward. I shut off the engine and restarted immediately. And the transmission worked again for a bit. My mechanic checked it and said I need to change transmission. We got a foreign used one but my problem is still existing. With this one now, as I drive, the gear doesn't change as it suppose to. I notice the RPM goes to 4000 before the gear change. Please advise.