Hello All. I have a Scotts (John Deere) 21 inch self propelled mower, and it only driven by one wheel and pulls to the left. I have removed the cover and the gearbox (3 speed) is turning both axles, though the right wheel is the only one driven. At the end of both axles at the wheels, there are small gears that drive gears attached to the wheels. The gears appear to be meshing ok. It seems that the left wheel is geared to operate in the opposite direction to the right wheel, but the gearbox rotates the axles in the same direction. Is it possible that something is wrong in the gearbox ? Thanks in advance

 

Both axles should turn the same direction as they are. Pull the drive gear off the axle and inspect the condition of the inside of the gear. There is probably a pin going through the axle behind the gear as well. If this is stuck, it won't drive the wheel.

 

Thank you for the response. I have removed the gear, and have found a spring loaded woodruff key. The gear has 3 internal slots with ramps that only allow the key to engage the gear in one direction only (clockwise). I have cleaned and regreased, and have done the other side as well. It too also will only lock in the clockwise direction. Tried swapping the small gears to the opposite sides, and the internals are machined identical so they are interchangeable. I always thought that the axles would turn in the same direction, but I don't have the experience to know positively.

 

If both shafts turn the same direction, and both gears are machined the same inside with the ramps going the same direction, then one side will grab, the other will slip off the ramps. The gears should not be the same.

 

The only thing I can think of is ease of turning, sort of a differential. I had the gearbox apart (real character builder), and from what I can see the axles are to turn the same way. I do know that if the right wheel starts to slip, it does not kick over to the left wheel for extra traction.

 

You May Want To Clean Of The Greese And Just A Dab Of Oil... Greese Will Hold The Pins Back From Engaging... As This Happens On The Old Craftsmans...

 

I'll give it try ! Thanks..

 

These two pinion gears should be directional whereas if you have it installed 180 degrees from what it should be then it won't drive. Don't change sides with one another, simply take the side that is not driving and flip it end for end. I suggest thoroughly cleaning out the keyway and using emery cloth on the keys then using a "00" grease sparingly in the pinion gear area.

 

The gears are open on one end only. On the other end of the gear the hole is too small to slide onto the shaft.

 

Post back, if you would please, with the chassis model and serial numbers. What is the visible model number (usually indicated by way of sticker on the fuel tank/shroud cover)?

 

Has one of these gears been changed? Has the self prop worked on this mower since you got it? I still maintain that it sounds like you have two like gears, instead of one with the "ramps" in one direction, and one the other. The gears should not be the same inside.

 

Product I.D. #6XSP63X035874
Model- THD walk 38P
Date Code- 032300
Briggs and Stratton 6.5 HP Intek
John Deere, Moline Illinois

There is also a bar code if needed.

The 2 gears are identical and original. The mower is 5 years old. I am still trying to clean and relube. The self prop has always worked, but I am trying to recall if this problem may have started when I did a pm. Maybe the grease is too heavy as suggested. I am able to send a digital pic if this would assist.

 

I have cleaned off the grease, and applied a couple of drops of motor oil. As the lawn is wet, I haven't tried it yet. Pushing it around in the garage I am hearing a clicking noise that was not occuring before the oiling. Reading the manual it appears this is a good thing, as it says "Rear wheels will make a clicking noise when mower is pushed forward. This indicates that the drive train is operating correctly". I'll update when the grass dries. Thanks

 

Cut the grass and it is not pulling to the left anymore. However the right wheel is still the only wheel driving.