OEM Breathers water resistance

I've been curious about the OEM breathers on the transmission and transfer case. I know the diff breathers are up by the battery and well above most other components, but the breather from the transfer case and transmission (according to a couple of other postings) are much lower and behind the engine. I'm just curious, do those breathers prevent water intrusion by closing a valve or are they just there to equalize pressure? I'm asking because I've driven in some deep water and I got my truck in some water deep enough to get a little water in the cab. I had a couple of repairs but everything seems fine, but from reading, I wouldn't notice water intrusion in the transmission or transfer case until it's too late for either of those parts. I plan on flushing my transfer case but I've been warned against flushing my transmission as I am over 130k miles and I don't know the history of the truck before 70k miles. thanks in advance for any information.

 

Run the truck. Get the transmission hot enough and the water will burn off (evaporate). Do you have a rear diff breather relocate?

 

I got looking at the truck and the breathers look like they may have just barely been above the water line, so I think I have minimal intrusion, no I haven't done the rear diff breather mod but I did flush that as soon as I got the truck back home. no issues on the LSD that I've noticed.

 

In theory, the diff breather will not let water in. When working properly, it’s an exit vent only. A hot diff could allow water in, if it was venting and plunged into cold water quick enough.

When those breather vents get old, the seals crack and they no longer seal properly.

ARB makes a good kit for breather relocation.

 

Do the rear diff arb kit…it’s super easy install, and good peace of mind. I placed the vent behind my rear taillight. The fronts sit high and are gtg.

 

May I ask what the transmission flush warning was and why? Many of us, including me, won't get prior service histories.

 

It’s a bit of fear mongering. The story is the only thing keeping a worn transmission running is the grit in the transmission fluid. The transmission “clutch packs” has to really on its last legs for this to be a fact. Professional mechanics don’t want to deal with customers complaining about slipping transmissions. Kind of like the don’t use synthetic oil because it causes …..

 

I've been told that getting a transmission flushed near, at, or after 100k miles has the potential to knock loose any metal bits that have been shaved off and could cause more damage. I have also been told that a fluid change would be fine but using a machine to fully flush the transmission would be a bad idea. I don't know if there's any stock in that, but I'd rather be safe than out 4 grand for a new tranny

 

Do a drain and fill.
Then do it in another 20k

 

I'll probably end up doing that in the next week. My rear diff didn't have any water in it and neither did the transfer case even though the transfer actuator was filled to the brim with water. I'm not super worried about it and it seems like it's running fine. but, like I said, safe than sorry.

 

yes that is the key point, peace of mind is worth the time and the $90 or so for the ARB filter relocation

 

ARB relocation is already on the way lmao

 

Thanks good info.