Water cooled Dana 44

[Arctic Travelller]

Is it normal for my front diff to be filled with water? I didn't think so, but that's what I found when I pulled the cover today to drain the oil prior to departing for Baja. It looks like the water was in there for quite a while, as the cover has a lot of corrosion on the inside. The gears look OK, but I'm not sure about the bearings as I can't see them, but while driving it seems quiet in 2WD with the hubs dis-engaged. That makes me believe at least the wheel bearings are ok. I plan to flush it out, refill and drive for a while in 4wd, then drain again. If I don't get any indication of a problem I'll leave it as is. My hope is that the water sat on the bottom and didn't rust the bearings.

The big question is "How did the water get in?" There is a vent line attached that goes to the top of the engine compartment cover, and I doubt the van ever got submerged that deep. Could it have gotten in past the axle bearings? Does anyone see a reason not to just flush and refill? Thanks in advance...........Arctic Traveller

 

[cwsqbm]

Water definitely gets in past the axle bearings. That's why Unimogs pressurize their axles.

 

[Ozrockrat]

Check the breather is not blocked. If there is no way to allow air in they will suck water through the axle seals when the water cools the metal/air. Given it is a front diff I would probably replace the wheel bearings, flush it out and run it as you suggested. Not as though the front diff sees a lot of work unless you live in sand or snow.

 

[k9lestat]

i concur with the above

 

[Arctic Travelller]

Since the wheel bearings don't make any bad noises, or get hot, I'm thinking they are probably Ok, any other reason to replace them other than an abundance of caution?
I will check the breather though, Thanks....................

 

[r_w]

We always had the same problem in the old John Deere tractors. They CONDENSE water inside any night there is dew or frost, but never get hot enough to cook it back out. Yes, eventually enough to push the oil out the top.

 

[mtbikerTi]

The wheel bearings do not share lubricant with the differential. With the cover off, hubs unlocked, and transfer case in neutral (or preferably driveshaft removed) spin the pinion and see what the bearings in the diff feel like. It may also be a good idea to check the seals in the axle to make sure they're good, as if they aren't that's a great place for water to get in.

 

[Arctic Travelller]

The wheel bearings do not share lubricant with the differential. With the cover off, hubs unlocked, and transfer case in neutral (or preferably driveshaft removed) spin the pinion and see what the bearings in the diff feel like. It may also be a good idea to check the seals in the axle to make sure they're good, as if they aren't that's a great place for water to get in.

Thanks, that's pretty much what I did, and everything looks pretty good. I covered the bearings, scrubbed out all the rust on the case using a wire brush and vacuum, washed it down with brake cleaner, blew it out with air, and refilled with oil. After driving around a bit, I'll drain it again and refill. The question now is, how do I check the axle seals? There is little doubt that's how the water got in, but short of disassembling the axle, can I check the seals? If I have to take it apart, it would be silly not to rebuild it, but I'm hoping since there are few water crossings in Baja, I'll be ok for now.............

 

[mtbikerTi]

If you don't have gear oil leaking out of the ends of the axle then your seals are likely ok. Check the vent and make sure it is working properly and that the line has no cracks or kinks in it and drive it. Worst case you only have 2wd right?