Question?? Auto 4WD

[oneradride]

Am I missing something or is auto 4x4 the dumbest thing ever? A tire breaks loose and all your sh!t slams in 4wd? That’s got to be good on the suspension & transfer case………

 

[boostaholic]

Not really, my truck does it constantly with the awd. You have to remember with the auto 4x4 the shafts are already spinning so it doesn't create much stress to send power to the front driveshaft. GM wouldn't have gone this route if anything was sketchy.

 

[radkon]

I'm wondering if there is any logic in the BCM that engages 4wd if air temps are below a threshold? Considering anytime its below 30 degrees the truck warns me of ice wouldn't that make sense?

 

[boostaholic]

You drive a chevy, not a german sedan lol.

 

[Yang1815]

leave it on 2WD then... that's why there are buttons for it.

 

[oneradride]

LOL thanks Yang, I knew I would get some well thought out, expert responses.....

that's why there are buttons for it

No shi!t?

 

[667theneighbour]

Not really, my truck does it constantly with the awd. You have to remember with the auto 4x4 the shafts are already spinning so it doesn't create much stress to send power to the front driveshaft. GM wouldn't have gone this route if anything was sketchy.

Since there are no frewheeling hubs the shafts always rotate. I think the AUTO button engages the front diff. I guess some kind of clutch connects the front diff to the transfer power when necessary.

 

[boostaholic]

Yeah it's a shift fork but there isn't any real shock load stressed on the driveline since the power from the tcase is already there. Only real issue with the autotrac is when lifted, I always install a dual cardon cv shaft otherwise it vibrates like hell at highway speeds in 4hi.

 

[boostaholic]

Some good info here, I'll try to find an exploded diagram of the front diff/tcase/axle disconnect
http://www.denalitrucks.com/documents/TL_Jan03.pdf

 

[667theneighbour]

I'm wondering if there is any logic in the BCM that engages 4wd if air temps are below a threshold? Considering anytime its below 30 degrees the truck warns me of ice wouldn't that make sense?

Nope. It can be below freezing without the need for 4wd. I rarely use the 4wd and I drive on ice and snow for several months each winter. I use the AUTO when I'm flying by all the sunday drivers who believe snow and ice means 30mph speed limit and switch over to 2hi when they're lost in the snowcloud behind me.

 

[thaslick1]

so should I drive in 2wd or auto????

 

[667theneighbour]

so should I drive in 2wd or auto????

Use the mode you feel comfortable with. As long as you don't use 4wd on dry, firm surfaces. If you have good winter tires Auto and 4hi is just as a help up steep hills, severe conditions and when overtaking others to keep the rear wheels behind the front wheels.

 

[oneradride]

I used the auto function once, 5 years ago, the day after I bought my truck. I rod the hell out of it, so when the tires started spinning I romped it, started into the power slide then that b!tch kicked in and thought the entire front is was going to come off. The logic built into these trucks might be great but I’ll decide when I want it locked in. Maybe it’s for people who drive normal??
:yesnod:

 

[667theneighbour]

I used the auto function once, 5 years ago, the day after I bought my truck. I rod the hell out of it, so when the tires started spinning I romped it, started into the power slide then that b!tch kicked in and thought the entire front is was going to come off. The logic built into these trucks might be great but I’ll decide when I want it locked in. Maybe it’s for people who drive normal??
:yesnod:

4WD power slides are much cooler!!!

 

[Rollin Thunder]

My auto on the 06 was smooth as silk. bairly felt it. I noticed it as there was a funny feeling through the gas peddle. My 03 silvi. WAM, BANG. But I would actully not like the below freezing thing. It was 24 here yesterday and clear as a day. ANd today its 45 and rainy.

 

[boostaholic]

60 degrees and sunny here, must suck to live in VA

 

[Rollin Thunder]

60 degrees and sunny here, must suck to live in VA

Yea but it was 85 on christmas eve and 78 on christmas day. Were in our winter month. It will not get above 50 except for 1 or two days. IF were gunna get snow january is our month. Once february hits (like the 1st) instant 60-70 with a fluke 50. then march bumps up to 80 then april may, june are about 85 with a 90. July augest are 105-125. LOL

 

[667theneighbour]

You should live here. -20 degrees C is common in the vinter and below -30 dc isn't unusual. Kinda like Alaska I guess.

 

[puckhead]

When you get down to -40 degrees F let me know. Last year or the year before someone recorded -55 degrees F. That was not an official reading but still pretty cold. this year isnt too bad though. Coldest it has been is -15. its 30 today wich is kinda wierd but it will probably snow

 

[Rollin Thunder]

only -15. WTF. our coldest night was two nights ago at 26. That set a record from 1987. :smilielol: I hate cold. 115 degree day, wonderful. take the boat out, go water skiiing, go to the beach and surf, jump in the pool. what ever. LOL