Versalift Aerial Lift Control Head Inspection Guide | USSI Technical Bulletin
Versalift Aerials: Control Head Adjustment & Inspection Guide
Versalift aerials are known for their easy to operate and high-quality upper control heads. One of the greatest features of these control heads is their ability to be continuously adjusted and rebuilt to maintain their factory feel. By periodically checking the below items, it’s easy to determine when your control head may need some attention.
NOTE: For the following tests, the bucket may be positioned near the ground for convenience. The truck must be off, with your organization’s lockout/tagout procedure observed.
Step 1: Inspect the Enable Trigger (“Dead-Man”)
First, check the enable trigger (“dead-man”) for any free play. The green mark in photos A and B indicate where the enable trigger actually starts to move the valve spool.
Photo A
Photo B
These photos show excessive free play in this enable trigger before the spool is actuated, requiring adjustment.
Not only does this lead to sluggish operation, but it also reduces the flow of oil through the control valve that may slow boom speeds. On 4-Axis control heads, any amount of free play in the enable trigger may inhibit operation and should be addressed.
Step 2: Check for Excessive Free Play in the Control Head
Verify the control head does not have excessive free play. The controls should have minimal “float” while in the neutral position. This may be checked by gently moving the control side-by-side, without actuating any of the functions. If noticeable movement in the X or Y axis occurs it may require attention.
Excess Control Free Play Inspection – Versalift Aerial Lift Control Head
Good Control Free Play Inspection – Versalift Aerial Lift Control Head
Step 3: Test Return to Neutral After Function Actuation
Finally, actuate all control functions one-by-one and quickly release the control while the function is being actuated. Verify that the control returns to the neutral position after each function is released. If the control sticks in any position, it may lead to unexpected boom movement during operation; the unit should be taken out of service until the issue is resolved by an experienced Technician.
When to Call the USSI Service Team
If a unit is experiencing one or more of these symptoms, a simple adjustment may be all that is needed. However, if adjustment of the controls does not resolve the issue, the control heads are fully rebuildable, minimizing the cost and down time of ordering and installing a new control head assembly.
Your trusted USSI Service Team stands ready to assist you with these adjustments and repairs.