oil from front diff

[RockinExplorer]

On trip from NJ to NC noticed oil splattered all over the passenger side cv boot,and in the tire well. opon further inspection found a couple of puddles under the hood in the vicinity of the front diff vent tube which has a white plastic vent on it, i looked at the oil and knew it was diff oil, it was dark and somewhat thick, what could be causing this because it never happened before on any trip.

 

[glfredrick]

Your front diff evidently got hot enough to blow out some oil.

I'd do a couple of things right away...

1. I'd drain the oil and replace it with new. Have you gone through any puddles or other water crossings without raising the vent? If so, you have very likely filled the diff with water! A hot diff in a water hole will literally suck in water the same way we suck up a milkshake on a hot day. As the hot diff contracts from contact with the water, it will draw in water through the vent.

2. Raise your vent to inside the hood, near the brake master cylinder area with a long hose.

3. Check to make sure you did not blow the seals. This will be evident by oil in the area of the front C's where the axle joints go into the back of the hubs.

4. Run synthetic oil (Amsoil is my preferred choice) in the diffs. It runs much cooler than regular oils and can handle the extremes in temprature, from hot to cold.

 

[RockinExplorer]

the oil is new just done a couple of weeks ago, and vent is up near the air intake far above where any water could be sucked in, and i haven't gone through any water since getting it changed, and no oil anywhere except from where it came out of the vent

 

[glfredrick]

It is getting hot for some reason... If the stuff I suggested is not your problem, it is probably time to dig in to find out the condition of the bearings, gears, etc. That is WAY to hot for the use you are describing.

 

[RockinExplorer]

upon further inspection the vent tube that the oil is coming from is not the one for the pumpkin but is on the passenger side, which looks like it is for the vacuum disconnect

 

[glfredrick]

That would be worse -- it means that you have a lot of oil in your vacuum stream where it ought not be. Typically, it means that you either have a lot of blow by from bad rings and/or valve seals or that you have a plugged EGR valve that is not evacuating the engine of excess oil vapors.

 

[RockinExplorer]

would a plugged egr set off the check engine light after a few miles of driving

 

[glfredrick]

Perhaps...

You need to hook up an engine scanner (not just a code reader) to see what is going on inside your engine and computer system.

Find someone with either a STAR or a Snap On Solus or Modis to hook into your system. They will give real-time data streams and show exactly what is happening to trip the CEL versus just a code that may or may not be the actual problem (i.e., one of the most common codes is for an o2 sensor, but the sensor is rarely bad -- just sending the CPU a signal that it doesn't like).