If your washer is not spinning fast enough, or barely spinning at all, this is usually a symptom of any one or all of the following:
1. Bad gearcase (transmission).
2. Bad basket drive, with which the transmission couples to under the agitator.
3. Bad clutch/brake assembly. Which mounts on top of the gearcase under the basket drive.
Usually a tell tale sign of a gearcase beginning to fail is the sign of an amber colored oil coated under the washer or inside the casing. I said, "usually". It doesn't always happen, but if you notice any signs of oil, the gearcase is shot. The basket drive and clutch assemblies are harder to diagnose and require some disassembly of the washer and the removal of the gearcase to inspect. Let me know if this helps.