I replaced the rear drive wheels on my 20334 Toro Recycler because the tread was bald. The old wheels had steel gears (115-4695). The new replacement part has a composite material for the gear and was worn out in 3 uses. It is very soft compared to the steel gears. The new Part number is 138-3216. I have been doing some research and people are not getting much life out of these newer wheels with the soft gear. Someone metioned a kit you you can get that has the steel gear. He was not very clear or descriptive. Can anyone comment on this. Is this a real up grade or just some hack someone did in their shop.? I would like to get a pair of wheels with steel gears. I have been looking and they seem non existent. I did look at the alignment and it could be a bit better but it is not bad. I had no issues with steels gears. Help appreciated. Thanks.