TH350 that won't shift into 2nd

[nlped]

Okay, a quick question. I have just bought this old beater, which I was told wouldn't run, that now runs. It was a bit low on trans fluid so I added 2 quarts and it would pull like normal in 1st and Reverse. But when I took it out on its "Maiden" voyage, come to find out it won't pull in 2nd, nor will it shift into 3rd. When the trans shifts into 2nd it pulls the motor down and will actually try to lock up the rear tires. Is this something major, or is there something simple that I can check first? It does great in 1st and Reverse, and the fluid looks nice and red, but beyond that, I have no knowledge when it comes to an automatic.

Any help would be appreciated.

Ed