Should You Disconnect Cooling Tower Fan From Gearbox before Removing

Short answer: Yes — the fan should be disconnected from the gearbox *before* removing the gearbox.

But here is the important part:

Here is a high-level explanation (no unsafe step-by-step teardown), because removing a cooling-tower gearbox involves fall hazards, suspended loads, pinch points, and requires trained personnel.

✅ High-Level Explanation

A cooling-tower gearbox normally supports or connects to the fan shaft through:

* A hub and fan shaft seated in the gearbox output shaft

* A coupling or flange connection

* Blade weight + shaft weight resting partly on the gearbox

Because of this:

Removing the gearbox while the fan is still attached is dangerous because:

* The fan’s weight and the shaft’s weight can drop or shift

* You can bend the fan shaft

* The gearbox can jam or crack during removal

* Alignment may be ruined

* It becomes unsafe to hoist the gearbox

That’s why technicians always separate the fan assembly from the gearbox first, so the gearbox can be removed safely and independently.

High-Level Sequence (Concept Only, No Technical Steps)

Here’s what any trained cooling-tower service crew does conceptually:

1. Lock-out/tag-out the system

2. Secure and block the fan so it cannot rotate

3. Disconnect the fan shaft or coupling from the gearbox

4. Support the gearbox with a hoist

5. Remove gearbox mounting hardware

6. Lift out gearbox safely

Again—this is high-level only. The exact method varies by brand (Marley, BAC, Amarillo, Evapco, Liang Chi, etc.) and tower size.

Why Be Careful?

Cooling-tower drive trains are heavy.

Typical fan shaft + hub + blades = 100–1,000+ lbs

Gearboxes = 80–600+ lbs

Incorrect removal can cause:

* Shaft bending

* Gearbox misalignment

* Fan blade damage

* Worker injury

That’s why OEMs require trained personnel or follow the OEM maintenance manual.