Milk shake diff fluid?

I replaced all my fluids today and was greeted by a milky brown discharge coming from my rear diff.[/IMG] Thinking some water got in thru the breather. Ideas? All the good looking diff fluid in the pan is from the front diff and transfer case. Guess it might be time to do the breather mod.

 

H2O

 

I drove mine right before changing the rear diff fluid and it was not aerated like that. Im betting it's water.

 

Agreed with above....it's water. Check your axel seals and the previous mentioned diff breather.

 

I was thinking axel seals also. Both drums are dry and the pinion seal area. If water can go in, wouldn't gear fluid be coming out?

 

How? This is what I understood and discovered...

The stock breather is a spring loaded, one way (out only) check valve... releases hot expanding gasses only if they build up pressure greated than the force of the spring. The breather is shut closed to the outside, other wise.

The reason we do the rear breather mod. is to put a true (2 way) breather on the diff., but up high, like it is on the front diff.

This way, during negative diff. pressure (caused when driving into a stream or puddle deeper than a foot) water won't suck into the diff. past the axle seals.
This makes the breather dual purpose:
1) Allow expanding gasses out.
2) Break the vacuum with fresh air to prevent the siphoning-in of dirty water.

 

It doesn't matter.... It's NOT a completely sealed system & can't be.

If you've ever looked at one of those breathers...it's a cheap monkey metal looking cap ontop of a plastic thing-a-ma-bob which appears to have springing motion. It only really protects from overspray/rain.

By the looks of your avatar...you go offroad with your truck. If you sink your diff in water/mud, you're gonna get water inside that breather.

Everyone who takes their trucks offroad - needs to extend their diff breathers! Cheap & easy insurance to protect your diffs!

 

When a HOT differential is driven into COOL water...

The stock breather is really a VENT, that takes some pressure to open the spring loaded check valve... The stock breather does NOT allow anything to get INTO the diff.

So, the muddy water MUST get into it via another place... and that other place would be the axle and driveshaft seals.

By using the same breather that Toyota uses on the FRONT, for the REAR (with this mod), we provide a 2 WAY breather, up high... so hot gasses can escape (as before), but also no vacuum can be created to suck water past the axle seals either... since this true breather will let air rush in during the event.

 

X2 I did a valve cover filter for my breather in the engine bay No no vacuum can be created in my setup.

It way like 6 bucks on Ebay

 

I am not nuts (on this anyway).

The rubber disc sits on the opening, and the spring pushes down against it. You can blow air out of the diff side with some force to open the valve... as in hot gasses escaping the diff..

However, unless that spring and rubber disc is removed, you cannot blow air into the diff. Blow as hard as you like! The water is NOT getting in here with that disc and spring in place. It gets in past the axle seals.

Putting a 2 way breather in place of this one way one in your picture (up higher at the end of a hose), is what eliminates a vacuum that would cause water to get it. Why does Toyota do this on the front diff., if not true? (of course, why don't they do it on the rear??!!)

 

who cares how the water gets in there, all that matters is we all know the fix

 

Water is not getting in through the factory breather... Relocating is only a waste if you put the same one way breather on the end of the tube... You must use the same breather that Toyota uses on the front (or a filter)... to allow 2 way air movement.

The purpose of the different breather, re-located, is to break the vacuum so water doesn't suck into the diff. past the axle seals.