Is my 904 toasted?

Hey guys,

I have a 904 with a factory stall converter behind a mildly built 318. I bought the trans used a few years ago, slapped it in the car and it has been working well since. The trans has a shift kit but is probably stock beyond that.

A couple of weeks ago the shift into 2nd gear started getting sloppy - like it didn't have a shift kit. No longer was it shifting into 2nd with firmness. Now the shift into 2nd is even more sloppy, and if I lay down any sort of power in 2nd gear it slips. The shift into 3rd is fine, as is all other operation of the trans.

Do you guys think it needs a rebuild? If so, is there a recommended rebuild kit I should get?