The answer to this question depends upon several factors. You must carefully consider all factors before making a decision to install a spinner knob on the steering hand wheel of your forklift truck(s).

In general, safe operation of a forklift truck requires that all steering maneuvers be performed with two hands on the steering hand wheel and that movement of the hand wheel must be performed in a slow and smooth manner.

Sharp or hard turns can create an unsafe unstable condition which can result in a lateral tip over accident. Likewise, coming out of a turn and straightening the wheels too sharply can also create an unstable condition and result in a lateral tip over accident.

The best driving techniques for safe operation are performed with two hands and no spinner knob on the steering hand wheel.

• Why do you want to install a spinner knob and is this necessary for control and safe operation of your truck?
• Does your company have a policy governing the use or non-use of steering hand wheel spinner knobs?
• Does your forklift truck have the type of steering gear that allows for safe operation of the truck with a spinner knob installed?
• Does the manufacturer of your truck approve the use of spinner knobs on your truck?
• Can you install a spinner knob according to the OSHA and ANSI Standards?

Answer = NO
If your truck has a mechanical steering linkage connecting the steering wheels to the steering hand wheel, then you cannot use a spinner knob on the steering hand wheel. Even if you have power steering with a booster cylinder or power assist hydraulic cylinder, if there is a mechanical linkage from the steering gear box to the steering spider on the steering axle, and to the wheels, you must not install a spinner knob on the steering hand wheel because when the steer wheels hit something on the ground, the shock is transmitted through the mechanical linkage to the steering hand wheel, causing the hand wheel to "whip" or spin in an uncontrolled manner. The operators hand, wrist, or arm can be seriously injured by the spinner knob.

Answer = YES
If your truck has a hydrostatic power steering system connecting the steering hand wheel to the steer wheels via a hydraulic fluid circuit, then you may install a spinner knob on the steering hand wheel. Typically, these hydrostatic systems have built-in hydraulic shock absorbers to prevent the road shock of a wheel hitting something from being transmitted back to the steering hand wheel.

Before installing a spinner knob(s) on any truck that was not originally equipped with one when built by the manufacturer, you must contact the manufacturer for written approval.

ANSI B56.1
Part II For the User
4 General Safety Practices
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• 4.2.1: "Modifications and additions that affect capacity or safe operation shall not be performed without the manufacturer's prior written approval. Where such authorization is granted, capacity, operation, and maintenance instruction plates, tags, or decals shall be changed accordingly."

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Check the operator's manual, service manual, and the manufacturer's policy regarding attachments and accessories for your truck before installing spinner knobs. And, contact the manufacturer for written approval and instructions for spinner knob installations.

ANSI B56.1
Part II For the User
4 General Safety Practices
.
The following applies to most sit-down rider trucks.

• 4.2.8: "Where steering can be accomplished with either hand, and the steering mechanism is of a type that prevents road reactions from causing the handwheel to spin (power steering or equivalent), steering knobs may be used. When used, steering knobs shall be of a type that can be engaged by the operator's hand from the top, and shall be within the periphery of the steering handwheel."

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The following applies to stand-up rider trucks.

• 4.2.7: "Where steering must be accomplished with one hand using a steering handwheel, a steering knob(s) or equivalent shall be used to promote safe and effective operation. The steering handwheel and knob configuration shall be of a design that will minimize the hazard from a spinning handwheel due to a road reaction feedback, or the steering mechanism shall be of a type that prevents road reactions from causing the steering handwheel to spin. The steering knob(s) shall be within the periphery of the steering handwheel."