Front axle oil change with Amsoil Severe Gear 75W-90

[IH3444]

If Amsoil fully synthetic Severe Gear 75W-90 oil is used in the refilling of a 4WD front axle, how many hours before the next oil change under regular use?

 

[YanmarFever]

I had an engineer tell me that synthetic oil is best for gear boxes that do not get very hot or have a fast output.
He said that regular gear oil would be just as good.
He mentioned that for a mower gear head it would be fine, but for a front axle I would be wasting my money using synthetic.

 

[LouNY]

Well I guess I'm wasting money, 3 of my tractors have Amsoil Severe Gear in the front axle, and my mower has it in the rear axle. My flail mower, bush hog and snow blower all have it in their gear boxs. The most frequent change interval I've every noticed was at 100 hours from new and others were 400 hours, many have an initial change and no required interval after that.

 

[RjCorazza]

I put Amsoil 75w110 in my past two front axles, and use 75w140 in all of my gear boxes.
Most of the gear boxes get changed on a very loose schedule of every few years. The gear boxes on my diesel zero turns get changed by the book every 150 hours due to the severe service 6-8 hours per day.