rough 1st to 2nd

i have a 96 blazer with the 4.3 which has decided it doesnt want to shift from 1st to 2nd. the only way i can get it to shift is to run the rpms up to 4000 then back off and it will shift, but hard. i dont know anything about transmissions and it just started doing it and i havent had time to take it somewhere. does it just need serviced or a new filter or what? someone tell me something

I don't think changing the fluid and filter is going to fix your problem. I think it's much more severe and is going to need some trans work done on it immediately....

Get it to a transmission shop ASAP. Might be lucky and be a reasonable repair, ie, modulator or valve body, but let an expert fix this for you. They should be able to diagnose it and give an estimate.

might just be a 1-2 shift solenoid.

Check it out sooner than later.

Not having it checked out will have you replacing the tranny instead of a 20 dollar valve.