xiongb1

I have a 2004 F150 Lariat Model. 4x4., 5.4L. Auto Transmission.
86k miles. I have this truck for 3 years and it has not gave me any issue at all. I'm very happy with it.

This year I've noticed fluid leaking from the rear diff. It's really strange, the fluid is not leaking right where the diff is at it is actually leaking out of a small hole from the drive shaft. See circle pics.

And then I also noticed leaking from the transmission. See pics. Any ideas of what I'm looking to spend? or how easy it is to do it yourself?

Thanks guys.


[img]https://www.f150forum.com/attachment.php?attachmentid=16615&stc=1&d=12721355 19[/img]

Shiny

From what I can see. It Looks like your Transmission rear seal is leaking.
Should not be too expensive. Rear seal that is it.
Good luck hope it is just the seal.

xiongb1

Yeah. I hope nothing is serious damage. Btw I do have a 21 wakeboarding boat that o haul every summer every weekend to the lakes and river. Didn't know if that would apply more stress on the transmission and rear diff.

blackbetty

When you tow anything it is considered in that "Heavy/off road" use category. I does lead to higher temps and more wear on the drive train and even the motor. More frequent fluid changes are recommended and you should be nearing your 2nd as the first one is 60k and then 30 there on after if i remember correct from the manual.

This probably isnt the cause of the boat and just a seal issue as stated above unless there is a crack or some other damage that is hidden, which is really unlikely.

As far as the diff, i really cant give you any idea, there isnt fluid in the shaft and the input pinion is sealed from the universal so id guess water but not sure there. maybe your parked at a decline and fluid is running out the input pinion seal onto the universal but with out looking i cant tell.

Also your tranny fluid should be a redish heavy fluid, not clear?

xiongb1

Yeah the transmission has a very minor leak. I think it's seeping thru the gasket. The rear diff. is definte leaking thru that area on the drive shaft. It is very strange indeed. Anyways ill have this local transmission shop look at both of them.

RahX

The only thing sealing the pinion there are the splines on the yoke and pinion and the nut that holds the yoke to the pinion. Maybe the nut isn't tight enough? That is a weird place for it to leak.

Shiny

What you can do is, give it a god wash using a degrease. let it dry and drive for 50 or 100 mil. then you will now where it is coming from.

Mike

if the fluid level is fine and theres no drips on the ground leave it be. my diff leak is way more noticable and it even leaves a few drips if parked a long time. its done it for a month or 2 and when i pulled the plug off the side the fluid was right at the top