Case 580 Boom Lock

[Archie Dunbar]

I have read on the forum about the boom lock and watched the Youtube videos. By backhoe is kind of loose. There is play in all the bushings that I can see when it is working. Also as I mentioned in another thread, if I select down boom, it falls rapidly. I am thinking that the rapid falling boom also makes locking the boom even harder. I have managed to get it to lock but it is not a graceful thing. It happens just as in the video, raising the boom with full throw and rapidly moving the boom lever to full down as the boom rod is just reaching full retraction. When this maneuver "succeeds" it is not gentle and just as in the video,

, the boom slams into the tower. Well, after one of these episodes I noticed that the boom lock spring was broken. I tried to bend a new hook in the spring but could not get it reinstalled. Does anyone know if there is a special trick to installing this spring?

 

[Coy Lancaster]

Get you a new spring for one because those things are tough when they're the right length. I always hooked in the lock and then the swing tower point. The trick is run engine just above low idle and when boom comes all the way up and bounces just a bit reverse the lever.

 

[Archie Dunbar]

Thanks

 

[RDC_580C]

It will take some practice to get the timing and all right, so expect it to slam in there a few times until you do, and even after you get it to happen all smooth as silk your first time, the very next one probably wont go that well.

Have you Stabs down, and at least 3/4 throttle. I personally keep the Dipper and Bucket curled when I go to lock the Boom. Raise the Boom quickly, then (and this all happens within a second or so) right before it gets to the point where it's going to stop coming up, center the lever and let the momentum carry the Boom up, back and over center, at which point you'll push the lever forward (boom down) to get it to come all the way back into the lock position. You shouldn't have to jam the lever full throw down, as that for sure will slam it back into the lock position, but just feather it (push it 1/4 to 1/3 of the way) and it will ease back into the lock position. Just takes some practice, and once you get the hang and feel for it you 'll be able to do it smooth and easy so that all you'll hear will be the click of the lock, or at the worst a much more tolerable feeling of the boom just settling into the lock position versus that slam where you feel like it's going to wind up in you lap or pound the machine into pieces.

 

[Archie Dunbar]

RDC_580C Thank you, that was the best explanation I have heard yet.

 

[RDC_580C]

Welcome. Anyone that has been in one with that Boom design has gone thru learning it, myself included, and like everything else it just takes a bit of practice.

Probably equally as tricky to get the hang of is unlocking the thing so the Boom doesn't drop really fast and give you a couple huge bounces that also can wake you up. It's pretty much just the reverse of locking it. Make sure the Stabs are down, 3/4 throttle and pull the lock lever back. If it will not release, which happens as the weight of the boom can press on it, then feather the Boom down a bit so the Boom comes back toward the machine some, remember it's in the locked position now, so things are backwards until you get it back over center. That will take the pressure off the lock pins and you should be able to pull the lever then. Hold the lock lever back and you go thru the reverse of locking it. Boom up quick and let the momentum take it over center, and then feather the Boom down a little bit. Once you get the hang of that you'll unlock it in more of a smoother motion versus it going over center and stopping real sudden and bouncing a few times.