kusman

I was reading many posts and articles about water crossings / deep mud crossings and I was not able to find concrete answers to oil changes after mudding.

It is clear that I need to change oil in the diffs every time they have been under water even slightly. The questions I have are about the gearbox and transfer case. Most articles I read are about manual gearboxes and you basically need to change oil there if the car was stationary in water, but what about automatic gearbox?

I also uploaded a video of mud crossing here to see the level of water:

kusman

bump?

cpnwrench

Ummmmmm.....thats why the external cases and such have seals and gaskets.....

to keep the lube stuff in and the mud and grime and crap out.

so if your seals are good, you should not have to do anything....?


I have had ol red in some yucky stuff and no leaky and no worries just hose 'er off.

just my two cents sir!

cpnwrench

freegdr

x2^^^^^^

Jim_K

Iv also read you have to change your diff oils after a warter passing. I'v done it once and there was nothing in mine at all. All clean good oil.

djb383

If oil/fluid doesn't leak out, wouldn't think water would leak in BUT, oil/fluid never reaches the vent tubes, can that be said about water when driving thru a high water crossing? A small amount of water over time ruins bearings/internals.

Dan91

Ok, assuming your seals were all in perfect working condition it shouldn't be a problem. However, the differentials/other mechanical components are quite hot in comparison to the water. So when it hits the water and cools down, the oil contracts and causes a low pressure zone. The vent tube should allow for air to flow in and equalize pressure, but if the vent is plugged or partially blocked the seals could suck water in. More commonly though I would guess that water just seeps in through old degraded seals. I used to be worried about water etc, but in my experience, as long as you aren't stuck in it or in water for a long time it's fine.

djb383

How about this for a concrete answer........the ONLY time u can be certain there's no water in the oil/fluid, is the time between oil/fluid changes and the next trip into high water.

kusman

Thanks for the answers. The UserCP didn't show any replies to the thread. Just noticed them. Sorry about that.

The seals are ok because they have been recently replaced, the reason I am asking is because these systems are not sealed. Water is sucked through breather holes on the diffs and I know that components will get ruined over time if water is in there.

I have gone to a shop a few days ago an the mechanic said that for an XJ the diff and T-case oil needs changing after getting in the water this deep (basically when diffs are submerged). The auto gearbox should be ok if the seals are good because the breather hole is connected to a hose which is going up an under the hood so water should not get into the gearbox. But unfortunately no 100% guarantee

I hope this helps everyone with auto gearboxes as there is really no info about this specifically.