Borescope selection for gearbox inspection

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A video borescope lets you look at gear teeth, bearings and the inside of a gearbox case through an inspection port or a drain or fill hole, so you can decide whether a strip-down is needed. The right scope depends mostly on the access, not the brand.

Access: diameter and length

Measure the smallest opening the probe has to pass and the distance from that opening to what you need to see. The probe diameter must clear the opening with room to articulate, and the working length must reach the far side with some margin. Gearbox inspection ports are often generous; drain plugs and breather holes may not be.

Articulation

Inside a gearbox you rarely look straight ahead. Two-way articulation lets the tip bend up and down; four-way, or all-way joystick control, lets you sweep across gear faces and around bearings. More articulation makes it easier to inspect tooth flanks and roots and to find the same point again.

Optics and lighting

• Field and direction of view: forward view for navigating, side view for looking at tooth faces square-on. Interchangeable tips give both.
• Lighting: oily, dark gearboxes need strong, adjustable light at the tip to avoid glare on wet metal.
• Image quality: resolution and depth of field decide whether you can tell micropitting from a reflection.

Measurement

If you need to size a defect (pit diameter, crack length, wear depth) rather than just see it, look for a scope with a measurement capability such as stereo or 3D phase measurement. Say whether you need numbers or images.

Environment and handling

Check the probe's oil resistance and operating temperature, and whether the insertion tube is tungsten-braided for durability. Think about how the scope is carried and powered around the site.

Records

Most maintenance teams need to save still images and video, add notes, and compare against the last inspection. Check how files are stored and exported.

What to send

The smallest access diameter, the reach needed, what you are looking for (pitting, cracking, wear, debris), whether you need measurement, and any scope you already own (manufacturer and model).