Try someplace like Graingers. I am not sure about the wheels on the Rubbermaid but my guess is they are plastic. I have not seen plastic wheels for sale, only steel.

Would these wheels work? They are on Ebay. See the link below.

Here is a link that might be useful: Wheels on Ebay

I think you can find what you need at McMaster-Carr's website. On their homepage, look under Material Handling and click on wheels. That will take you to page 1286 and you can go from there.

This link was posted here several weeks ago and I want to thank the OP for it.

Here is a link that might be useful: McMaster Carr homepage

Try this site. According to Rubbermaid they make the carts.

http://www.rubbermaid.com/rubbermaid/support/contact.jhtml?cat=Garden%20Carts

Here is my solution:

http://www.amazon.com/gp/product/B0021BWK5Y/ref=oss_product

Free shipping. The bore on this wheel is 3/4" and the shaft is 5/8" so you will need a flanged sleeve (2 per wheel) available from smallparts.com:

http://www.smallparts.com/Oilite-Sintered-Flanged-Bearing-FF711-01B/dp/B000FMW5KQ?ie=UTF8&qid=1268514794&sr=1-5&pf_rd_r=0NZQW3BD8TRA7WK2CF1B&pf_rd_m=A2LPUKX2E7NPQV&pf_rd_t=301&pf_rd_i=0amp;pf_rd_p=493388211&pf_rd_s=center-3

The tire is solid which is a plus but you should know that if you replace only one wheel, the original wheel is slightly larger so the cart will list to one side. I don't find it a problem.

You need the medieval package. Put the wheel together as best as you can I used a piece of 1/2" plywood scrap that I sheet rock screwed into the side wall. I used a hole saw to cut out around the hub. I drilled and used #10-32 nuts and bolts to attach to them. The 1st one took some time, but the 2nd was easier.

"You need the medieval package." AWESOME! My sister has one of these w a broken wheel . The "OEM" Rubbermaid ones were hecka expensive. I had mentioned that Lowes had some that may work for ~ $20- but don't know what happened. Andy, you should post a pic of the medieval version and I'll forward that along...

Sorry, no pics. The repair piece was a piece of 1/2" plywood as big as possible to span the outside diameter of the wheel. Clamp it into place and trace out the cuts with a pencil.