Snowblower drops out of gear

Question

I have a 3 year old Toro Snow King. It is sometimes dropping out of gear.This Am when I was backing it up in #2 position reverse (the faster one,after a few feet it stopped moving). I placed it in the 1st position and it worked. I stopped and placed it in the 2nd position and it worked OK then.This also happen in the forward gear #4. It happens infrequently. I want to know if something is starting to give out. It looks like another big winter here in Wisconsin. Last year was the 2ndhighest snowfall on record. We are on the same track this year.