Product review (4 stars): A Better System than Past Efforts
I'm rating four stars because I've replaced other parts several times. I'm not sure on the longevity so ...4 stars for now .

Used this kit as Whirlpool and Kitchenaid parts are interchangeable. I have left scathing comments on how bad the quality of the rack slider wheels and adjustments are on a supposed top of the line product by Kitchenaid. This kit I do have to say is much better quality and out of the box appears to be much better than the other replacement parts I've purchased for my machine KUDS30FX SS1 . I pulled my model number , searched Kitchaid's site and got the part numbers I needed and put them in search on Amazon . It crossed referenced this kit from Whirlpool. I ordered the kit for the top rack . The directions are ok , but I watched the YouTube video posted on the installation and that had great tips. Here is my tip . The kit comes with this one  black plastic screw, it's not clear as to its use , or it wasn't to me. This is the adapter you'll need to use your Phillips head screw driver to finish driving in the four screws that secure the wheels to stainless steel slide. Your Phillips screw driver will not fit the screws provided. Insert that one screw into the screw heads provided and then you can drive the screws down all the way . Silly as to why they used this method but ...
The YouTube is also good to watch for tips on how to remove the old system . I highly recommend a viewing . You can stop and back up as you need . Once I watched it was a ten minute job to install the new kit. I didn't attach a link but it's easy to find and there may be others to view as well.

The new kit has a steel slide and is very sturdy. The wheels are still plastic but overall it appears to be better. This will be about the fourth time I've rebuilt my rack or repaired issues . Kitchenaid really dropped the ball on this and they made it worse by the price they charged for the fix. At least this kit was somewhat reasonable compared to past expenses incurred to fix the corners they cut during manufacturing .