Ok, so I have an 04 f150 fx4 4x4 supercab with 5.4. lately ive noticed a burning smell from the rear end and kind of ignored it untill ywsterday. I layed under the truck and the smell was coming from the passengers side rear wheel. The wheel and brake were absolutely covered in thick black fluid. So i took it to my mechanic. He looked at it and said something about it being a differential seal or gasket or something. I wasnt really listening as well as i shouldve because i was so pissed that it was broken! He also pointed out that the other rear tire was doing the same thing and it was starting to have fluid on it as i was staring at it! He said that i need to have it fixed asap to avoid more serious damage. So im taking it in on monday. Does anyone have any idea what this could be? Is it as serious as it seems? The actual transfer case isnt wet or leaking at all. Just behind both wheels. I dont have a ton of cash and ive already spent $700 to replace the head gaskets in december. I may even attempt it myself if i can get some advice. Thanks in advance!

 

Ouch. Relax, not as bad as it sounds. Here ya go. https://www.f150online.com/forums/ar...lots-pics.html

 

might want to look into the TSBs of your model year. I know the 04 year had a problem with the rear end.

can't find the thread it was in but might be worth a gander to see if it fits what you are experiencing.

 

Wow! may be a little too much for me to tackle! I know this may sound ridiculous, but what would happen if i didnt get this fixed right aay? Is this as serious as it seems?

 

I would recommend ASAP. The rear end depends on "splash" lubrication for the internal components. With the fluid leaking, you are losing lube. The more you lose, the hotter the axle assembly operates, and a $400 repair now will turn into a $1200+ repair quickly.

 

When my right axle seal leaked in my 2000 F150, I replaced it my self. I believe the new seal was around $3.00. I also had to drain and replace the diff lube which came to about another $50. It is a very simple operation and doesn't take long.

Of course you need to clean the brake rotor and replace the brake pads if there is oil on those.

I would also check the axle housing vent to make sure it is relieving the pressure when the axle heats up. If this vent stopped up the new seals would also leak.

 

Ok. Thanks guys. This kinda stuff always happens at the worst times! But its awesome getting some insight from other f150 owners! Thanks again!

 

Yeah, it's definetly a case of "an ounce of prevention" vs. "a lb of cure" here. Not to mention that oil on brakes is NEVER a good idea. It's a safety issue IMHO. Just get it fixed. You'll feel better.

 

Easy job better now than later like said

 

Ok so I got the truck fixed....new seals, bearings were fine. The mechanic even cleaned all the oil off my brakes so i didnt have to replace them. changed the dif fluis and rotated the tires....heres the best part. Drum roll please......All for a whopping $190! I was shocked! He owed me a favor but i thought i was looking at over a grand. Sound like i got a good price?