I have a 2004 JLG 450A II with about 800 hours on it. I mistakenly bumped the bucket against my truck when the bucket was turned all the way to the side. (parallel to the machine) Now the controls to turn the bucket don't have any effect and the bucket just swings freely. Is there some kind of overpressure relief valve I might have tripped? :beatsme Thanks for any help.
I've never worked on a 450A, but given what happened I would be looking for something mechanical rather than hydraulic. If there's a cover over top of where the basket rotate motor is, take it off and inspect the mounting and mounting bolts for broken parts. Try watching while you rotate the basket by hand to see what moves (that's not supposed to). Most of them had a stack of spring loaded clutch discs (about 4" in diamaiter) but if it was adjusted too tight you may have broken something. Atcoequip will know for sure what goes on those machines.
Yeah, would be nice if this one used the clutch disks OFF. The 450A II has an orbital type basket rotate motor. Definitely need to check the six 3/8 bolts in the top of the rotator. They are designed to shear under an impact load. I can't remember if they are grade 2 or grade 5 bolts, but if they are sheared off, do not replace with grade 8 bolts. If it's not the bolts sheared off, more than likely something wrong inside rotator and going to require disassembly. You should go to the JLG website and download the parts manual so you can see what your getting into.
We just sheared the bolts off of a Genie. We were told to use grade 2 bolts so they would fail in case of an accident. Also, we have 2-3 of the orbital rotators if you find you need it. Given what happened i doubt this is the problem but wont air in the rotator cause it not to have any function? Like i say that is a really long shot.
I suppose it's possible. But, how would the air get in there? Also, I would thing operating the control would push the air out and get it operating again. Seems it wouldn't operate for gumper.
I know what ya mean, just trying to recall any time that its happened out on a job. That was the only one i could think of that was easy!
Hey, thinking is all part of fixin.
I thought only Genie was good enough to put downloadable manuals on thier website! Good to know. Thanks for the heads up.
Yup. Don't mean their manuals and schematics are better than Genie though...not much we can do about that eh?
I work for United Rentals.Try looking at rotator bolts .They sould be 3/8 ths .Their shold be six to eight bolts .You don't have to remove basket.Just line up by hand .We have had that happen before in are rental fleet.Use grade 2 bolts. Sometimes you can use a pair of needle nose pliers to remove them.Or you can us a left hand drill bit to remove the bolts .They come out with the drill bit .But if not use a ezeout .Don't use any heat from torch to remove broken bolts. When installing new bolts use flat washer under each bolt head do not use lock tight and torque to 30 foot pounds .The reason you don't want to you use lock is so if this happens again the bolt will come out with ease .
It ended up being the bolts. There were (8), 3/8 bols all of em were sheared off. I drilled em out with a left handturn drill bit and replaced them. The hardest part was actually getting the bucket to line up with the holes so that the rotation was equal on both sides. Ended up being a simple fix. Thanks for all the advice. This forum rocks!
gumper you are welcome any time .Where in jersey do you work and for what company?