Can 85w-140 gear oil be used in place of 75w-90?

Using 85W-140 gear oil in place of 75W-90 is generally not recommended, as the two oils have different viscosities and performance characteristics. 85W-140 is thicker, especially at higher temperatures, which can lead to inadequate lubrication and increased wear in applications designed for the lighter 75W-90. Always consult the manufacturer's specifications for the correct oil type to ensure optimal performance and protection.