Best way to shorten cylinder rod?

[etpm]

On my Yanmar YM2310 is a Bulldog 285 FEL. The cylinders that roll the bucket are too long. Actually, the rods are too long. The bucket will not roll back as far as the Bulldog specs show. When fully retracted the rods stick out about 3 inches farther from the cylinder than they should. There is about 3 inches of exposed rod. I have never seen this before. Just to check I disconnected the rods from the bucket and they will still not go in any further. Plus, when the rods are disconnected the bucket can be rolled back by hand to where the Bulldog spec sheet says it should.
I can see two ways to shorten the rods. I can take the ends off of the cylinders, pull the rods out, unscrew them from the piston, shorten and re-thread the rods, and then re-assemble. I don't really care for this option because the cylinders don't leak now and I don't know if I can get new seals if I damage any.
The second option is to extend the rod all the way out of the cylinder, cut the end off, shorten the rod, and then weld the end back on.
I have the equipment and skill to do either option.
Opinions? Other options?
Thanks,
Eric

 

[4570Man]

I’d take the cut and weld option because it’s faster, easier and doesn’t require taking the the cylinder apart.

 

[ptsg]

I second the cut and weld option. Extend the cylinder, protect the chrome well, cut and weld. You know, use that technique of measuring once, cut two times, figure out that it's now too short, so you then add some material and hope it's the right length. Repeat till you get the desired results.

Just shortened a cylinder this week, but it was a lot more involved as I actually reducing the stroke of it as well as changing the ends.

 

[LD1]

I'd do whatever your most comfortable with.

A third option...would be to move the base pin rearward. That may be more difficult.....or if the pin mount area has sufficient plating.....it may be as simple as drilling a new hole and repositioning the cylinder.

Bit the options you listed, cut and weld is fine if you trust your skill. Bevel toe rod good. And protect the chrome as mentioned. Masking tape wrapping it, tin foil, wet rag, etc

if you have a lathe....the disassembly, cut, and rethread isn't hard either. But it's not as simple as just cutting and rethreading. Usually the threads that go through the piston are alot smaller than the rod so you DO need a lathe to turn it down

 

[denchen]

It's hard to say without looking at the problem. I would be looking at leaving the ram alone if I could, and try and see if I could get by and weld a pair of plates with a new pin hole onto the existing fittings. So the hole is futher away from the ram.

 

[npalen]

There could be a "floating" spacer inside the barrel that is keeping the piston from fully retracting. This could be checked by doing some outside measuring and guessing at and allowing for the thickness of the piston.
Ive seen these spacers previously but in the rod end of the barrel to limit the extension of the piston and rod.

 

[etpm]

Thanks all for your replies. I do have a complete machine shop with 4 welding machines as well as the skill to use all the stuff. I thought about moving the cylinder mounts but that would require welding on plates and changing the cylinder angle. I also thought about a really thick piston or some sort of internal stop but that's not the case. So it looks like the cut and weld option is the best. In the past when I had to weld close to chrome plating I wrapped the chrome plated rod with a wet rag. It worked very well. I'm gonna use stainless rod when I TIG weld the parts because I'm not sure of the piston rod alloy.
Eric

 

[Torvy]

Drop the tractor off at my place. I'll PM the address.

Buy one you like with the rods set the way you want. Win-win!

 

[1BADDZL]

I would not use stainless filler to weld it. Most rods are alloy steel with a thin chrome plating on them. Use something like 70-S6 for filler. I normally mig weld cylinders and rods when I build/modify them.

 

[RobertC]

Before you cut the rods be sure you will still have enough extension to fully dump the bucket. Adding travel on one end reduces it on the other unless the cylinders can extend past their current stops.