If you are required to add fluid to the transmission on your car, truck, or SUV on a regular basis this condition may be an indication of a worn or defective drive shaft seal. You should conduct a thorough inspection to identify the source of the leak and accomplish the appropriate repairs. If the drive shaft is saturated with fluid the seal is defective and must be replaced to avoid more extensive repair requirements. Insufficient fluid levels have a negative impact on the lubrication process and internal components will be damaged in a very short timeframe. Early detection and replacing a driveshaft seal is a very easy and inexpensive repair that can save the transmission from being permanently damaged and require replacement. This is a very extensive and costly process that can be avoided.
Drive shaft seals allow the shaft to function appropriately and retain the required fluid within the transmission. Depending on the vehicle and the drivetrain configurations these seals are also incorporated into transfer cases and differential assemblies. They are integrated into any component that provides power to the driveshaft. If you own a car or truck with more then one driveshaft and one is defective it would be a good preventive maintenance practice to replace all of them due to the lifespan being similar.