Synthetics and Multi-Weight Oils. While old-timers may rely on the old standard SAE 90 weight gear oil, newer multi-weight oils, such as Amsoil’s 75W-140 synthetic, maintain their viscosity at ...

As the gears (particularly the ring gear) spin, they pick up the 75W-90 (or whatever weight gear oil you've got in there), and splash it all over the place to make sure the gear teeth don't ...

At the car repair shop, we often hear mechanics mention gear oil and transmission fluid when discussing any fix involving the gearbox -- so much so that many might have started to believe that they ...