The Stovebolt Site Forums The Shop Area Driveline Changing Gear Oil - Frequency

How often should you change the gear oil in the tranny and rear end?

good idea when you first get the truck, after that it shouldn't need changing unless you're using it really hard and missing a lot of shifts

Bill

The average mileage for gear oil is 15k-20k, according to the MSI guidelines. However, you should be able to go at least 50k or more without any problems, especially if you go synthetic.

When it's dirty... sounds like a smart aleck answer but I am serious.

Changed the rear and trans fluid on my '65 C10 because it was "new to me" and I had to change the pinion and an output shaft lip seal.

My wife's '07 Jeep Wrangler has over 100,000 miles. We bought it new and I have changed the rear differential gear lube about every 50,000 miles. The front still has the factory OEM fluids.

It really depends on what duty they see: light, medium or heavy duty use.

My hi-tech method: Unscrew the fill plug, stick your finger in the fluid. If it's coal black, change it. If it isn't and still looks similar to new GL-4 gear lube, let it ride.