Why do my wheels spin when turning into my driveway?

[s4tress]

I just picked up a 2015 S4 2 weeks ago. Love it so far, but there are still some things I need to learn about it.

This is one that is perplexing me...

I have a short driveway, but the angle of the tip of it is somewhat steep for a few feet, before it flattens out. On my old car, I sometimes used to scrape the bottom if I pulled in or out straight on. My prior car was a Honda Accord, and I used to pull in on an a sharp angle which seemed to prevent the bottom from scraping.

Needless to say, I definitely don't want to scrape the bottom of my S4, so I'm experimenting with different ways of pulling in. For some reason, when I do a sharp angle turn into the driveway, I find my wheels start spinning and the only way to get up the driveway is with the momentum of the car itself.

I haven't had someone look from the outside yet, but what I suspect is happening is that when I turn right, into the driveway, the front left wheel is off the ground for a moment. I don't understand though why the car could get stuck in this position, especially since it's AWD. I believe my car has the sport differential. Could that have anything to do with it? Last night I actually had to pull all the way back out and make a second attempt in to get up the incline.

It's a MT, if that makes any difference...

Thanks for any help..

W

[Vogz]

Is there any snow or ice on your driveway? What tires are on the car? Do you have any pictures of it so we can get a better idea what is going on?

[s4tress]

There's no snow. The tires are Dunlop All Weather performance tires, and pretty new. I don't know the exact tire off hand. I'll try to take some pics tonight.

[Johnnycash]

pics would help.

[DGVR6]

3 wheeling when youre pulling in on an angle (1 wheel off ground). It's worst when you have Coilovers too.

That's why

[DGVR6]

It sucks, it spins, once you get traction... Snap. 6mt it takes a bit of finesse to overcome those angle pull in/out

[phanker]

Interesting. The only way for this to make sense is that the S4 is mostly FWD at slow speed. With no LSD at the front, it'll just spin the airborn left wheel.

[DGVR6]

It's usually the rear wheel that lifts off the ground

[bknewtype]

happens to me almost all the time when I go up at an angle

[s4tress]

Thanks everyone. I'll have to read more about this I guess...looks like it's a known/common "issue". I had thought since it is AWD this could not be possible. I still don't completely understand what's going on. I will have to experiment with pulling in a bit more straight on, but then I run the risk of scraping the bottom of the front bumper.

[SteveYem]

I have a similar driveway situation and it happens to me when I turn in from the right side but not from the left. I am lowered on coilovers and have a bunch of chassis stiffening aftermarket parts installed (drivetrain stabilizer, front strut brace, front and rear swaybars), and my guess is that the steep transition, steering angle and chassis stiffness is resulting in one tire losing adequate traction with the pavement.

[superswiss]

Yep happens on these cars. Both front and rear diffs are open and it takes EDL a moment to realize it needs to slow down the airborne wheel to get the car moving. With the sport diff it's better if one of the rear wheels is airborne, but EDL still needs to engage.


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[Ze_Nardo6]

Same thing happens to me when I pull into my driveway at an angle to avoid scraping. It's just the slope mixed with the angle, I wouldn't sweat it.

[MrFunk]

You may also want to look at curb ramps - they are great!


http://www.bridjit.com/

[Bludool]

Gets worse with sway bar upgrades. Chassis is stiff.

[torinalth]

odd. I have a really steep drive and have no yet run into this, also a 6mt with sport diff and sways.

[anerbe]

From what I understand, the front is an open differential and the center (front/rear split) is a torsen diff being 6MT.

Torsen can only transfer power from front to rear if the slipping wheel/axle has some load on it. For your instance, if one front gets up in the air, the other front wheel will not gain any power, as it's an open diff. The torsen will not transfer any power to the rear because the torsen acts a a torque multiplier, of the low traction wheel. Whatever torque it senses on the low traction side, it transfers to the other side. If torque is zero (in the air), there's no transfer.

Two ways to solve it is 1. Stab the brakes while accelerating to brake the spinning wheel in the air, causing torque and allowing the system to tranfer power to the rear, or 2. keep traction control on, which should brake the wheel in the air individually, sending power to the rear. If neither works, you need to simply carry momentum.

[anerbe]

Also, from what I remember, the crown diff (used only in DSG 8.5 S4's), can send power to the traction side, even if one side has zero traction.

[superswiss]

Also, from what I remember, the crown diff (used only in DSG 8.5 S4's), can send power to the traction side, even if one side has zero traction.

Yes, that's correct. The crown diff is self locking and can transfer torque to either axle without traction control needing to brake individual wheels. My B7 S4 (torsen center diff) struggled mightily with situations like this. If I stopped with one wheel in the air it was quite embarrassing to get moving again. The drivetrain made all kinds of noises as traction control tried to reign in the spinning wheel(s) to get the car up the incline. The RS5 with the crown gear handles this much better. There's still some minor wheel slippage, but the center diff pretty much immediately locks and directs the majority of the torque to the axle with traction.