We generally replace the gearbox oil (Shell Morlina 150) at every 8000 hours. At every other year gearbox is also overhauled. I want to know others experience in this field. Should I continue oil and gearbox replacement like this? We don't have any oil nalysis program for these gearboxes.
Make Amarillo 1712 (80lit oil) 16 gear boxes.

In my previous plant we used to replace the oil (mineral) once a year and usually it was still in good condition. With synthetic this interval could be extended. The other plants were replacing synthetic oil every 18 months.

Perhaps it's better to buy at least portable water & viscosity test kits.

In a previous location, we changed out our mineral oil in cooling tower gear boxes annually until we started doing oil analysis. With the analysis program, we got at least two years out of the oil. What is the condition of the gearboxes you are having overhauled? Is this a circulating system? What kind of filtration is fitted (if any)? If you are getting significant wear in the gears, then change oil to something besides an R&O oil.

Ken Culverson

Actually condition of oil is not consistent in all the G.BS. Some have only discolouration, while others have high moisture (upto 740ppm)and deposits.

Condition of bearings is also varing. Though we can run them upto 3 years or even more (Amarillo Says to replace after 5 years), but we change them every 2 years. I mean half of the gearboxes are overhauled one year and rest in the next year.

Whats your experience with mineral oil Morilna150 and bearings replacement.

One maint manager told me that he doesn't change their G.Bs bearings until they start producing noise.

Yahoo,

I worked in a Petrochemical Plant for 6 years, during that time our Gearbox (Amarillo)overhauls were based on Oil & Vibration analysis. We had some 18 Cells in total and operated these without routine O/H or oil Change. If memory serves me right, we replaced bearings on a couple of G/B but, we had fan blade lamination peeling off after 2 years.

Regards...Rajan