Anyone?
Autotrac???
So i have a 2002 Chevy Suburban with the Auto-Trac transfer case. Just wondering how the Auto feature works because when engaged the fronts do pull but i can still spin the rear tires pretty good. For Example when the front is on cement and the rear on sand In Auto mode the front pulls but the rear is still allowed to spin.
I was told In auto Mode it works Pretty much like An all wheel drive. It can send very little or alot of power to the front tires depending on how bad the traction situation is. And i was told this is possible because of the operation of the clutches is this true???
Also is there any type of sensors which can sense when the throttle is being applied to fast which engages the clutch packs to send some power to the front tires?
Thanks
Jared.
I was told In auto Mode it works Pretty much like An all wheel drive. It can send very little or alot of power to the front tires depending on how bad the traction situation is. And i was told this is possible because of the operation of the clutches is this true???
Also is there any type of sensors which can sense when the throttle is being applied to fast which engages the clutch packs to send some power to the front tires?
Thanks
Jared.
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I would imagine Auto mode would just run with the clutches disengaged (ie RWD), then if the ABS sensors see the rear wheels spinning much faster than the fronts it will engage front wheel drive. So you should be able to spin the rears a bit then the fronts should bite. I don't have any in-depth experience with this particular system but that is how it should go more or less.
i assume auto is RWD too, until slippage occurs, that is why you are getting the pealing.............haha, then the front kicks in and you have the pulling. I could be speaking out of line, I am not a tech but I play one on tv.
i dont know how it does it, but thats what it does. it lets the back tires spin and then engages the front. when traction is regained the fronts disengage.I would imagine Auto mode would just run with the clutches disengaged (ie RWD), then if the ABS sensors see the rear wheels spinning much faster than the fronts it will engage front wheel drive. So you should be able to spin the rears a bit then the fronts should bite. I don't have any in-depth experience with this particular system but that is how it should go more or less.
What a lot of the AWD systems do is they have this viscous coupling, when one side spins faster than the other side the fluid inside turns thick and "locks" the coupling then you get four wheel drive 
but I think this system is just electro-mechanical.
but I think this system is just electro-mechanical.
Anyone?
Sorry, I usually don't come onto GMI on the weekends anymore...
That being said, all the previous answers are 100% right based on what I've learned.
fixed it for ya!i assume auto is RWD too, until slippage occurs, that is why you are getting the pealing.............haha, then the front kicks in and you have the pulling. I could be speaking out of line, I am not a tech but I did stay at a Holiday Inn Express last night.
hahaha, nice change!!fixed it for ya!
In cases like this, just go ahead an engage 4WD High and lock the system since you know you need it. That's easier on the mechanicals than having the transfer case engage under pressure at a higher RPM. Remember, your driveshaft is spinning at between 3 and 4 times the speed of your tires and that Auto will engage while your tires are spinning, not as the start to spin.
Anyhow, in the case you describe, I'd engage 4WD High and as soon as you're free of the situation or on pavement, return to regular 2WD.
Also, as a tip, I would suggest engaging AUTO once every few weeks for a mile or so to keep your front end operating smoothly. It seems to help. I'll even kick mine into 4WD High while on a straight road for a mile or two if I had not engaged it in a while.
Your owners manual will detail your four wheel drive system and recommened methods of engagements and when to use.
Anyhow, in the case you describe, I'd engage 4WD High and as soon as you're free of the situation or on pavement, return to regular 2WD.
Also, as a tip, I would suggest engaging AUTO once every few weeks for a mile or so to keep your front end operating smoothly. It seems to help. I'll even kick mine into 4WD High while on a straight road for a mile or two if I had not engaged it in a while.
Your owners manual will detail your four wheel drive system and recommened methods of engagements and when to use.
1 - 10 of 10 Posts
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