low tranny fluid question

[Tbruz]

1997 2 door Tahoe 4WD with 130K miles.
Just checking fluids over this weekend and noticed that my transmission fluid was low, and by low I mean not reading on dip stick at all.
I did have it changed in 2012 at around 100K miles and went with the Amsoil Synthetic ATF. I will be adding more as I get some and truck will not be driven until I get more fluid in.
Questions:
Where did it go?
Under carriage is dry with no sign of leaks. Radiator is still full.

Did I do any damage?
Truck seemed to take a half second longer that normal when selecting reverse at first start in the AM but I initially chalked that up to the super low temps here in the North East. Other than that the truck wasn't acting any differently when driving.
Thanks
Tbruz

 

[Calderone]

The main question is where did it go, check your radiator and reservoir for signs
of fluid on the water, it has to be somewhere.
Do not drive it until you find out.

 

[SunlitComet]

is your t-case over filled by any chance?

 

[Tbruz]

Well it took two + quarts and now i'm back to normal operating level.
Radiator is ruled out as are leaks or trans cooler.
Will pull plug on transfer case later this week to see if 2+ extra quarts spill out.
I'll be monitoring the tranny fluid level every other day or so to ensure level isn't changing.
More to come.
Tbruz

 

[Tbruz]

So the missing Tranny fluid has been located......

Its in the transfer case.
Local Trans shop says the issue is well known with the OBS and that the transfer case needs to be removed and three seals replaced.
Estimate is $400 to $450 out the door
Does this sound reasonable?
Temp here is 20 degrees and I'm getting to old/cranky(my joints not my personality) to try this myself.
Thanks
Tbruz

 

[SunlitComet]

Standard labor to remove the drive shaft and t-case is 3.7 hrs total so that does not sound bad.

 

[Tbruz]

Done for $400 from my local tranny shop.
3 seals replaced(I provided the 2+ quarts of Amsoil synthetic fluid).
They also replaced a rear u-joint since the drive shaft was down already.

Now on to the next project; Tru trac for the rear end to overcome the New England winter.
Tbruz

 

[newbie78]

Yikes 2+ quarts of trans fluid low and how long have you driven it like that?

 

[Tbruz]

Was probably low for about a month before I happened to randomly check fluid levels. As stated the only effect I noticed was a 1/2 second delay, sometimes, going into reverse when stone cold after sitting all night.
Truck runs and shifts perfectly; hopefully no damage was done that will emerge later.
Tbruz