I have a 98 24 valve that seems to briefly rev up around 55-65 mph its only for a split second almost like it might be going in and out of lockup I just had a remanufactured jasper transmission installed after original went bad and this problem existed before and still exists after the new tranny my local garage tried to see if any codes came up but none were present so no one seems to know what to do at this point. talked to a Dealer and they said that it might be something in the pcm or even a brake switch of some kind but they said they might not even be able to get any codes with there scanner so where do you go from here except to start changing this part or that part
anyone ever heard of this or has had this happen to them
also can anyone recommend a good scan tool for the cummins engine

 

Ollie
Welcome to the site. The problem you describe does sound like a lock up problem. You may want to check the brake light switch in case it is a little too touchy. That will make you tranny want to unlock. Another thing to check would be the APPS (throttle position sensor). Sometimes they give erratic signals to the tranny. You can try cleaning it with some contact cleaner. Sometimes that is all that is needed. You may also want to check all the electrical connections that you can. I know it is a pain, but.......... There might be a loose connection in one. You can try going to the tranny sites and see if they can help too. Sometimes a phone call is best though.
Tom