Hi, Can you someone tell me how the boom extends on a grove 66A manlift? In other words how does it work mechanically? Iam getting a lot of shake when i get out toward the end of the extension. This lift sit in a field for years without being used so iam hoping its just something that needs greased. I have greased the boom itself but that didn't seem to help any.
Hyd cylinder extends 2nd boom section. Chains and pulleys are used to extend and retract 3rd section. Usually just greasing the bottom of the boom isn't enough. It probably needs grease on the rear upper wear pads of each section. These pads are inside the boom so you have to go through one of the holes in the boom and grease the tracks the wears pads ride in. If that doesn't fix it the chains may need tightened.
Not saying you are doing it but a number of times I have seen folks new to a hydro pull a lever and try to run a function using throttle control. It makes things jump and shake like you describe. Hydros should be run at governed RPM and the controls feathered to control speed of function. Old friction hands were good at trying this when stuck in a hydro.
Thanks Knepptune. and thats a good idea about tightening the chain. I actually found the wear pads this weekend. There just brass pieces with a plastic bushing up under them. It didnt look like they rode in tracks though, it looked like they just pushed against the boom, there were allen screws behind them that tightend them up. There were one midway on each boom, then they are on each front section of each boom. My wife actually noticed the holes lining up on the boom and then came the pulley, so we got that greased. tighting up the chain looks pretty straight forward, i seen two nuts on the top of the boom. it does fine till its about half way out then it starts squeeking and it gets worse as it gets out extended all the way, then when you go to pull it back in, it jerks a couple of times and squeeks, like fingers on a chalkboard. this is a low hour machine, it only has about 2200 hours on it.
Hey old iron, there is no external throttle control on this machine, it speeds itself up automatically ever time you move a joystick or toggle switch. probably be smother for sure if you could control it though.
Makes sense. They probably had to do that to keep the old friction guys from trying to work them at idle.
Ye the pads don't ride in a track. You can usually see where the wear pads ride. I just referred to that as the track. The other thing to check is to make sure the bolts holding the wear pads in are not to long. I've seen plenty of wear pads that are worn down to point were the bolts holding them are making the contact. This is usually easy to see as the bolts will dig in and wear grooves into the boom. If you have all the wear pads greased well and it's still screaming it's making metal on metal contact somewhere. Being that it starts once the boom is halfway out I'd look at the rear upper wear pads pretty closely. One thing I've done on machines that haven't seen boom grease in awhile is to run the boom all the way and then set it down to to take the pressure off and then actually get some grease on the top of the wear pads. DO NOT PUSH DOWN HARD. JUST ENOUGH TO GET A LITTLE SPACE TO GET A LITTLE GREASE IN THERE.
thanks knepptune, iam still learning alot on this machine. When you say "rear wear pads" are you referring to the pads that are just inside the portion of the boom that doesnt extend out? Its got what appears to be some pads on the side of that portion that require a 1" i believe hex wrench which i dont have but iam begining to wonder if maybe these are too tight. when its all the way that last 3' or so is when it goes to jerking a bit also.
No. If you picture the boom extending imagine where all the pressure is. Obviously the bottom wear pads and top wear pads. Each section that extends will have a wear pad on the top at the very back of that section. Those are the ones that rarely get grease. The pads on the side only control how much your boom flops side to side. Like the machine stops swinging and the boom keeps going for a few feet. Most of the time if it swings back and forth a lot the swing motor gears may be worn. If when you let off the controller it keeps swinging for a few feet then whips back it's the swing motor gear. Those can usually be shimmed to take up the clearance. If when you let off the controller and it keeps going for a few feet then stops and doesn't whip back its in the controller.
makes sense knepptue, i will give it a shot and try and get some grease in there and see if that takes care of it. as for the swing, it just drifts a bit after i let off the controller. Sometimes a few words from someone more knowledgeable is all the motivation we need though to get er done. Iam just a little nervous on taking that thing apart without a breakdown. We did pull the boom cylinder out and got her rebuilt though. that was interesting. parts from minpar are through the roof. This is not a commercial machine, me and my wife are just using it to build our house, and then I will pass it on down the line. I wil try and post a picture of it latter on today.
swing motor pics, and an unknow device? iam curious what this device is in the bottom of the machine, and what the two turnbuckles are for? (bottom pic) Dont mind the hydraulic oil down their had a hose blow out that had to be replaced for the drive wheels and it sprayed everywhere.
That's your hyd swivel. It's what allows the machine to swing round and round and still get fluid to the lower for your drive and steering. The turnbuckles are to keep the can from spinning along with the upper. Google hydraulic swivel cutaway if your not familiar with what that is. A picture is worth a thousand words on that
ahh, makes sense knepptune. thank ya. So when can I expect you over to shim those gears up for me to cure that side drift iam getting
I'll head that way in the morning. Lol
lol, ok let me know what time and Ill get the grill fired up. Well feed you good!