* Differential (Rear Axle): The differential is located in the rear axle housing. The fill plug is usually a bolt on the top or side of the differential housing. It often has a slightly different head than other bolts in the area (sometimes larger or a different shape). You'll need a socket or wrench to remove it. Consult your owner's manual or a repair manual for the specific location on your year and model S-10.
* Transmission (Manual): If your S-10 has a manual transmission, the fill plug is usually on the side of the transmission case. Again, consult your owner's manual or a repair manual for the exact location. It might be near the top, middle, or even slightly lower. You will likely need a specialized gear oil pump to add oil to the transmission, as it is generally not gravity-fed.
* Transmission (Automatic): Automatic transmissions in S-10s generally don't have a dipstick for gear oil and are sealed units. They are typically filled and checked by a mechanic using specialized equipment. Do not attempt to service the automatic transmission yourself unless you have extensive experience. Improperly servicing it can cause major damage.
Before adding any gear oil:
* Consult your owner's manual: This is the most important step. It will specify the correct type and amount of gear oil for your specific S-10 model and year.
* Locate the correct fill and drain plugs: Make sure you know which plug is for filling and which is for draining before you start. Often the fill plug is slightly higher than the drain plug.
* Have the correct tools: You'll need a socket or wrench that fits the fill and drain plugs, along with a drain pan to catch the old oil. For manual transmissions, you likely need a gear oil pump.
If you're unsure about any part of this process, it's best to take your S-10 to a qualified mechanic. Incorrectly adding gear oil can damage your vehicle's drivetrain.
