3-Point Hitch L3710 Removing lower arms

[L3710]

I am trying to replace the lower arms on my L3710 and it looks like the pin holding the arms in terminates in the brake case. The pins are very rusted and won't budge. Please help?

 

[L3710]

Here are a couple of pics of what I am fighting to remove. The balls inside of my 3 point arms are rusted and are very loose in the arms

 

[rbargeron]

With the bolt out, try welding a lever to the end of the pin. After it cools use some PB Blaster and some heat on the iron around the pin. If it won't lossen, may need to take off the brake housing and drive it out from the inside?

 

[L3710]

That's what I was afraid of about removing the brake housing but not sure what would be available inside there? I also was told to try to heat up the pin and then let it cool and use an air hammer?

Thanks again

 

[rbargeron]

If its a blind hole you could drill a 3/8 thru to the end of the pin and knock it out?

 

[L3710]

Yep. Kubota dealer confirmed its a blind hole and does not extend into brake case. Said they would probably have to cut it off with a torch and then burn the remainder of pin out of blind hole in brake case. I tried some heat not red hot and nothing. Tried Freeze Off penetrator and nothing. Been soaking with pb blaster for 3 days and not budging. It appears the ball is froze onto the pin, cause the arm moves freely, is wallowed out and the ball does not move. I'm stumped?

 

[countrybumpkin]

Will the ball slide side to side on the pin at all, if not try heating the ball a bit and then tapping on the arm to get the ball to slide. Once you get it loose then you can work on getting the pin free, take the bolt out and try tapping on the pin ear and see if you can get it to rotate in the bore, if so it should start to loosen up. Just go slow and easy so you don't take a chance on breaking the case.

 

[rbargeron]

Yep. Kubota dealer confirmed its a blind hole and does not extend into brake case. Said they would probably have to cut it off with a torch and then burn the remainder of pin out of blind hole in brake case........

Have they done this successfully before? I'd exhaust the possibilities of welding on a lever or pull-pin before letting anybody try cutting it out with a torch. It takes good skill to melt a steel pin out of a cast iron hole without damaging the hole. Cast iron melts around 2000F but steel is around 2500F. Just saying.

Do you really need to take off the arm? If the looseness is the issue, get someone to reduce the "wallowed out" clearance by adding some weld metal to the arm. It won't be elegant but it will be strong.

 

[Grandad4]

The factory pin has an ear with a hole that allows the pin to be secured to the case with that bolt shown in your photos, as bumpkin says. The pin itself is not threaded and simply slides into the two holes. It looks to me from your pictures as if the ear is no longer on the pin or the original was lost and a simple straight pin was used to replace it. If that's true, there may be more than just corrosion holding it in place; someone may have welded the thing. Here are the part numbers for the pins and that bolt, if and when you can get the old ones out of there:

Lower link pin: TA040-39412
SEMS Bolt: 01133-5120

Looks like that 3710 has had some hard use. Good luck with your repairs.

 

[Leejohn]

If arms must have to come off. Then put a good tack weld on the arm and ball. Remove the bolt that is holding pin in, move arm up and down to make sure pin is loose. Then put bolt back in then move the arm up and down to get ball loose from pin. If you put some weight on the 3pt then you could use the hyds to do the work.

 

[bdhsfz6]

Yep. Kubota dealer confirmed its a blind hole and does not extend into brake case. Said they would probably have to cut it off with a torch and then burn the remainder of pin out of blind hole in brake case. I tried some heat not red hot and nothing. Tried Freeze Off penetrator and nothing. Been soaking with pb blaster for 3 days and not budging. It appears the ball is froze onto the pin, cause the arm moves freely, is wallowed out and the ball does not move. I'm stumped?

I had a similar thing happen to my L3010 a few years back. I got it out using the idea suggested by countrybumpkin. I got the ball to slide on the pin by soaking it overnight in Kroil (I prefer it to PB) and wedging a chisel between the ball and case. I worked it back and forth with the chisel alternating from side to side. If you try this, be gentile to avoid breaking the housing. I used an air chisel at low pressure. Once the ball was loose on the pin, I positioned it close to the brake housing. I folded the arm to expose as much of the ball as possible and drilled a 1/4" hole through the ball and part way into the pin. I then tapped a 1/4" hardened steel punch into the hole pinning the ball and pin together. After heating the housing with a torch, I used the air chisel on the lip of the ball while applying twisting action to the punch (be careful not to break off the punch!) I was able to get the ball and pin to move about a quarter inch until it hit the inside housing. This gave enough space to get the air chisel between the pin flange and the outside of the housing. I removed the punch from the ball and after applying more Kroil, was able to work the pin out with the air chisel.

The process is difficult to describe and sounds a lot more complicated than it is, but it got the job done. I was even able to save the pin by filling the drilled hole with hard weld and polishing.

 

[L3710]

thanks for all the great ideas. I think I might try welding the ball to the arm and letting the hydraulics try to move the pin. If I can get the pin to move in its holes I can then cut it off with a cut off wheel and then hopefully remove the two pieces of the pin. I am very Leary about putting too much heat near the cast brake case.

I also tried drilling into the ball as was suggested but could not even get the bit to penetrate in. I will let you know how it works out with pics.

Thanks again

 

[Leejohn]

You might not have to cut the pin, read the 2nd part of my post.

 

[bdhsfz6]

thanks for all the great ideas. I think I might try welding the ball to the arm and letting the hydraulics try to move the pin. If I can get the pin to move in its holes I can then cut it off with a cut off wheel and then hopefully remove the two pieces of the pin. I am very Leary about putting too much heat near the cast brake case.

I also tried drilling into the ball as was suggested but could not even get the bit to penetrate in. I will let you know how it works out with pics.

Thanks again

If you do weld the ball to the arm, be sure to put the weld in a spot where you can grind it off. Otherwise, you'll have a non functional 3pt hitch if you can't get the pin loose.

 

[L3710]

Thanks for all of your help with this project. I used an angle grinder to cut the arm and get it off of the ball and pin. Then I bought kroil online and soaked the pin and ball several days and then put a pipe wrench on the ball and got it to start twisting but not enough to remove it. So I then cut the pin, carefully with the grinder and finally got it all out. The part that was in the blind hole came out much easier than the part of the pin near the Pto.

The pin is narrow on the blind hole side and thicker where the bolt attaches it to the tractor.
Luckily I was able to remove everything without damaging the housing.


Thanks for all of your help everyone! $273 dollars for the arm and 15 for the pin from Messics and I have a useable 3 point again!

 

[bdhsfz6]

Good Job! $283 is a lot cheaper than what it would have cost for a dealer to do it. Thanks for posting the results for others who may encounter a similar problem.

 

[ludlod]

I have the same problem with my L3010.
Need to remove the lower arms for a backhoe bracket, but the pins won't budge.
Just got the tractor recently. Looks like they've never been removed.
The balls slide freely, but the pins are stuck in the knuckles. Both sides.
I've been hitting them with heat and PB Blaster each day, hoping they'll let loose.
Ordered a pneumatic hammer. Hopefully that makes the difference.
Trying real hard not to break the tabs off.
Tried whacking them, using vise grips on the tabs to turn them, and prying under the tabs. Nothing works so far.
The pins on the L3010 are offset from the brake housing. So I might try drilling a hole from the back side of the blind hole and tap them out with a drift.