Recently our walk behind just stopped moving! The engine runs fine- The belts are all connnected(looking worn but are working)- it just won't move forward or backwards- blades engage- if I pick up the back end the wheels move, but when it touches the ground i get nothing.

 

I am assuming it is belt driven to the gear box assembly, and a
large belt driving each wheel on the side, and not hydro stat.
You either have a belt slipping or a gearbox problem.
Remove the belt from the engine to the gearbox, and with
the mower on the ground{not running of course} engage the
wheels, so that if it was running it would go forward.
Then lay on the ground and rotate the pulley at the gear box.
Keep rotating by hand and see if it is slipping inside the gear
box. If not, then the belt must be the culprit, either too loose
or oily, or if it has the variable speed pulley, it may be frozen
and you need to pull back on the ground speed lever to tighten
the belt. Let us know.
Fish

 

Hello and Welcome NoSoup4You to my Small Engine forum.

Fisher makes several excellent possible problem suggestions.

I would like to add one other possible problem location to check.
Remove the wheel caps...hub caps...on the drive wheels and you may find broken metal spring clips.

The drive clips attach to a gear assembly. The gear assembly has splines and will be attached to a drive shaft. Attached to this drive shaft gear will be about 2 or more two metal spring clips.

The clips will be centered in the gear and the outer ends of the metal spring clips will be pushed into a ridge in the wheel. The friction of the clips holding to the wheel turns the wheels when the drive shaft rotates.

The clips {2 or more per wheel} may be broken.

Regards and Good Luck,
Small Engine Forum Moderator
Tom_Bart Company Enterprises.....TCB4U2B2B
"Accurate Power Equipment Company"
Small Engine Diagnostic Service and Repair Technician.
Personal Quote:
"If it ain't already broke, don't fix, tinker or fool with it until it is broken!"
Disclaimer:
Bare in mind my company no longer services nor repairs small engine powered equipment. The information provided is accurate to the best of my knowledge...except during "Senior Moments."