Woods BH80X - broken cylinder end

[westbrooklawn]

I was digging out a 10" stump with my Woods BH80X (done it a hundred times before), when suddenly BANG!... the cross tube on the cylinder end of the dip stick cylinder had broken off. The weld didn't break, but it actually pulled a plug of metal out of the cross tube. I am thinking I can clean it up, bevel the edges some, and weld back together with some 6011 root, and then several passes with 7018 to build the weld wider and thicker on both the crosstube and cylinder end... I would be welding to the existing weld on the cylinder, because if I grind it off, I would loose the mating surfaces on the cross tube... (see pictures). What do you knowledgeable welding and hydraulics folks think? One consolation is that I surprisingly found I can buy the whole cylinder for around $230.

 

[JJZ 109]

I think I'd spend the $230 on a new one and then try to get the other one repaired for a spare.

 

[Chilly807]

You can try welding it back, the problem you'll likely have is distortion of the bore after welding, enough that the pin won't go in.

If it was me, I'd try to find a heavier walled piece of pipe with the ID smaller than the pin. Remove the old residue on the rod end, then weld the new pipe in place and drill and ream it to finished size afterwards.

Anyway, if you weld the old one back first there's nothing to lose by trying, just some time. It may work. If it doesn't, then try the new pipe, last resort is a new cylinder.

Sean

 

[westbrooklawn]

Chilly - I thought about that, but the pin isn't a real tight fit, so I don't think it would distort enough to keep the pin from being inserted. If the weld broke through to the inside of the tube, that could be a problem, but I thought I could possible grind it out with a die grinder and stone, or drill it with a hole saw.

 

[Chilly807]

It's worth trying, I think if you have enough heat to get a good weld the round pinhole will turn into an egg shape. I haven't had much luck with thin walled shapes, but I'm not exactly a pro welder either.

Sean

 

[RickB]

You can try welding it back, the problem you'll likely have is distortion of the bore after welding, enough that the pin won't go in.

Sean

Gee, wasn't that pin boss welded on to begin with??

 

[RickB]

I am thinking I can clean it up, bevel the edges some, and weld back together with some 6011 root, and then several passes with 7018 to build the weld wider and thicker on both the crosstube and cylinder end... I would be welding to the existing weld on the cylinder, because if I grind it off, I would loose the mating surfaces on the cross tube... (see pictures). What do you knowledgeable welding and hydraulics folks think? .

Excellent plan; go for it.

 

[mguitas]

Wonder if your pressure relief valve is working correctly on cylinder.

 

[westbrooklawn]

mguitas - good question. I know the relief will cut in frequently with the boom cylinder, but haven't noticed it with the dipper cylinder... it just seems to stop moving. I figured the relief was at one spot for all the cylinders, so if it was working for one, it was set right for all?

 

[DJ54]

In order for that to pull out, wouldn't you have been pushing with the end of the stick..??

That, or you pulled yourself back, breaking the pivot point of the stick over center, causing a pull factor on the end of the cylinder, when stopping suddenly, and the weight of the tractor exerting extra force in that direction..??

You'll find you will get more pull/breakout force setting closer to what you are trying to dig or pull out starting with the stick at almost a verticle angle to the ground. You get more force, once the top of the stick goes past center of verticle. You may scoot yourself back easier, but eliminate some of the rocking back over center, stopping suddenly, and exerting a sudden opposite force on the top end.

Im thinking that would be more the cause, than a pressure relief sticking. But I've been known to be wrong before...

Just hate to see you break something @ $230.00 a pop...!!