Front wheels lock up when pull mower backwards

your drive will driver dogs are full of dirt you need to remove both wheels and clean the dirt out the dogs are spring loaded be ready for parts to spring out maybe depends on how much dirt

Leave aside all the puffery about 3-1 and such, you described a front wheel drive (pull) walk-behind (FWD), but are asking why the rear wheels won't propel. When you push down the hand grip the front wheels should spin free. Whan you lower from wheels by releasing pressure on hand grips, turning wheels lowered to ground should propel the mower along with its unpowered rear wheels now turning be ground contact. Reminder, never, ever lift rear drive wheels of any mower off the ground while walking behind with engine running:

1. You could be struck by blade propelled object.
2. You could pull mower and spinning blade backward onto your feet.
3. You could lose balance and be pulled forward in a fall.

Contemporary FWD mowers are recognized by a black chain housing on deck top leading from engine to left front of deck. RWD propelling chains are situated underneath deck so cannot be seen from above.

most have small leaf springs that let it toggle back and forward, if they brake can cause this problem. Then it may just need the wheels removed, clean the parts and lubed

pull off what looks like hub caps and check the wheel clutches

put belt dressing on the belt

turn it off,let the drive handle go,pull mower backwards.does it lock the back wheels?if you push it forward,can you hear a clicking noise from the wheels?you should do.lift mower,spin back wheel,should either lock,or click,depending which way you spin it.they have spring loaded pawls that drive the wheel.usually easy to fix.usually dirt,or too much grease.take wheels off,have a look

remove the front black plastic plate that is stamped self propelled and replace the wheel drive belt that attaches the engine pulley (above blade) to the transmission pulley (found under the cover). When you buy the belts, pick up two or three as I seem to go through a couple per season. Hopes this helps

Take the front tires off, pull gears and take out pins, put tires back on and you have a "non-self propell" mower.

ya the trans is trying to go out and thay look up thay do that all the time