Skip the auto shop - Our mechanics make house calls

Q: The rear main seal leaking off a '99 F-150 4.6

asked by on

I have a '99 F-150 4.6. The rear main seal has been leaking a little off the truck. It has 310,000 miles. Is it an easy fix? Should I change the transmission seal on it too?

The actual fix of taking the seal in and out once you are there is easy, but the problem is that you’ve got to move the transmission off to get to it.

So, if you are willing to do that, you might as well change the transmission seal while you are in there. Now, I had very good luck with this product AT-205 re-seal. They sell it on Amazon and I buy it all the time.

You pour it in the engine oil or in the transmission oil. It’s a polymer so it mixes with both and it can rejuvenate a bad rear or front main seal. You might just try that first. If you would like help from a professional, a technician from YourMechanic can come to your home or office to find and repair your transmission fluid leak.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  1. Home
  2. Questions
  3. The rear main seal leaking off a '99 F-150 4.6

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Exterior door handle issues

The door handle will need to be installed when the torx is at a position where the handle can be installed and slid forward. Then loosen the torx almost all the way until the lock can be installed and then...

Q: Car not shifting out of reverse

If your vehicle is a standard you might have a problem with a synchronizer inside the transmission. Synchronizers are what allow you to shift from one gear to the next without hearing a grinding sound. Disassembly of the transmission is...

Q: I don't think my car is transferring the antifreeze properly through the radiator or the engine.

Steam or smoke could be due to escaping coolant, if there is a leak, but such could also be due to leaks of other fluids if those fluids happen to leak onto a hot engine part, such as the manifold,...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...