First off let me start off by saying I don't know much about working on a transmission but I was wondering for some advice as to what could be wrong. I have a pretty much stock GN with 122000 miles and I don't race just cruise. A few weeks ago my transmission would not shift into second until around 3500rpm and 3rd around 5000rpm. Both seem too high for street driving and they never have shifted that high before. So I checked the fluid and it was a little low so I added some. Now it shifts erratically if at all. It will only shift out of 1st until around 5000rpm. I can't drive faster than 30mph or I am afraid it will redline the motor. I checked the fluid level which is fine except there are bubbles in it. I don't understand how my transmission suddenly could get this bad. Is there anything that I can check to fix this problem myself without going to a tranny shop or could my transmission just be completely shot? Any advice would be appreciated. Thanks in advance for the help.