DocT

I purchased a 928E in November from a local dealer (not Bog Box).  Came assembled.  No problems with power throwing snow, however, I have had a problem with it not moving forward when in gear.  Feels like it's slipping.  Returned once for service and they said that it must be getting moisture on the drive wheels and that causes it to slip.  It's going back tomorrow.... again;  Has anybody had any issues with this machine not moving at the speed it's supposed while in forward gear>  Thanks