MDZ2

Thanks for the excellent analysis and bearing link. 

Thanks for your replies.  The model is 932101  -  824.  I'll try to explain more - hopefully with the right terminology.  This involves the axle that the wheels ae mounted to.  The axle passes through a bearing that is part of or within a hexagon shaped outer "nut".  This "nut" sits in the orange housing, in a hexagon shaped hole.  There is no other bearing retainer or fixture.  It's just this hexagon shaped nut in a hexagon shaped hole inthe housing.  Same on both sides.  The hexagon shaped hole has worn, I guess, to be a hole larger than the hexagon shaped "nut" allowing the motion I mentioned above.  The axle itself is nice and tight within this bearing/nut, but it's the nut that moves with respect to the hole in the orange housing.  If I hold the nut down and back in the hole, the gears mesh.  The gap is about 1/8 inch on the top surface of the "nut" and the adjoining next surface of the nut, toward the front of the machine.  Maybe JB Weld to fill that gap? 

I have a 7 year old Ariens 824 with drive problems.  I replaced friction disk and that didn't fix issue.  The axle bearings themselves are ok - but they are loose in the opening in the housing.  The gap that exists allows the two gears inside to not contact each other.  If I take the weight off the wheels by supporting from underneath, I can push the axles down, thus making the gears mesh fine.  But the weight of the machine on the wheels during use pushes the axle up in that gap, allowing the gears not to mesh.  Is there a shim or something I can use to take up the space between the outer surface of the axle bearings and the orange housing through which they are mounted ?