06 Tundra Transfer Case, Amsoil SVG 75W-90, 14,939

[btanchors]

I'm happy with this report...Iron is now down to a reasonable level. All I did was I installed a magnetic drain plug at the beginning of this UOA. The old drain plug was NOT magnetic.

The next step is to tackle the high silicon. I know it's not an additive from the Gear Lube - A VOA as well as many UOAs I have performed on other units using the same lube don't show anywhere near this level of Silicon. I doubt it is from sealers, as I would think by now the Silicon level would have significantly declined by now. I am wondering if there is a breathing tube or some vent that dirt is getting into. I will examine the shop manual and see; I haven't noticed one while servicing this unit, but I am not sure what to look for either. Comments?

 

[INDYMAC]

Thanks for posting btanchors. I have a 2000 Tundra, but haven't tested the t-case oil yet. It looks like things are trending downwards though.

I wonder why the flashpoint dropped so much?

I wonder if the seals have a silicon componenet?

How much/often do you use 4X4?

The breathers for the front diff and t-case are located side by side on the drivers side wheel well. You can see tham when you open the hood. How do I know? Because they splatter gear oil everywhere when these units are over-serviced!

 

[unDummy]

Fe/Cu looking much better.

Was there a recent VOA of the SVG?

Si either sucking in some dirt or part of additive package.

I'd go 30k or 2years on the new fill.

 

[btanchors]

unDummy-

It seems like it was just yesterday, but the VOA I had done is actually almost three years old! Here it is anyway: VOA_Amsoil_SVG

Another one needs to be done as Amsoil recently announced a formulation change to the Severe Gear line of fluids.

 

[unDummy]

Was there any buildup on that new expensive fancy magnetic drain plug?

 

[btanchors]

There was a minor amount. Plus a couple of larger "grains" of metal, about the size of the tip of a pin.

 

[unDummy]

Of the 80k miles on the vehicle, how many are with the 4wd on? that transfer case is probably just broken in now ;-)

Minor amount of wear on magnet along with a couple specks is fine. I'd wager that the gears are powdered metal. If so, they'll shed forever until they disappear, just like a salt lick.

Don't forget that there is still an internal xfer case magnet. When the fluid is draining, there might be some 'magnet wash' of the internal magnet. Could be the cause of the excessive Fe in earlier UOAs. With the magnet drain plug, less on internal magnet leads to less washing into your UOA sample bottle.

 

[btanchors]

unDummy, of the 80K, I would guess that perhaps 1K has been spent in 4WD - in other words, not very much.

I've been told that the transfer case operates 100% of the time, even when 4WD is not engaged. I do not know whether this is correct or not.

 

[unDummy]

Of course there is power transferred through the transfer case, otherwise your 2wd wouldn't work. But, there isn't any traveling up through it(sideways) to the front prop shaft. So, your power is going in a straight line through it.

In 2wd, power goes from the input to rear output shaft.

In 4wd Hi, you engage the gear:chain:gear to add power to the front output shaft. If you've ever pedaled a bicycle with a loose back tire axle, you'll know how much twist is working on the "rear output shaft+gears+chain+transfer case housing+front output shaft".

In 4wd Lo, you engage the planetary in between the input and output shafts. Basically your input shafts spins twice as fast as your outputs meaning you crawl. More components engaged adds more wear.

The transfer is always working but NOT all of it is always wearing. You select the wear points by using the 2wd, 4wdHI, and 4wdLO.