Backhoe NEW MT225S owner....mechanical thumb issue

wraven · May 16, 2021

OK... Went easy until I curled the bucket to align for the pin. I started hitting the thumb with the bucket gusset and when I went to back off I moved the control the wrong way and started shearing the bottom of the thumb (See #1).

Please take a look at this composite image. Is your thumb and bucket fabricated the same as mine? I am trying to decide if I want to modify the the thumb or the bucket. I don't think either will affect the strength but what do I know. Opinions?

I am leaning toward grinding on the thumb. (the Left side is almost done already anyway).

kormidoit · May 16, 2021

wraven said:
I paid $285 for the mech thumb here in Pennsylvania. I just did my 50 hour service (at 65...shhhh) and I am getting ready to install the thumb that sat in my shop all winter. I'm glad I checked here before starting. Thanks for the discovery, kormidoit.

LS Tractor Owner · May 18, 2021

wraven said:
OK... Went easy until I curled the bucket to align for the pin. I started hitting the thumb with the bucket gusset and when I went to back off I moved the control the wrong way and started shearing the bottom of the thumb (See #1).

Please take a look at this composite image. Is your thumb and bucket fabricated the same as mine? I am trying to decide if I want to modify the the thumb or the bucket. I don't think either will affect the strength but what do I know. Opinions?

I am leaning toward grinding on the thumb. (the Left side is almost done already anyway).

I would grind the thumb... lots more pressure / stress on the bucket. My neighbor has the 225-S, the dealer ground the thumb when they ran into the same issue.

It was one of the first thumbs that came from LS, I believe they changed the manufacture of newer thumbs due to the same issue...

wraven · May 18, 2021

LS Tractor Owner said:
I would grind the thumb... lots more pressure / stress on the bucket. My neighbor has the 225-S, the dealer ground the thumb when they ran into the same issue.

It was one of the first thumbs that came from LS, I believe they changed the manufacture of newer thumbs due to the same issue...

I wound up grinding on the thumb and a little bit off the bucket gusset. I can always weld something back in if the bucket appears to weaken. I also ground off the tabs on the adjustable brace so I can use the close pivot and store the thumb up against the dipper when it’s not in use.