After getting the new ready for action, I turned attention to the old.
As discovered when I replaced the drive cogs on the Rover, the wheel backing plates were damaged and letting too much debris to enter the drive systems rotating assembly. After scouring the internet proved fruitless, I sent emails to a couple of mower shops pleading my case. All but one couldn't help, but I now have two replacement wheel backing plates.
So, it was off with the wheel and drive cogs, a now familiar process.
The backing plate is secured by a single pop rivet, which I drilled out.
The new parts didn't have the hole for the rivet, so I put the new cover on the machine, offered up the old one and used it as the guide. After trying to secure the new cover with bolts I had in stock, I gave up and had to go out and get some replacement rivets.
With the new backing plates fitted, I applied grease to the axle and drive shaft, re-installed the drive cogs and pawls, followed by the wheels and a slug of graphite powder to lubricate the cogs.
A quick test run to verify the repair, and its driving both wheels and seems to be producing less noise as the old plates were scraping against something.