Anyone had a problem removing the back plate that holds the sierra drum brakes from the drive shaft. The last one I did years ago just slides out as per the Haynes manual. This set (both sides) seems to be too big, i.e. the drive shaft (just before the rubber boot seems bigger than the hole in the back plate.

Anyone any ideas.... I have removed all the rust from the drive shaft and inside the backplate hole and it still a few mm too big. I want to remove them so I can properly clean and repaint.

Really frustrating!
Thanks
TimN