How to Check the Gear Oil on a Jeep YJ

The front and rear axles on your Jeep Wrangler YJ contain gear oil that lubricates the bearings, protects and cools the gears and conditions the seals. Checking the oil level in the axles needs to be part of your maintenance routine. If the oil level is low and not addressed, you may do hundreds of dollars worth of damage to the axle in a very short time. Replace the oil if it is dark, gritty or has an odor to it for best performance.

Things You'll Need

• Oil drain pan
• Socket set
• Ratchet

Instructions

1. Park the Jeep on a level surface. Chock the rear wheels with a block or large rock to ensure the Jeep does not roll while you are under it. Do not raise the Jeep with a jack. This will alter the angle of the differentials, and the oil level will not be accurate.

2. Slide under your Jeep and locate the fill plug on the rear of the front axle housing. Position a drain pan under it to catch any drips and remove the plug from the hole with a socket and ratchet. Insert your finger into the hole. If the oil level is at the bottom of the hole, it is full. If you cannot feel the oil, it is low and needs gear oil added to the differential.

3. Replace the fill plug into the axle housing, then turn it clockwise with a socket and ratchet to tighten it. Move to the rear of the Jeep and locate the fill plug on the rear axle housing. Repeat the same process, as you used on the front, to determine if the gear oil is low. If it is low, add oil to the differential.

References

• "Jeep Wrangler Factory Service Manual;" The Chrysler Group, LLC; 1989