What to know about the Differential Output Seal:
Your vehicle’s engine produces power and conveys it in a straight line through the crankshaft into the transmission. The power that comes through the transmission is in the same straight line as the engine, yet in some way needs to change 180 degrees to power the wheels. The differential is a device in your vehicle that alters the direction of the propulsion from a longitudinal orientation to a lateral one, and it can also provide a fixed gear ratio change.
The differential contains a pinion gear and side gears that rotate in fluid to solidly transfer the power 180 degrees. Axle shafts run from the differential to each wheel in a couple different designs, yet each requires a way to contain the oil inside the differential assembly. The axle shaft runs through an output seal in the differential that lets the shaft to spin without losing the greasing oil inside. If the axles seal leaks and the fluid escapes, the differential won’t be correctly lubricated and the gears and bearings can overheat and seize, causing extensive damage and rendering your vehicle unsafe to drive.
Facts to Note:
A differential doesn’t have a dipstick to check fluid level in most instances. If there is a leak present, it is nearly impossible to know how much fluid remains.
How to Fix:
The differential output seal is confirmed that it needs to be changed. The vehicle is lifted and supported on jack stands.
The CV axle is removed and faulty differential output seal is removed using a seal removal tool.
The new differential output seal is installed using a seal installer then the CV axle is reinstalled.
The differential is refilled tested for leaks. The vehicle is removed from the jack stands.
The vehicle is road tested to ensure proper operation of the differential output seal.
The differential fluid needs replacement at regular intervals, usually around every 25,000 miles. Have the differential output seals examined for leaks at this time, and if during any other regular maintenance inspection an output shaft seal is found to be leaking, have it changed by one of your expert technicians.
SEE TOO:WHAT IS A WHEEL SEAL REPLACEMENT
Common symptoms indicating you may need to change the Differential Output Seal:
Fluid leaking onto the ground under your vehicle
Loud whining or grinding noise that increases with speed heard when driving
Importanceof this service:
The differential output seal is essential to the lubrication of the internal gears in the differential, though most leaks start out small. If you have just noticed or been notified of a small leak, you have some flexibility in timing to change it. If the differential leak is major, have it repaired soon to avoid additional internal damage.