4wd Locks?

[smorse52]

I am an EXTREME beginner in the world of 4x4. I have an 07 Z71 Tahoe, it has been tuned and I will hopefully soon be lifting and putting some tires on her. I noticed I had some rubbing noises in the driver side front and just got it out of the shop it had 36k on it. It was the hub bearings. When I was out at an atv park last weekend I noticed when I cut the wheel in 4wd and turned it was humming. Now it doesn't. So I am assuming it was linked to the bearings. However I did notice that it does seem that the limited slip goes away when in 4 x 4 mode. If you cut the wheel in 2wd my truck seems to advance. If you cut the wheel in 4wd it doesn't move at all and I notice the wheels seem to howl as if the tires are locked. I didn't think it locked but it seems it does. Any background? And if it locks is it affected by the electronic controls? Should I turn off the traction control etc. when offroad? Hopefully not too many questions, but it's the only way I can learn. Thanks

 

[stevek]

I am an EXTREME beginner in the world of 4x4. I have an 07 Z71 Tahoe, it has been tuned and I will hopefully soon be lifting and putting some tires on her. I noticed I had some rubbing noises in the driver side front and just got it out of the shop it had 36k on it. It was the hub bearings. When I was out at an atv park last weekend I noticed when I cut the wheel in 4wd and turned it was humming. Now it doesn't. So I am assuming it was linked to the bearings. However I did notice that it does seem that the limited slip goes away when in 4 x 4 mode. If you cut the wheel in 2wd my truck seems to advance. If you cut the wheel in 4wd it doesn't move at all and I notice the wheels seem to howl as if the tires are locked. I didn't think it locked but it seems it does. Any background? And if it locks is it affected by the electronic controls? Should I turn off the traction control etc. when offroad? Hopefully not too many questions, but it's the only way I can learn. Thanks

Read this
http://en.wikipedia.org/wiki/Four-wheel_drive#Off-road_drive

 

[Zed 71]

If you cut the wheel in 2wd my truck seems to advance. If you cut the wheel in 4wd it doesn't move at all and I notice the wheels seem to howl as if the tires are locked. I didn't think it locked but it seems it does.

Sounds like you did this on the road and was it in Auto or 4HI? Do not engage 4 mode on the road because you will definitely break the drivetrain.

You may have a rear locker. Look in the glove box and see if G80 is listed. If so you have the Eaton automatic locking differential.

Since you are new to offroading, just take it easy and leave traction/stability on. More clearance is a must and we can help over in the lifted section. Make sure you list your goals, offroad use, and budget; that will help with suggestions.

Good luck.

 

[smorse52]

4wd Locks

Thanks for the input. I pretty much have the grasp of the operation and function, but not the inner mechanics. We were out watching some rock crawlers, etc. last weekend and I kept hearing about lockers. So I was curious as to the stock setup of Tahoe's. Again I appreciate the feedback. The info on this site is invaluable. I had an issue in my tahoe and the mechanics kept saying I was imagining things. I came to the site, typed my problem and saw a pinpoint response. Brought it to the dealer asked them to check it, they said if it's not the problem we will charge a hundred bucks for diagnostics. I said, do it. I wasn't Hallucinating, the problem was there. So I value all of the opinions I get from this site.