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5EAT - is it still AWD in Reverse?


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[quote name='mlloydlgt']OK.. no towing... but is it a 2wd/fwd when the ignition is off?[/QUOTE] to reiterate the already posted correct answer [quote name='Ken S']5EAT uses a planetary differential to split torque 45:55. Then, there's an electronic clutch pack that helps move torque from that set point. 5EAT in reverse should also be powering all four wheels. The 4EAT automatics use only a clutch pack to transfer power. Ken[/QUOTE] so no. REad you r owner's manual 4eat cna be towed limited distances if you disconnect a fuse. the GT in both AT and MT trim are AWD all the time.
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[quote name='mwiener2']quatro is a symetrical awd system?[/QUOTE] I don't believe Audi's system is symmetrical. Audi doesn't employ the low center of gravity or the straight through drive-line that Subaru does. Most Audi models don't have drive-lines that go stright into the transmission. Most take a detour to match up to the transmission on the left. That wouldn't be symmetrical.
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[quote name='mlloydlgt']Back to Subarus..... Does the 5EAT then only act as AWD when it is on and electricity is being sent to the locking mechanism? Meaning that it would be able to be towed on 2 wheels if power is removed? Mike[/quote] I'm a bit curious about this also. I recently had all 4 wheel off the ground and found the following (XT with 5EAT). While in Park, if you try to turn a front wheel, the other front rotates in the opposite direction. If you block one front wheel, you can't turn the other front. If you turn a rear wheel, the opposite wheel rotates in the same direction (due to the LSD rear diff) but at a slightly slower rate. What this means is that the driveshaft is turning. Turning the ignition on seems to make no difference in this behavior. I guess you'd have to develop a greater speed differential between the front and rear axles than what I could turning them by hand to get the system to engage. It also means the rear wheels won't help any with holding the car in place when in Park.
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[quote name='Cynder']I don't believe Audi's system is symmetrical. Audi doesn't employ the low center of gravity or the straight through drive-line that Subaru does. Most Audi models don't have drive-lines that go stright into the transmission. Most take a detour to match up to the transmission on the left. That wouldn't be symmetrical.[/quote] I haven't looked at any of the newer models to be able to say, but the older Quattros (4000, 5000) were definately symmetrical.
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OBieXT- I witnessed a similar thing on my 5MT. It was actually fairly disheartening. I was getting an allignment done and the tech was having some problems figuring out that my car was awd. He would set up one wheel, then go to the next wheel and spin it to line up the machine. But the wheel he had just set now moved and so on. Basicly, moving any one wheel, made two others move.

(Updated 8/22/17)

2005 Outback FMT

Running on Electrons

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[quote name='mwiener2']OBieXT- I witnessed a similar thing on my 5MT. It was actually fairly disheartening. I was getting an allignment done and the tech was having some problems figuring out that my car was awd. He would set up one wheel, then go to the next wheel and spin it to line up the machine. But the wheel he had just set now moved and so on. Basicly, moving any one wheel, made two others move.[/quote] That pretty much what I would expect to happen on an AWD. If you turn one wheel then something else should have to turn. Assuming you have the trans in Park (or any gear with a MT) if you turn a front wheel, the other front should rotate the opposite direction, or the driveshaft should turn because of the center differential. Likewise with the rear. If you turn a rear wheel the other rear should turn in the opposite direction, or (because of the LSD) if both rears rotate the same direction it forces the driveshaft to turn. Turning the driveshaft should force the fronts to rotate. With the 5EAT however, the driveshaft turns (with some drag but not a lot) without either of the front wheels turning. Its like there's a tremendous of slippage in the center diff or the rear driveshaft is just not engaged. Anyone know how this VTD system works?
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[quote name='Cynder']I don't believe Audi's system is symmetrical. Audi doesn't employ the low center of gravity or the straight through drive-line that Subaru does. Most Audi models don't have drive-lines that go stright into the transmission. Most take a detour to match up to the transmission on the left. That wouldn't be symmetrical.[/quote] With the exception of the the TT, A3, and the A4 Cabriolet, all other Audi products (A4, S4, A6, S6, A8, A8L, S8 for the U.S. Market) are symmetrical with a longitudinal engine layout coupled directly to a front transaxle (just like Subaru), followed by a rear drive shaft out of the back of the transaxle (just like Subaru) coupled to a rear differential/axle (just like Subaru). The difference is, as I indicated in a previous post, in the execution where Audi now uses open diffs and controls spin by braking (using the ABS) to controll spin at each end of the axle. Hard on brake pads for sure.
- Pro amore Dei et patriam et populum -
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[quote name='Subietonic'] The difference is, as I indicated in a previous post, in the execution where Audi now uses open diffs and controls spin by braking (using the ABS) to controll spin at each end of the axle. Hard on brake pads for sure.[/QUOTE] Hard on the disk pads but probably easier to integrate the stability control this way. I read that one of the main problems with AWD is the integration with the Stability Control. The AWD basically has to "disengage" while the ABS did its work to get the car inline. If it didnt disengage the two systems would step on each other for control in slippery conditions. One of the reasons why the VDC on the outback is so sophisticated and expensive because the computers and mechanics have to work together for the VDC to work well.
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  • 2 months later...
[quote name='c_hunter']2.5i -- 5MT gets the viscous coupling 50/50 "continuous AWD", while 4EAT gets "Active AWD" with the clutch pack GT/XT -- 5MT gets continuous AWD and adds a limited slip rear diff, 5EAT gets the VTD AWD system[/quote] i just searched and found this thread for something else, but ive gotta clear this up. ALL 5mt outbacks, (xt or not) have a rear LSD; something something model differentiation?
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[quote name='mwiener2']ALL 5MT Leggey or outback, 2.5i or 2.5T ALL have rear LSD and the thread is back from the dead....again[/quote] Sorry MW2 - In NA variant only the NA Outbacks get the rear LSD but NA Legacys do not. So your statement should read: NA 5MT and AT (4EAT and 5EAT) Outbacks (including the 2.5, 2.5Ts and 3.0s) all have rear LSD FI 5MT and 5EAT Leggys have rear LSD. SBT
- Pro amore Dei et patriam et populum -
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