Differential lock broken pins?

[Rosohatica]

Hi all,

Some of you may have read my earlier post about working in very muddy conditions. If not, it’s here for context:
https://www.orangetractortalks.com/...o-to-or-on-your-kubota-today.6326/post-823323

Today I tried to engage the differential lock, and the pedal goes down very easily with almost no resistance. That immediately raised a concern, so I reviewed the correct operating procedure for the diff lock. Unfortunately, I realized that on that muddy day I engaged it completely against recommendations—while the wheels were already spinning, likely with one wheel spinning freely in the mud while the other was not.

Based on what I’ve since read, engaging the differential lock under those conditions can cause the differential lock pins (or dogs) to break, which would explain the lack of resistance at the pedal. I’ve also found that this type of failure seems relatively common on the BX series, with several videos documenting it, for example:

From what I can tell, the BX differential uses four pins. My questions are:

• How many differential lock pins does the L series use (specifically the L3200)?
• How common is this type of failure on the L series ?
• What is the easiest or least invasive way to confirm whether the pins are broken?
• If this is indeed the case, should I stop operating the tractor entirely until it is repaired?

Thanks in advance for any insight.

 

[JasonW]

It could be the return spring for the lever.

Does the diff lock still work?

I don’t think the pins are as fragile as some say they are, I’ve seen some rough operators engage the lever with one wheel spinning and the other stopped, but no damage occurred.

The wheels spinnings isn’t an issue it’s if there is a difference in speed between the two wheels is where it can cause damage.

 

[NCL4701]

How many pins? Based on the parts diagram at Messick’s looks like 8? Kind of hard to tell the way it’s oriented in the diagram, but more than 4.

How frequent do they fail on L’s? No clue. I know the first time I used mine, I was acting before thinking instead of thinking before acting, so didn’t do it anywhere near right. Almost immediately thought “probably just shredded the diff lock”. It’s still fine.

Easiest/least invasive way to check? Try it and see if it works. Find another mud hole. Jack up one side just enough to get one wheel barely off the ground. Find some wet grass you don’t mind tearing up, lock the diff, and make a sharp turn. Probably many other options to test its function.

Should you continue to operate if the pins are sheared? Others likely have more expertise on that question. I wouldn’t be very comfortable with substantial chunks of metal rattling around in a box full of gears.

 

[TheOldHokie]

View attachment 167246
How many pins? Based on the parts diagram at Messick’s looks like 8? Kind of hard to tell the way it’s oriented in the diagram, but more than 4.

How frequent do they fail on L’s? No clue. I know the first time I used mine, I was acting before thinking instead of thinking before acting, so didn’t do it anywhere near right. Almost immediately thought “probably just shredded the diff lock”. It’s still fine.

Easiest/least invasive way to check? Try it and see if it works. Find another mud hole. Jack up one side just enough to get one wheel barely off the ground. Find some wet grass you don’t mind tearing up, lock the diff, and make a sharp turn. Probably many other options to test its function.

Should you continue to operate if the pins are sheared? Others likely have more expertise on that question. I wouldn’t be very comfortable with substantial chunks of metal rattling around in a box full of gears.

Its easy to check the lock. DIsengage MFWD, put the loader up against a big tree, engage the lock, and spin the rears. It wont tell you if ALL the pins are intact but personally I am not going to tear it apart because I thin pleasek I MIGHT have damaged one. I did have the lock on my B7200 wear out and stop working. It used a solid dog clutch rather than "shear pins".

Dan

 

[North Idaho Wolfman]

The Diff lock on a L3200 is much better than the lock on a BX.

There is 8 pins that engage the diff lock.
It's not very likely that you sheared all 8 pins.
Also these L's don't make it very easy to engage when the wheels are spinning.