Rear diff breather vent temp fix?

702_SR5

Member
I just found out that a road I'm planning to drive tomorrow may have a deep water crossing. Reportedly up to 18" deep.

That of course is about the height of the OEM rear diff vent. I have not modded it, because such deep water is extremely rare here in the SW deserts.

I don't have time to do the mod properly today, assuming I could even get the parts together that quickly.

So, if I get out there and the water is deep enough to threaten my rear diff, is there a temporary fix I can apply? Such as using tape or stretch (shrink) wrap to cover the vent? Something I could apply immediately before the crossing, then remove immediately after.

I have one of those small stretch wrap rollers used for moving. Seems like I could wrap the whole thing up pretty well with that. And then just slice it off to quickly remove it.

Thoughts? Suggestions? :shrug:
 
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The diff might be pretty warm, I'll have driven a ways by the time I reach this crossing.

I was planning to change the rear diff oil soon anyway, I've already got the oil and crush rings for the plugs. But I'm not sure I want to drive a couple hundred miles with any water in there!
 
I dunked mine into the Little River after an hour plus drive, and that water runs cold which because science makes the problem worse.

No problems, and the water line was easily at or above the bottoms edge of the door. I’ll change the front and rear fluid every year, and I’m confident it’ll be fine.

I’m considering the ARB breather for peace of mind, but the stock setup works.
 
The rear differential vent is a one-way valve that lets heated air out of the diff housing, and does not let air in. When the diff cools, as when you are not driving it, there is a slight vacuum in the housing. As the theory goes, if you have a really hot diff and suddenly cool it in very cold water which immerses much of the diff housing, the vacuum will increase and suck water through gaskets and into the differential. Or if your one-way valve is gummed up and has failed open you can suck water in that way. That’s the theory anyway.
I wouldn’t stress about it for one water crossing. If you’re worried after the fact, just change the fluid when you get back home. It’s a real easy operation.
 
I went through a stream once before adding the scuba mod with no problems with the diff oil.

One trip temporary fix -- get a piece of tubing to go over the vent, run it up higher and strap it to something. Change diff oil after just to be safe.
 

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Here in Az we go through summer monsoon yearly. And every year I cross deep water on the road and never had 1 issue with the diff.
 
Thanks for the replies.

FYI, below is a pic of what I found at the infamous Meadow Valley Wash crossing.

I've been there before, when the pond wasn't as wide (and not as nasty). That time I waded out and turned around after I reached knee-deep water. So it's safe to assume it's even deeper now. But I wasn't about to wade out this time to check! It was on to Plan B. :heh:

49988899923_39e09515cc_o.jpg
 

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