My front differential
We have a 2013 Nissan Armada that I purchased last year at the end of May. At about 4k miles in the fall sometime, I drained and refilled the front and rear diff with Amsoil Severe Gear 75W-90 to get out all of the break in metal out of the fluid. It has about 14k on the clock now.
-Remove the fill plug to make sure I could get it off before I drain
-Remove the drain plug and empty the old fluid
-Put the drain plug back in
-Fill until it comes out of the fill hole
-Wait for it stop draining from the fill hole and replace the fill plug. Done.
Since then it has driven all over
-December 2013 Indianapolis to Orlando straight, sat for a week, then back from Orlando to Indianapolis straight.
-October 2013 Indianapolis to Mackinaw, MI and back again.
-Multiple trips from Indianapolis to SE Michigan.
-Multiple trips from Indianapolis to Cincinnati (Kings Island) last summer.
This year it has gone to Cincinnati once before as well (it was cooler and the wife was driving it so it most likely a less aggressive trip). The second time was this past Saturday. When we got home, I could smell diff fluid from something. I slid under the mada and saw fluid dripping from the drivers side lower control arm, inside the wheel well looking like it was coming from above from a plastic push pin and multiple other places. So I looked into the engine compartment and under the abs distribution block was all wet as was the space between it and the airbox.
After doing a little more research, I see that the front diff's vent tube goes up next to the airbox. Now it makes sense how I am seeing fluid where I see it. I am still unsure as to why it would have vented so I took it in to the dealer on Monday.
They looked it over and said they couldn't find anything wrong with it. They checked the fluid level and said it was full and they didn't add anything. They said it was probably overfilled from the factory and with it being a hot day, it must have expanded as it heated in to the vent. Knowing I did the last fill, I just took it back since they just inspected it, said it was fine and documented me taking it in.
Now, I am looking for someone to tell me why - how this happened? How could it go almost 10k miles since I changed it and all of the sudden it vents? How could there be too much with my fill procedure. As I recall, when I opened up the fill plug, a little bit of the old fluid started coming out (a couple drips). So when I refilled it, it would have been the same level.
Could the extra volume be water - condensation from the hard winter adding volume and it not burning it off before it got hot and expanded? Is the Amsoil adding volume as it shears?
I've got 8 quarts of Valvoline SynPower 75W-90 on the shelf. Should I dump the Amsoil from both diff's and replace it with the Valvoline?
I'd love to hear your opinion on how my front diff magically added volume to the front diff and needed to vent it.
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