I got my 06 F150 stuck the other night in some sandy mud. It sunk down to the gear boxes and wasn't moving! It had to set over night and then I got my tractor the next morning and we pulled it out.
Now I've noticed no problems but a buddy told me that I NEEDED to take the "pumpkin" covers off and drain the oil then fill it again. He said that when you leave them sitting in mud/water that sandy water will leak through the seal around the cover and get into the gears causing big problems.
I think MAYBE back in the 70's, 80's and 90's this could have been a problem but seriously on a 06 model do I need to worry about this? Do I really need to go through this???

 

If it was submerged in water (especially over night) I'd probably take the precaution of checking the differential for contamination. It's not big money to do so, and it could prevent a much more expensive repair down the road.

 

its more so the vent tube. diffs are vented, and the hose runs up higher. if you were driving around in water and such you might have gotten it wet. ive never heard of it seeping into the diff, but its not hard to check. just pull the fill plug (the top one) and stick your finger in it, see if it looks like gear oil or if it lookslike a milkshake.

 

The rear end in your '06 is the same rear end that Ford has been using for decades... other than moving the shocks from inbound to outbound, it's still the same axle.

So yes, just for sake, drain and fill it.

It's very easy to do and costs less than you think to do it yourself.

In fact, I'm going to do mine this summer...

 

The diff cover is sealed with silicone, there's no way water is going to seep in. The only way water will get in is if it's high enough to come in through the vent tube.

 

Yes they are.

However, I've seen where the vent tube seal isn't sealed well and somehow water fills the transfer case.

 

Agreed, changing fluid is cheap insurance.

 

Water was not standing over the box. Mud was about 2-3" up the sides over night. I'm not familiar with the "vent tube" Is that easy to find?

 

vent tube is on the drivers side, it comes up through the brake T junction

 

i'd change the fluid, for the time it takes..

 

you only need to change the fluid if their is water in it...pull the fill plug out and dip something in the fluid. If it looks milky change it.

 

agreed

 

Exactly. If it's getting close to the mileage where it needs to be serviced then go ahead and change it. Otherwise, if the oil looks good don't worry about it.

 

at 55k miles. At what mileage do they "need" to be done?

 

when your axle seals start to leak ...im just saying that because its rare to get to fords recomended interval of 150,000 and not need axle seals. Most people do it sooner for peace of mind. Its your choice.