Front diff pressure inside

[katit]

Just a quick Q for all on why it might be. When I was replacing oil, plug was removed and I heard distinctive sound. Whole diff was under pressure inside. It wasn't hot either.
I know there should be a breather for it, right? How does it work? Should there be pressure? I assume answer is no..

 

[AZMoonshadow]

You are correct, there shouldn't be excess air pressure inside the differential. The vent tube and breather valve is designed to let out the air pressure. I would check your rubber tube and the check valve (it's a one-way valve). If the problem isn't fixed (and it may have already happened) the pinion seal or axle seals will get damaged and start to leak fluid. Unfortunately, the check valves are a poor design. It's supposed to let out air pressure and not let water in. It doesn't always work that way. If water mixes with the gear lube, you can have more problems. I've replaced mine with OEM valves and then gave up on them in favor of this:

 

[katit]

Ok, it's good to know it's somewhat known issue. Truck is not water-crossing machine, as long as it vents - I will be OK

 

[Notracks5150]

Just a quick Q for all on why it might be. When I was replacing oil, plug was removed and I heard distinctive sound. Whole diff was under pressure inside. It wasn't hot either.
I know there should be a breather for it, right? How does it work? Should there be pressure? I assume answer is no..

The answer is no.
I just left a thread about stopped up breathers, front and rear.
They should pass air freely.
If not you risk blowing out pinion and axle seals. The vent hoses, caps, and even the nipple will crud up over time.

 

[Notracks5150]

Ok, it's good to know it's somewhat known issue. Truck is not water-crossing machine, as long as it vents - I will be OK

 

[Notracks5150]

View attachment 3658637

View attachment 3658638

Front and rear location.

 

[katit]

Will have to look tonight. Just yesterday was working on PS fluid, etc and don't remember seeing breather.

 

[Notracks5150]

Will have to look tonight. Just yesterday was working on PS fluid, etc and don't remember seeing breather.

There's a little plastic clip up front that holds it that might have failed. Causing the end to disappear.

 

[katit]

Answer why I didn't see it simple - there isn't one.
Now main Q. What happened? This car is just.. Not good people were working on it

I understand this is breather hose nipple. There is some red rubber plug in it.
Options:
1. Someone put some kind of rubber/plastic plug in there after destroying breather hose??
2. New diff was installed at some point and they come plugged from factory?
3.?

I need to fix it right now.. But car been driving like this for a while I guess. No leaks from axles.. And I think it was overfilled a little.

Looks like I have this circled nipple plugged and everything else is missing. WTF?

 

[Notracks5150]

Answer why I didn't see it simple - there isn't one.
Now main Q. What happened? This car is just.. Not good people were working on it

I understand this is breather hose nipple. There is some red rubber plug in it.
Options:
1. Someone put some kind of rubber/plastic plug in there after destroying breather hose??
2. New diff was installed at some point and they come plugged from factory?
3.?

I need to fix it right now.. But car been driving like this for a while I guess. No leaks from axles.. And I think it was overfilled a little.

View attachment 3659036


Looks like I have this circled nipple plugged and everything else is missing. WTF?

View attachment 3659040

At least you caught it. I'm guessing option #2

 

[LJE]

Answer why I didn't see it simple - there isn't one.
Now main Q. What happened? This car is just.. Not good people were working on it

I understand this is breather hose nipple. There is some red rubber plug in it.
Options:
1. Someone put some kind of rubber/plastic plug in there after destroying breather hose??
2. New diff was installed at some point and they come plugged from factory?
3.?

I need to fix it right now.. But car been driving like this for a while I guess. No leaks from axles.. And I think it was overfilled a little.

View attachment 3659036


Looks like I have this circled nipple plugged and everything else is missing. WTF?

View attachment 3659040

I'm just glad whoever owned/worked on your vehicle didn't touch mine, wow! That's crazy. I'd rig up something temporary and order the correct parts from Impex or Partsouq myself.

 

[katit]

I'm just glad whoever owned/worked on your vehicle didn't touch mine, wow! That's crazy. I'd rig up something temporary and order the correct parts from Impex or Partsouq myself.

All those parts NA, but of course I grabbed one from eBay. Some cleaning and it should work. Will be here tomorrow.. Might replace piece of rubber hose.

 

[Land Shark]

1/4" fuel line plus clamps picked up from any LPS and you are in business...