Self-Propelled WON'T Self-Propel?

[philadelphia1]

So I got a new belt today and slapped it on and nothing......still doesn't move. When I tilt the front wheels off the ground they spin.... same as with the old belt, the second they make contact with the ground they stop? Double checked everything and nothing is apparent. Back to the drawing board. What shall I check next?

 

[BlazNT]

Remember when I said something did not look right? I would like for you to check the arm in question for travel. May need 2 people to test this. The self propel bar needs to be engaged then the arm needs to be checked if it will go any further towards the pulley. Do this with engine off. Repete do this with engine off.

 

[primerbulb120]

Remember when I said something did not look right? I would like for you to check the arm in question for travel. May need 2 people to test this. The self propel bar needs to be engaged then the arm needs to be checked if it will go any further towards the pulley. Do this with engine off. Repete do this with engine off.

And once you get done with that test, have another person start the mower. Then go around to the front and make sure that the belt is not slipping on the transmission pulley.

 

[philadelphia1]

I checked the arm for travel while off and engaged, it is completely bottomed out...no travel whatsoever. I made a youtube video to give you a better perspective rather than a still pictures and words.

-https://youtu.be/KITqp1KET9c


I also made a video of the test you wanted me to do Primerbulb....it doesn't appear to me that the belt is slipping across the trans pulley? Not sure though?Also, have a look at the wheels when I lift the mower they slightly spin. The wheels are brand new.

-https://youtu.be/x2uRbkyd0YE

 

[primerbulb120]

Thanks for the videos, they're a big help when trying to narrow down the problem.

The problem is clearly not with the transmission or belt, as I can see the axle spinning even when the wheels are not.


Remove the front wheels. You will see two small metal gears, one on each side of the mower, that are supposed to mesh with the wheels. With the mower off, engage the self propel and try to spin one of the gears. The gears should be impossible to spin with the self propel engaged. If you can spin them with the self propel engaged, I think I know what the problem is.

Report back with the results.

 

[philadelphia1]

Hello again Primerbulb120,

With the self-propel engaged and the mower off I can get the pinion gear to move quarter turns but is very difficult to do so. I also notice that the level on the tranny twitches when it moves a quarter turn. Have a look at the video.

-https://youtu.be/7_pfXk5VuKY

Also took some video of the pinion gear itself.

-https://youtu.be/txt3ThiMoCk

My brother is a mechanic and he stopped by last night and we were trying to troubleshoot everything and he suspects that the dowel pins within the pinion gear are shot and need to be replaced? What are your thoughts?

Thanks!

 

[primerbulb120]

Hello again Primerbulb120,

My brother is a mechanic and he stopped by last night and we were trying to troubleshoot everything and he suspects that the dowel pins within the pinion gear are shot and need to be replaced? What are your thoughts?

Thanks!

I agree. I originally thought that somebody had removed the dowel pins altogether, but they're obviously still there. Since the axles are turning but the wheels are not, that either means that

1. The pinion gears are not turning
2. The front wheels are the wrong size and the pinion gears are not turning them.

If the front wheels are the right size, the pinion gears are not turning. This could be due to one of two things:

1. The pinion gears have been switched around. THEY ARE NOT INTERCHANGEABLE. They should be marked "R" and "L" for right side and left side. Make sure the old ones have been installed correctly before you replace them.
2. The pinion gears and/or dowel pins are worn out. I would suggest replacing the gears along with the pins, as they both wear equally.

Apply a liberal amount of grease to the dowel pins, the pinion gears and the ends of the transmission shaft (where the gears and pins attach.) Then re-install them, paying attention to the "R" and "L" markings. If the mower still won't propel itself, post back and I will give you links to the pinion gears and dowel pins.

 

[philadelphia1]

Hello again,

So I double checked to make sure the pinion gears were properly oriented....while facing the mower from the front the gear labeled "R" is indeed on the right side and "L" is opposite. I greased the transmission shaft at either end, reapplied the dowel pins, pinion gears and put the wheels back on and still get the same results. They only spin when lifted off the ground. I made a video with the mower while started and the drive engaged to give you some perspective of the pinion gears moving with both wheels off.


https://youtu.be/jcnqOBsL3Vc


I'll also post some close-ups pictures of the pinion gears and pins. Some of the pinion pics are before and after I cleaned them up.




How do they look to you? Relatively worn? Anything that immediately catches your eye?

 

[primerbulb120]

Now switch the pinion gears and see what happens.

 

[philadelphia1]

Nope, nada, no dice brother....switched sides with the pinions and nothing. When I tilt the mower upward the wheels don't spin, just tremble.