4WD, really?

My 2000 tundra has 4WD emblems, but it's not really four wheel drive because it only drives one rear wheel (discovered in a moment of slush on the roadway. I would like to install posi on the rear only, but wonder if that is acceptable with the toyota system.

 

I dont get it.. are you discovering that the diffs are open?

 

One of the first mods I made to my '02 4WD was to install a Kazuma/TRD LSD, much better traction.

 

So your front differential is not engaging?

 

Shifting into 4wd, the front engages, shift out and only the right rear wheel drives. I would expect both wheels drive if I had LSD, but they don't so I want to install LSD on the rear. I found this out at 60 mph on a mountain road, went to my local dealer and asked if they could honestly label it as 4wd when the left rear doesn't drive as it would if LSD. Which number on the pumkin ID tag indicates whether or not it's LSD?

 

A two wheel drive without Limited slip is still called a two wheel drive, not one wheel drive.

 

Shouldnt really be going 60mph in 4wd either.

 

Gen 1 tundras have tons of options.

Look into lockright systems. Full locker can be installed into your open diff

 

Does the 2000 not have the fake LSD switch? (2019 here; we can press a button and the system will work the brakes to limit slip)

 

No. But they did offer a limited slip option.

 

Gotcha

 

The 02’ came with the LSD as a package. Its a true LSD by Eaton/Kazuma. Cost when new on the sticker was $275.

 

Any 4wd truck with open differentials regardless of make would have had the same thing happen.

 

Okay, I said it before but then I saw a squirrel. I'll write all about first gen diffs tonight.

Here you go.
https://www.tundras.com/threads/whats-in-your-rear-end.42904/

 

To clarify the discussion, my gripe about badging was that two wheel drive does not have a 2WD badge because it's assumed, yet a vehicle specifically badged as 4WD should be just that. The other note was that I was in two wheel drive at 60 mph, when I first discovered my truck (which was new to me) must have an open diff. My usual driver is an Audi S4 quattro, and there is no question about its ability in almost any condition (been known to push snow higher than the front bumper, even with 225/50 all season tires).
I should have been more specific (mea culpa), I am looking to install LSD and that has been answered, so thank you.

 

That's just the way a differential works. When one wheel loses traction, all the power is sent to that one wheel. It's not ideal -- in fact it's the exact opposite of what you'd want to happen.
But to be clear, the 4WD designation refers to the relationship of power distribution between the front and rear axles. In a 4WD vehicle, the front and rear axles are "locked" together. Meaning if the rear axle spins one revolution, the front must also spin one revolution. Your Audi on the other hand is AWD, which means there's some means of "give" between the front and rear axles. I presume it's a viscous coupler, but I'm not sure as I don't follow Audi's technology closely.

Adding limited slip to your Tundra's rear axle should help traction a lot.