[RalphVa]

I'd only change it if the bottom seal starts slinging oil. This is what I follow on my cars and pickup, too. Have NEVER changed transmission and gear oil in the VW and Toyota. Changed them on the Benz at around 180k miles when the seals started slinging a tad of oil. The change stopped the slinging. About 5 or 6 years later and about 205k miles, changed them again.

Changed transmission oil on my Gravely when one axle seal started to leak. The change almost stopped the leakage.

May have the Toyota's changed this year when it goes in for the state inspection. It is 12 years old and has 149k miles on it.

Ralph