Whirlpool 3RGSC9400RL0 not spinning correctly

Hi,

Was called out to this reported leaking. Machine is used in a dogs kennel so full of dog hairs and suchlike. Turned out the machine was overfilling and water was getting over the top of the drum. Pressure chamber seems clear but sealed onto tub so replaced pressure switch and machine now fills to correct level and doesn’t leak.

However, the machine now doesn’t spin at the correct speed – probably about a third of what is normal on these machines. I did notice the gearbox was pretty rusty from the leaking (they had continued to use it while leaking for some time) – could this be the cause of it? I see very few of these machines, normally coupler replacement or inline fuse so a bit stumped but eager to learn :).