Washer will only spin when I help it start; agitation and fill/drain works normally

I have a Kenmore 110.20922990 washer. It operates normally for the most part (ie, fills, drains etc OK) but when it tries to go into spin cycle it has a hard time spinning up. If I manually assist it to get spinning then it’s able to maintain the rotation and complete the cycle. If I do not assist it then it tries to spin but never really get going very fast before the cycle time is over.

I found other threads (when searching for my model #) that indicated belt replacement may fix it but after reading more I’m not sure they are the right diagrams for my model.

Can someone offer some input as to what to check first and also link me to the correct diagram and parts list?

Thanks,
-Tim

Can anyone provide some input as to what I need to do in order to definitively identify the problem? I’d like to resolve this and order the part!
Thanks everone,
-Tim