What should be checked if a gearbox is leaking oil?

Category: Gearbox Selection and Use · 19. question

An oil leak is usually a consequence; before replacing a seal, find what is causing it. Cleaning the housing and running it briefly shows where the oil first appears.

Leak point	Possible cause	Check
Input or output shaft seal	Worn seal, scored or running-out shaft, excessive radial load	Shaft surface, belt and chain tension, seal condition
Breather plug	Too much oil, plug in the wrong position, internal pressure rise	Mounting position, oil level, whether the plug is at the top
Cover or housing joint	Loose bolts, damaged gasket	Bolt tightness, gasket
Fill or drain plug	Loose plug, damaged sealing washer	Plug and washer

Heat also increases leaks: as oil temperature rises, internal pressure rises and seals harden faster. So housing temperature should be monitored together with the leak. Lost oil should be topped up with the same type of oil before the gears run dry.

Send the motor power, speed, mounting type and quantity on WhatsApp. If you are replacing an existing motor, you can also send a photo of its nameplate.

Buy Electric Motors Ask on WhatsApp

Other questions on this topic

1. Should I choose a worm gearbox or a helical gearbox?
2. What is the difference between bevel-helical, foot-mounted helical and parallel-shaft gearboxes?
3. Should I buy the gearbox together with the electric motor, or can I use my existing one?
4. Does a worm gearbox hold the load by itself, can it replace a brake?
5. How do I choose the gearbox ratio?
6. What happens to the output speed if I fit a 1,000 rpm electric motor to the same gearbox?
7. What can be done if the output speed I need does not match the standard ratios?
8. How do I find the gearbox ratio from a conveyor belt speed?
9. How is gearbox output torque calculated?
10. What is the service factor of a gearbox and why does it matter?
11. What electric motor power can be fitted to a gearbox?
12. Is it a problem to fit a more powerful electric motor to a gearbox?
13. Why might two gearboxes with the same output speed not be interchangeable?
14. How do I check the IEC flange match between electric motor and gearbox?
15. What do radial and axial load mean on a gearbox?
16. Why does the mounting position affect the gearbox oil level?
17. When are a hollow-shaft gearbox and a torque arm used?
18. What oil goes into a gearbox, and when should it be changed?
19. What should be checked if a gearbox is leaking oil?
20. Why is my gearbox noisy?
21. Why does a gearbox get hot, and when is it a problem?

Gearbox Selection and Use: Frequently Asked Questions →All frequently asked questions →