Little tikes trucks wheels are uneven

SOURCE: i need four tires for my little tike adventure wagon 9x9 wheels

Contact little tikes directly. They may still sell replacement parts for your wagon depending on the model number. 

SOURCE: Little Tikes Cozy Coupe red plastic wheel caps

The caps are a type of "acorn nut". Check a local hardware store (not the big guys) for this type of fastener and bring the shaft with you to get the correct size. These should not cost more than about $.50 each.

Dan

SOURCE: Where to find bushings for front wheels of little tike wagon?

You can try these push nuts from this site:
http://www.shopjandl.com/0801-0226.html
I don't know what size of axles you have on your toy, but these fit my little tikes hummer wheels.
Hope this helps

SOURCE: I am trying to take the front wheels of a Step 2 fire truck

push them side to side as they may have we sides that lock. try diff positions when turning the wheel

SOURCE: Just ranover wheel on Little Tykes 3 in 1 Smart Trike

maybe you should look in the mirror when you back up or get a reverse camera from canadian tire