Does anyone know the difference between the 4x4 auto switch and the 4x4 switch and which one is better?

 

From what I gather the auto 4x4 is 2wd until the rear wheels start to slip, then it activates the 4x4. However, there is a slight delay in this switch I believe while the 4x4 switch is always in 4wd.

I also believe that the transfer cases are different and the auto 4x4 t-case uses the auto-trac fluid instead of regular ATF.

 

I remember reading about it in the owners manual but can't remember exactly. It's in there though if you still have it. If not I can go check it out.

 

Yup, 4 auto is 2wd until the rear wheels slip, then transfer case engages the front wheels. It is pretty fast & what I usually use in winter after a storm etc unless I want to play around & drift corners then I leave it in 2wd lol. But the 4 auto is pretty good - you get the benifit of mileage because of 2wd but when it slips you have 4wd (3wd actually if you have the G80 option for a rear posi, front is an open diff). I'm not sure how long after it engages that it releases the front diff, but it isn't a long time/distance.

BTW it always helps to let people know what year, make & options you have as a ride.

 

I thought 4 Auto split the power like 25% front and 75% rear until it slipped then it went to 50% 50%. Or is that only the Bravada?

 

How would it do that unless you're in mud or on ice? That would destroy the front diff.

 

A viscous coupling transfers torque like that, doesn't it? I might be wrong, but I think a lot of AWD (not 4WD) vehicles use a torque bias, like 70% rear, 30% front. And they can transfer torque front to rear as needed by conditions.

The actual gear ratios would have to be the same, I assume, or it would indeed tear up the diffs. But the torque amount is what changes.

 

Sorry. This is my first post. I've been reading for a while bu never posted. I have an 01 blazer 4x4 blue. I'm trying to buy a blue ZR2 blazer for the frame.

 

No, the TC constantly slips... Thats how the Bravada works.. if i can find the thread ill link it. I believe someone said thats how the Auto 4 worked on the blazers also.