Yanmar YM1510D – Front Wheel Assist Not Working

[bmaverick]

Update:

Thanks again, everyone, for all your help so far. It’s been reassuring to know that I can ask questions here and get such thoughtful advice.

I was working on my tractor again today and wanted to share what I’ve found:

• I removed the left axle cover to check for stripped gears—so far, nothing looks destroyed in there.
• I pulled the driveshaft, and the lower U-joint looks a bit scuffed up. It’s not completely broken, but I think I’ll go ahead and replace it.
• One thing I’m still debating: On the front differential, where the driveshaft connects—if I spin that input gear, I would expect the axle spindles to turn. However, they’re not.
• Looking behind the left plate, I can see a gear spinning, so something is moving internally.

My main question now: Is there some sort of clutch or mechanism in the front differential that engages the wheels? If so, I’d like to understand how it’s supposed to work so I can troubleshoot more effectively.

So far, I’m encouraged not to have found any completely destroyed gears—just the chippedView attachment 3884820View attachment 3884821View attachment 3884822 gear I posted about earlier and the U-joint that needs replacing. If anyone can help me identify how this front differential functions, I’d really appreciate it.

Thanks again for all the guidance.

— Matthew

Like this,

 

[YanmarMatt]

I originally thought I could buy the U joint replacements from brand M parts, but it looks like it’s just some of the components. The part that looks worn on mine is the part that attaches to the input drive for the front differential. I don’t know if replacing those roll pins would help. On that input drive it looked like it was a slotted for a key however the U joint didn’t seem to match that key. I don’t know if the key portion would’ve got worn off, either way the input drive is not spinning the axle drives as I would have expected.

 

[bmaverick]

 

[winston1]

Long video but might be worth your time.

 

[bmaverick]

Long video but might be worth your time.

Winston, amazing video, thanks for posting. This goes into all kinds of details for the 4WD system. I learned a bunch from this, even though I have 2WD.

Yanmar made the system rather easy, not difficult.