Transmisson fluid lube guard additive

I changed my trans fluid and filter almost a year ago and its all Dexron 3, I think it needs some lube guard to keep the trans running good. What kind of additive did you guys use?

probably doesn't need any additive, but lubegard is a good product for sure. It can help with alot of little quirks in the shifting etc... Use lubegard red, the green is for fords and the black has additional friction modifiers that are not good for these electronically controlled transmissions. There is also a shudder fixx additive i found worked in my friends car, but again i dont think its required.