Hey guys,

While backing my boat into a lake with a terrible boat launch, i had to put my rear wheels into the water deep enough to have the rear axle underwater, and my exhaust pipe (with engine still running) was surely close to being under, if not under outright.

Now, normally I wouldn't really care about this, but i just changed my diff fluid the day before and don't really want to pay to do it again. There won't be any water in there will there? According to my "off-roading guide" printed by ford that came with the truck, i should change my diff fluid any time the axle is in water up to my hubs, and im positive it was there for sure.

I've gone through this exact thing before with my last truck and never cared, but it was an older truckwith no where near the value (or emotional connection) that i have with this one.

Any help/advice/stories appreciated

Cheers
Tanner

 

I think you should be alright but I would change it just to be sure. Its going to be in the back of your mind until you take care of it. Plus its cheap insurence.

 

wanna know whats in there after you dip it?
http://cleargearz.com/

theyre spendy and tough. but its pretty cool you can see inside and see exactly whats in there. if you let it sit the water should settle away from the oil and you should be able to spot it.

 

Hello Tanner_F150,

The reason you should change the fluid is that the synthetic oil your axle requires can not absorb water like regular oil can, it just stays in there. It can cause rust in the axle if it sits for a long time. So while synthetic oil is better in many ways it is weak in this area. I would change it if possible.

 

Change the lube ASAP. Remember the old saying, "pay me now or pay me later?"

The water will not only rust everything internally, it will also cause the lube to insufficiently lubricate the ring and pinion by lessening the effect of the GL-5 additive package that was in the diff. lube, resulting in the gearset being trashed along with all bearings and seals.

I see many failures each month that involve water contamination in the lubrication. They are not pretty.

 

If you are going to be dipping the differential in the water it would pay to extend the breather hose. Have a look on the driver side of the axle tube and you will see a fitting that the rear brake lines pass through. It should have a rubber hose attached to it that extends up to the bed cross member. If that hose is missing or cut your differential may have sucked up some water. Cheap, well not that cheap, insurance would be to change the fluid in the differential.

JMC

 

If your exhaust pipe was still above the water, then it probably didn't get high enough to enter the axle. IMO But it won't hurt to change it.

 

Take the fill plug out and stick your finger in. If the oil looks milky on your finger change it. If it looks clean your ok.

Chances are your ok. Several times a year I drive deep enough to get water in the cab and the fluid is ok. Last turkey season I went through water so deep that it got something to do with the door open chime where it would beep constantly. I tried to pull the fuse for the chime but it was on the same circuit as the speedo and the trans did not want to shift right without getting a speedo reading. That was on the 93 I had, haven't had that problem with the 2000 I have now.

I also back a boat in the water over the axle about every other week.

Like the others said verify that the vent hose is good and runs up to the frame. I doubt you got water in, the water would have been in the bed of the truck to get water in.