Discussion:
Unsafe Boom movement

Hi there, We have a JLG 40 foot boom lift on hire that has what I believe to be a dangerous fault.
When operating the Lower Boom upwards from either the basket or ground controls, the boom will correctly lift UP.
If you then "quickly" operate the toggle from UP to DOWN the Lower Boom will continue to lift UP.
There is a reduction in the upward speed and it does "sound" different but it is going UP with the toggle switch DOWN.
The problem was discovered accidentally, as normally you would let go of the toggle before changing direction from UP to DOWN.
A technician has attended our site and signed it off as OK to use. I don't think so.
The problem does not occur in the opposite direction. So if going DOWN and quickly flick to UP, the lower boom will swap direction from down to up.
I have a short video of this happening.
I know it's unlikely but if you were about to collide with something and threw the toggle down immediately and the boom kept raising it could be catastrophic.
Also I know that the solution is NOT to quickly change direction but I'm just highlighting this issue.

Has anyone had a similar issue and how did you overcome it?

Cheers, Gibbo.
  • Posted 27 Dec 2024 10:10
  • By Gibbo_EWP
  • joined 27 Dec'24 - 2 messages
  • Victoria, Australia
Showing items 1 - 2 of 2 results.
Thanks Mathew,
A JLG tech finally came out to site to inspect and tested the unit. In his opinion it is safe to use despite the uncontrolled reverse action. He had previously adjusted some setting via his programming unit but that's the best he can do. So it's still tagged out of service awaiting replacement from the hire company. Hopefully the next JLG unit doesn't do the same.

Cheers, Gibbo.
  • Posted 18 Jan 2025 13:32
  • By Gibbo_EWP
  • joined 27 Dec'24 - 2 messages
  • Victoria, Australia
Normally just having boom joystick can make operation normal again, I have found bad coils also and the valves sticking causing similar problems...if your renting the machine, the company is liable to repair the problem...If your renting don't feel it's operating properly tell your supervisor
  • Posted 30 Dec 2024 15:11
  • By Matthew_Reed
  • joined 12 Jun'23 - 112 messages
  • New York, United States

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Fact of the week
The origin of "love" as the score zero in tennis is debated, but two main theories prevail. One suggests it's derived from the French word "l'oeuf" (egg) which resembles the shape of the number zero. The other proposes it's related to the Dutch word "lof" meaning "honour" as players might be playing for honour when scoreless.