Symptoms of a Bad or Failing Front Output Shaft Oil Seal

The front output shaft seal is an oil seal that is installed on the front of transfer cases. As its name implies, the front output shaft seal is responsible for sealing the front output shaft of the transfer case, keeping the gear oil or transmission fluid inside of the unit. The seal is usually round in shape, and made of rubber and sometimes metal, not unlike many other automotive engine and transmission seals. Over time the rubber can dry up and the seal can wear out, which can lead to leaks and other issues. Usually a bad or failing front output shaft seal will produce a few symptoms that can alert the driver of a potential issue.

Fluid leaking from the transfer case

The most absolute most common symptom of a problem with a front output shaft seal is fluid leaking from the front of the transfer case. If the rubber transfer case seals dry out or crack they can leak gear oil or transmission fluid. A fluid leak can put the transfer case at risk of suffering internal damage due to low lubrication. Any sort of puddles, or drips of fluid found underneath the vehicle should be addressed as soon as possible to prevent the possibility of damage occurring.

Hum, whine, or growling noise coming from the transfer case

Another symptom of a problem with a front output shaft seal is a noisy transfer case. This problem usually occurs after the seal has been leaking for a while and the fluid has run low. If the fluid runs low the vehicle may produce a hum, whine, or growling sound from the transfer case, that may be especially pronounced when the four wheel drive or all wheel drive modes are engaged. A noisy transfer case can also be caused by a number of other issues, so a proper diagnosis is highly recommended.

Like most rubber automotive seals, the front output shaft seals will eventually dry or wear out as time goes on. If you find that your front transfer case seal is leaking, or perhaps having another issue, have the vehicle inspected by a professional technician, such as one from YourMechanic, to determine if the seal should be replaced.


Next Step

Schedule Vehicle Drivetrain Inspection

The most popular service booked by readers of this article is Vehicle Drivetrain Inspection. Once the problem has been diagnosed, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. YourMechanic’s technicians bring the dealership to you by performing this job at your home or office 7-days a week between 7AM-9PM. We currently cover over 2,000 cities and have 100k+ 5-star reviews... LEARN MORE

SEE PRICING & SCHEDULING

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Recent Vehicle Drivetrain Inspection reviews

Excellent Rating

(5)

Rating Summary
5
0
0
0
0
5
0
0
0
0

Ben

41 years of experience
1410 reviews
Ben
41 years of experience
Audi A4 L4-2.0L Turbo - coolant system check - Houston, Texas
Ben identified the problem after two other mechanics failed to do so.
Toyota 4Runner - Alternator - Houston, Texas
A+

Kevin

6 years of experience
92 reviews
Kevin
6 years of experience
Subaru Forester H4-2.5L - Vehicle Drivetrain Inspection - Windermere, Florida
Quick and easy.

Eliud

23 years of experience
200 reviews
Eliud
23 years of experience
Ram 1500 V6-3.6L - Vehicle Drivetrain - Snellville, Georgia
Eliud was punctual and knowledgeable about my vehicle. Solved the issue within the half hour

Darnell

19 years of experience
21 reviews
Darnell
19 years of experience
Pontiac Fiero V6-2.8L - Vehicle Drivetrain Inspection - Inglewood, California
VERY PLEASANT AND INFORMATIVE!

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

Related articles

How to Replace a Pinion Seal
A pinion seal keeps oil in the differential and keeps water, dirt, and debris out. A failing pinion seal will leak which can ruin the differential.
How to Replace a Differential Output Seal
Differential output seals prevent fluid from leaking out of the differential, causing the differential to overheat and cause damage to your car.
How to Dispose of Transmission Fluid
Transmission fluid needs to be changed at regular intervals. Old transmission fluid is recyclable. Proper disposal helps reduce overall waste.

Related questions

Antifreeze leaked into transmission fluid
The radiator on your vehicle houses a chamber to cool engine coolant, and another chamber to cool transmission oil. There aren't many points where coolant can come into contact with transmission oil other than at the radiator. An internal rupture...
Van jerked with a clunking sound, transmission fluid leaked
The transmission may have blown out the front pump seal where the torque converter goes into the transmission. This can be due to the transmission front pump bushing is bad or another problem. You have both axle seals that may...
Transmission fluid - 2007 Toyota Tacoma
It is definitely time to have it changed. There should not be any issue with changing it at this point even if it is overdue. Have a local technician, like one from YourMechanic, perform a transmission fluid service (https://www.yourmechanic.com/services/transmission-fluid-service) on...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com