Kubota Hydraulic cylinder with broken piston rod

[ejnichol]

They did something to turn it down attempted threading and then shoved a 14mm nut on it. They knew it wasn't r/r serviceable and so they could only offer welding nut on.

That picture is of it as it came out of cylinder.

 

[ptsg]

They turned it down attempted threading and then shoved a 14mm nut on it. They wasn't r/r serviceable and so they could only offer welding nut on. That picture is of it as it came out of cylinder.

Ops. My bad. Forgot the picture was before the machine shop ordeal.

 

[Mike1955]

I know you said it's hard to find a good shop, but try find another shop that could go away with the threaded section (leaving just enough diameter to center the piston) and drill and tap for a good quality bolt.

That would be a $20 to $30 job on my shop.

Id be willing to drive 100 miles for a good independent shop. Kubota is just to expensive. It isn’t that complicated but experience is worth a lot. Just my two Pennie’s worth!

 

[ejnichol]

Just for reference, I machined the cylinders on my loader myself. All 4 of them, rod, piston, barrel, ends, etc. Just for the rod, I paid around $90 and around $85 for the barrel material. I could machine a brand new rod for your machine for around $120 easily and still made a good profit.

The challenge is finding a competent shop that could get me back to work for 150.00 or less. Then there's the total time commitment. I 've spent 6-7 hours in time just talking and traveling with two shops just to figure out that who the qualified shop might be.

Time factor of getting it back to work and minimizing cost.

I ended up welding 14 mm nut on it. Welding or center tapping existing rod and bolting were only ways to deliver strength need from remaining mass. Finding a shop to center tap, what it would cost and time to do all this and get it back to work moved me to weld.

After 6-7 hrs of digging with back hoe its holding up fine. If it were to break off again then I'd order new parts. I needed to get on with the work at hand.

Thanks for taking time to comment as this has been an interesting learning experience.

 

[ptsg]

The challenge is finding a competent shop that could get me back to work for 150.00 or less. Then there's the total time commitment. I 've spent 6-7 hours in time just talking and traveling with two shops just to figure out that who the qualified shop might be.

Time factor of getting it back to work and minimizing cost.

I ended up welding 14 mm nut on it. Welding or center tapping existing rod and bolting were only ways to deliver strength need from remaining mass. Finding a shop to center tap, what it would cost and time to do all this and get it back to work moved me to weld.

After 6-7 hrs of digging with back hoe its holding up fine. If it were to break off again then I'd order new parts. I needed to get on with the work at hand.

Thanks for taking time to comment as this has been an interesting learning experience.

I totally understand. Not everyone is right up close to a good shop, which can make it an interesting experience indeed.

At least you got it going again so you can keep doing your stuff. Plus you gathered some ideas for the future.

 

[ejnichol]

Id be willing to drive 100 miles for a good independent shop. Kubota is just to expensive. It isn’t that complicated but experience is worth a lot. Just my two Pennie’s worth!

Yea there prices are too much. I would have liked to just order new rod and nut but just cant justify at this time.

 

[pmsmechanic]

Obviously the nut isn't going to turn off again. I think you've made a perfectly acceptable repair under the circumstances. And if you need to disassemble the rod for repairs I would take it to a lathe and machine the weld off and re-weld once repaired. $400 is $400!

 

[WranglerX]

Seems to me a really good hydraulic shop or "machine shop" could do a weld buildup in threaded area and then chuck it up in a lathe and turn it down to factory specs (diameter) and then cut new threads .... End process should look like it never ever had a problem.... But then it's all about the shop you find and the quality of work they do at a cost you find acceptable.......

 

[4570Man]

If you haven’t already screwed up the cylinder barrel and contaminated the system with metal shards you dodged a bullet. I’d do a careful inspection to make sure that’s not happened and buy a new rod and go on.

 

[4570Man]

Seems to me a really good hydraulic shop or "machine shop" could do a weld buildup in threaded area and then chuck it up in a lathe and turn it down to factory specs (diameter) and then cut new threads .... End process should look like it never ever had a problem.... But then it's all about the shop you find and the quality of work they do at a cost you find acceptable.......

I don’t think a good shop would do that repair. The rod already broke once under the optimal conditions. A weld will compromise the heat treat and make the rod weaker than it started.