Differential Fluid and Hub Seal Fluid

Good evening all from beautiful snow covered Huntsville, TN.

I was recently told by a Detroit Diesel mechanic that Prevost had sold some of their buses with synthetic differential fluid, and some with synthetic hub seal fluid. However, he didn't know for sure what year this started. He said if it was sold with synthetic fluid, I should replace with synthetic when it's time to replace.

Does anyone in POG land know if there was a "switchover year" when Prevosts were shipped with synthetic differential fluid and hub seal oil? Our bus is a 2002 chassis, 2003 Liberty conversion, XL II.

Eric Faires
Huntsville, TN

If they did use synthetic I doubt if it matters when they switched to it. When the differential fluid is due for changing just use synthetic at that time. I think the synthetic I used when I changed fluids was Shell Spirol? I'd have to look.

Do you drive 100k a year? Synthetic oils are great for the high mileage drivers, because of their long term durability. Synthetics have no better lubricating properties than that of convential oils. In most motorhome applications with an annual mileage of 20k or less per year, synthetics are simply a waste of money. Change your differential oil every 24 months. Moisture, not wear is your biggest culprit.
Transmissions, differentials and engines like clean oil, and for my piece of mind, oil that is changed regularly.