Is the plastic gear worn out of the wheel?

Thank you for your interest. The plastic wheel gear looks good and the issues exists without the wheel on. In other words I can grab on to the pinion gear and shop it by hand, and yet the axle continues to rotate rapidly showing that the transmission is working.

You said "In other words I can grab on to the pinion gear and shop it by hand, and yet the axle continues to rotate rapidly showing that the transmission is working."

How could you stop the pinion gear (number 4 in the picture) and yet have the axle rotate, The pinion gear drives the bevel/ring gear (# 6) which turns the axles. The pinion gear is connected to a pulley which has a belt connected to the engine pulley. I don't see how you can stop the pinion gear from turning with the engine running.

The pinion gear on my model (Toro 20065) sits on the axle, away from the transmission and fits into the plastic gears on the inside of the wheel. When inserting the pinion gear on each side of the axle, there is a "half-moon shaped key and spring that needs to be depressed so that the pinion gear will slide over it. I think the spring and key (not sure) may allow the wheels to move backwards when the self propel handle is not engaged. So just like the wheel spins slightly forward when the front wheels are off the ground, but stop rotating when on the ground (and hence no self propel), I can grab on to the wheel or the pinion gear (when the wheel is removed) manually and stop them from their weak rotation, yet the axle continues to rotate from the transmission.

Your #6 bevel/ring gear is internal to the transmission and my pinion ear is on the axle.

Thanks for your interest. It is pretty frustrating. I need to find a little more info as to what the key (#15 part # 612066) and spring (#14 part # 39-9650) actually do on my model.

A couple thoughts. 1) Check the key in the drive pulley on the engine shaft 2) That you have the correct transmission. Front wheel drive and rear wheel drive model transmissions look the same but actually power in opposite directions. 3) The springs can be stretched a tad. The gears themselves are directional as well.

HU could you post the model number and serial number for your mower. The parts diagram that I posted was for a toro 20065.

Always_beezee, the model number is 20065, S/N # 27090465, 2007 model.

B&S engine 124T02 0161 B1. Thanks for your interest.

Hi tomplum. I am not sure what you mean by the key in the drive pulley. I had replaced a broken flywheel key a few months ago when it would not start and it fixed that problem. But I assume you are referring to a different key and not the one's in the front axle that the pinion gear goes over.

It is a front drive mower and i think I used the correct transmission, 106-3955. I know the pinion gears are directional (by inserting one side wrong). I assume they are in the correct direction because when the wheels spin slowly, it is in a forward direction on both sides.

Thanks again for your interest.

HU, If i was you, i would back up and kinda start from the beginning.

Take the cover off the belt. Run and engage the propel. Is the belt tight? Can u turn the pulley on the self propel by hand while the belt is supposed to be tight?

A stretched belt has happened....

The belt looseness is something I have always wondered about. Even with the self propel engaged, I get at least 3/4” of play, meaning it is not tense. It does cause the axle to turn but perhaps not enough. I can turn the pulley when self propel is engaged but the belt does not rotate wIth it, I guess b/c loose. It is a new belt and it’s the correct toro part number stamped on it. As far as I know there is no way to adjust the pulley to tense the belt. Also I have noticed that the transmission is moveable, meaning I can rock it. It is not fixed.

Your thoughts and thanks for your continued interest.

The problem turned out to be that the pinion gears were not oriented correctly. With the reference point being the operator's position (behind the mower or behind the handle bar), the the markings on the pinion gears should be "L" mark facing out on the left side and the "R" marking facing out on the right side. I had them oriented the opposite, using the front of the lawnmower as the left and right reference points. As soon as I switched them to the correct orientation, the mower self-propelled!

The belt is still loose and I can squeeze both sides together even with the self-propel engaged. I thought of getting a shorter belt, but now this is no longer necessary because it propels. I guess the belt is not meant to be tight like on a car.

I thank everyone for their interest. Nice to have this over with.!