manco 7150 rear wheels loose
 

I have a Manco 7150 I got for my boys about a year ago. Ever since we got it the rear wheels have been loose. We tried tightening the wheel bolt but they're still loose. They fit over a splined axle shaft. Are they supposed to be loose? doesn't seem like they'd last long that way. Now I've also found one of the wheel hubs is broke. still wobbles on the splined shaft.

It is not uncommon to have some slop there. The wheel bolts to a hub and the hub has splines that match up to the splines on the axle. They simply do wear over time but again that is not that uncommon. Sometimes you can tighten the big nut that holds the hub on. Don't over tighten it to the point where the wheel has a hard time spinning though.