Kenmore 80 - Doesn't spin when draining

I have a Kenmore 80 series washer that functions well overall. The problem is when the washer switches from "Agitation" mode, to drain/spin.

I hear the pump kick on and water starts going down, as well a motor noise, but the drum does not spin. I cannot move the drum by hand at all. (Locked hard). I did smell a little burning when it was left like this for a long time.

If I release the lid switch, everything starts shutting down, then CLUNK and something engages the drum and it moves just a little. Then I press the lid switch and it starts spinning and draining as normal.

Please forgive my ignorance, I read through the sticky posts, but wasn’t quite sure.

Is it a brake not releasing? I can take video if needed. Thanks for any help!

Go ahead and check the clutch and the brakes, but my fear is that something is wrong with the transmission. Your machine probably has neutral drains, that means the tub does not spin for a couple of minutes while it drains. After that time the timer pauses the motor, which causes the transmission to shift in tub drain mode.

I think what you are hearing when you lift the lid is a heavy shift by the transmission.

It may be that the timer is the problem, that it is not pausing and that the thud is just normal. I would start by replacing the timer and see if that fixes things.