Hey, I have a question regarding E4RS

The rear pulley that connects the belt to the rear diff, has anyone replaced it?

I bought the spare plastic ones # 503197 according to the manual. But it should be a different pulley compare to the rest used on the car. It needs a step inside to clear that extra diameter on the Alu shaft yet the manual shows that it uses the same part # as the other pulleys?

Any idea?