Washer agitates but won't spin

We had a burning smell in the basement and found the washer to be the source. A belt underneath that runs the spin and agitate action was burning up. So I replaced the belts thinking it was slipping from wear. No good. I replaced the springs and glides on the motor to put more tension on the belts. No good. I adjusted the pump to add even more tension and still won’t catch to spin the tub. If I push the motor all the way out by hand it spins it. The pump belt spins fine and it feels like only the spin/agitate belt is heating up and not turning when it’s on the spin cycle. I feel like at this point it’s not worth fixing but i wanted to ask to make sure I haven’t overlooked something basic before moving onto a new one. Thanks!