aris_unlimited

I went off-roading the other day in our 07 tahoe 4x4. Still a bit snowy where I was maybe 2 inches of snow in the deep places. And somewhat muddy underneath. Well I got to a turn around spot and when I was making a multi-point turn I backed into a rut that had been covered up with snow, didn't even know it was there. Had been in 2wd the whole time. So I switched to 4hi and tried pulling out, didn't get anywhere. Back tires spinning the whole time. Tried 4lo and same deal. So i decided to get out and push, while the wife tried to pull the tahoe out. So I'm pushing and I can't help but notice it isn't moving at all. Back tires are spinning freely and getting no traction. So I walk around to the front and notice the front tires aren't spinning at all. 4hi, 4lo, traction control on or off. Didn't make any difference the front tires just weren't pulling worth a darn. When we finally got pulled out, I tested it out some more and it seems like the front tires spin some, but have extremely limited power output. Like maybe 10% power compared to the rear wheels 100%.

So basically I guess my question is, what is going on with this thing? Is something wrong with the 4wd or is it just this crappy from the factory?

Don't know if it matters at all but I do have oversized tires on it as well as a 2 inch lift in the front to level it out.

73shark

Your lift may be fooling the ESC, so it cuts power to the front wheels. Otherwise it's not normal for the fronts not to drive when in 4WD.

aris_unlimited

It's not a complicated lift. Just spacers above the front struts. Could that still be messing with it?

73shark

Definitely if it has Autoride, w/o possibly.

aris_unlimited

I don't believe mine has autoride. Any way you can think of to test this out, or to fix it?

73shark

Check for any DTCs.

Did the 4WD work before the lift?

aris_unlimited

Ok, ended up taking the car down to the dealer just to have them check it out. And found out some interesting info. According to the tech down there the 4wd system in the Tahoe is definitely a bit different from some older school versions. He says that it needs about 15 ft of level terrain driving for the front wheels to lock into 4wd. Considering I was off-roading and had it in 2wd until I needed it in 4wd it never went in. As I never had even terrain when I was pulled out, and when I had sank into that rut it wasn't moving at all so I didn't have the room for the front wheels to lock in anyways. Which would explain why I have noticed the 4wd working but it didn't seem to work there.

So basically I need to turn on the 4wd before I am ever going to need it or before I leave the road because of the way it is designed. We did check out the 4wd while we were there and he confirmed that it is working just fine, when all the specifications are met for it to engage.

73shark

Never noticed mine not engaging w/o 15' of travel. Let us known how that works when you get a chance to check it out.

SWHouston

This is the first time I've herd anything about driving it to get it to engage the 4WD. Usually one must wait, until the light stops blinking before moving. If you're not waiting for that light to stop blinking, you should !

When one doesn't use the 4WD, I can see that it may be sluggish to engage, and I would change it from 2 to 4WD, Lo included several times, to "maybe" get things working again. Be sure to give it time to make the changes as stated above.

Also, it may be helpful to directionally center the front wheels, and put the transmission in Park or Natural while changing drives. This is just a guess, but in case there's any Shellac in the transfer case, that may ease the transfer, getting the torsional load off of the systems. One should also check the Oil level in the Case, and it should be changed periodically like the Transmission Fluid.

When you do make the change to 4WD and try to turn the vehicle, you'll definitely know it's done that, since it will resist turning as you drive it. It should be the same feeling as though you are applying the brakes. What I'm saying there is, that you can tell it's in 4WD without jacking it up, or putting it on a free wheel lift. An open parking lot is a good place to try this. plenty of room to turn, stop, change, etc.

PS: On my Burb, it takes it about 10-15 seconds, to go from 2WD to 4WD-lo.

fishing nut

I have not heard of this before. The system should allow you to switch into 4wheel while on the fly, as long as you are going under 55mph the system should engage. I can tell you the other day my wife had to pull over to tend to our son and she got stuck. She shifted into 4hi and it engaged right away, no 15ft of travel needed. This is on a 2011 Suburban 2500, but I would imagine the sytems are similar. I would take it to another dealer.