Quattro Crawl - Low Speed Shudder - B8.5 A4 vs. S4

[S4LI]

Brought my car in today to have a leaky motor mount replaced under warranty. They gave me a new A4 as a loaner.

My 2013 S4 has always exhibited a pronounced low speed "Quattro Crawl" vibration/diff shudder when cutting the wheel and accelerating at parking lot speeds. Multiple Audi dealers have confirmed that it's normal and it's just the diffs catching up to the change in speeds of the turning wheels. That said, the A4 loaner is also a quattro and no matter how hard I cut the wheel or how I drive it, I get no shake/shudder at all from the center diffs. My friends 2.0T C7 A6 also doesn't do the diff/shudder thing. So is it really an S4 thing or is it on a car by car basis? Anyone go from an A4 to an S4 and notice this pronounced difference?

[kobrian85]

Doesn't the A4 have the Halidex AWD system, same one the 8P A3 has?

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[theedge111]

Doesn't the A4 have the Halidex AWD system, same one the 8P A3 has?

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Nope

[superswiss]

Is your S4 a 6MT? The low speed shudder is an artifact of the older torsen center differential, which is still in use with the manual transmission. The B8.5 automatic transmissions (both tiptronic and S-tronic) use a newer center differential that among other improvements doesn't have this low speed shudder problem anymore. If your S4 has a DSG, then something is wrong with your drivetrain.

[Dubious]

Anyone else confirm the above statement? My B8.5 does this but never thought anything of it.

[DBL R]

My 13 s4 does this also.

[DBL R]

Also this topic has been beat to death. Here is another thread about it.

http://www.audizine.com/forum/showth...low-speed-turn

[S4LI]

Yeah, I've read the older threads and always felt it was "normal" based on that and hadn't thoight about it in years, but then I drove the 2015 A4 today and assuming it has a similar AWD system, there was no quattro shudder at all, no mater how I drove it. Not sure how the S4 drivetrain differs from the A4 in terms of crown center diffs etc. Obviously it has a ton more torque than the A4 which I guess could help explain it. Both cars are on 18s with all-seasons as well.

[superswiss]

Yeah, I've read the older threads and always felt it was "normal" based on that and hadn't thoight about it in years, but then I drove the 2015 A4 today and assuming it has a similar AWD system, there was no quattro shudder at all, no mater how I drove it. Not sure how the S4 drivetrain differs from the A4 in terms of crown center diffs etc. Obviously it has a ton more torque than the A4 which I guess could help explain it. Both cars are on 18s with all-seasons as well.

As I posted above, as of model year 2013 you should only feel this shudder in models with longitudinal manual transmissions. You shouldn't feel this in an S4 with S-tronic or an A4 with tiptronic etc. You can go down to your dealer and test drive anything from an A4 all to way up to an RS7 to see for yourself. I know this shudder very well. I lived with it for ~8 years in my B7 S4 6MT. The 2013+ S6, S7, RS7 and S8 don't do it and they have a lot more torque. The 2013+ S4/S5 with S-tronic doesn't do it nor does the RS5. When I was in the market for my RS5, I test drove a 2013 S5 S-tronic and the young and eager sales guy who actually knew the cars he was selling made a point of taking me to a parking lot and do some full lock circles to demonstrate how this car doesn't have this shudder anymore.

[Dubious]

For me is seems noticeable first few turns out of parking spot. If my memory serves me right, it seems this goes away after first few slow turns after startup. I don't drive much in parking lots and have not tried slow speed full wheel lock turns.

[Dubious]

Also this topic has been beat to death. Here is another thread about it.

http://www.audizine.com/forum/showth...low-speed-turn

Read through thread. Thanks for the link. Ill chalk it up to being normal.

[troyerco]

For what it's worth I recently got a 2015 A4 loaner and noticed it didn't have any shudder. My 2014 S4 DSG w/ 19" wheels does have it though. Always thought it was normal.

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[MrFunk]

I've found that the quattro "grumble" is different depending on tires also. I would by no means call it a "shudder". It's barely noticeable in mine... My previous B6 A4 had it very loud. Soft all season tires or snow tires and it doesn't make the noise at all... stiffer summer tires yes.

[S4LI]

As I posted above, as of model year 2013 you should only feel this shudder in models with longitudinal manual transmissions. You shouldn't feel this in an S4 with S-tronic or an A4 with tiptronic etc. You can go down to your dealer and test drive anything from an A4 all to way up to an RS7 to see for yourself. I know this shudder very well. I lived with it for ~8 years in my B7 S4 6MT. The 2013+ S6, S7, RS7 and S8 don't do it and they have a lot more torque. The 2013+ S4/S5 with S-tronic doesn't do it nor does the RS5. When I was in the market for my RS5, I test drove a 2013 S5 S-tronic and the young and eager sales guy who actually knew the cars he was selling made a point of taking me to a parking lot and do some full lock circles to demonstrate how this car doesn't have this shudder anymore.

Between this thread and the above linked thread, it appears that there are several people on here who are experiencing it with their B8.5 (2013+) DSG S4s, so not 100% accurate that B8.5 DSG cars are free from Quattro shudder.

[pdqgp]

I've found that the quattro "grumble" is different depending on tires also. I would by no means call it a "shudder". It's barely noticeable in mine... My previous B6 A4 had it very loud. Soft all season tires or snow tires and it doesn't make the noise at all... stiffer summer tires yes.

Agree. It's more of a light scrubbing sound IMO. Normal.

[justr0]

Yeap, my 2014 S4 DSG with 19" wheels does this as well

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[bhvrdr]

Between this thread and the above linked thread, it appears that there are several people on here who are experiencing it with their B8.5 (2013+) DSG S4s, so not 100% accurate that B8.5 DSG cars are free from Quattro shudder.

Correct. I have a MY2015 with DSG and it of course does it. The crown gear center diff is not going to eliminate this. It can be a bit more noticeable from car to car but its normal.

Mike

[viceroy1976]

What size wheels/tyres did the A4 loaner have?
I've found that cars with 17" dont exibit as much quattro bite as say 19" with wider tyres.
My 2009 A4 quattro did exhibit quattro bite as does my 2010 S4, both with 19" 255 wide rubber.

[anerbe]

Vibration you feel is the very minor variation in the front curved path vs. rear. In this car's case, neither the front or rear follow the driven axle, as both are running. The electronic awd systems normally only have power to one axle until needed, so these often don't exhibit this.

Summer tires with little flex/hard rubber will not bend, and end up skipping over the road surface causing vibrations vs allowing very little amounts of slip. Summers also do not have much dampening at all, so any vibration is transmitted to the vehicle. Its much more pronounced in the cold, where summer tires will actually jump across the ground causing large pops and the vehicle will shift around during parking lot turns.

A/S and winter tires have much more dampening and progressive slip. I don't get any of the vibrations with my winter tires on.

[MVR 155]

As I posted above, as of model year 2013 you should only feel this shudder in models with longitudinal manual transmissions. You shouldn't feel this in an S4 with S-tronic or an A4 with tiptronic etc. You can go down to your dealer and test drive anything from an A4 all to way up to an RS7 to see for yourself. I know this shudder very well. I lived with it for ~8 years in my B7 S4 6MT. The 2013+ S6, S7, RS7 and S8 don't do it and they have a lot more torque. The 2013+ S4/S5 with S-tronic doesn't do it nor does the RS5. When I was in the market for my RS5, I test drove a 2013 S5 S-tronic and the young and eager sales guy who actually knew the cars he was selling made a point of taking me to a parking lot and do some full lock circles to demonstrate how this car doesn't have this shudder anymore.

Sorry but you are wrong, the crown center differential does not eliminate this light shudder/scrubbing at low speed/sharp turning maneuvers. My 2013 (which I purchased new) does this and before purchasing I drove 2 other cars that also did it. I have driven a 2014 S4 that also did the exact same thing. There have been multiple threads on this topic and this behavior is extremely "normal" for this car. I have not driven an RS5 (which I see you own) so I cannot comment from my own experience but given the 4 different B8.5 S4 cars I have driven I will tell you that it still is a characteristic of the car.

[anerbe]

Sorry but you are wrong, the crown center differential does not eliminate this light shudder/scrubbing at low speed/sharp turning maneuvers. My 2013 (which I purchased new) does this and before purchasing I drove 2 other cars that also did it. I have driven a 2014 S4 that also did the exact same thing. There have been multiple threads on this topic and this behavior is extremely "normal" for this car. I have not driven an RS5 (which I see you own) so I cannot comment from my own experience but given the 4 different B8.5 S4 cars I have driven I will tell you that it still is a characteristic of the car.

I've also driven an S6 extensively, and on full lock it also had a vibration.

Considering the severity of the shudder is subjective, what's normal for some is a problem for others.

[Thurston]

Brought my car in today to have a leaky motor mount replaced under warranty. They gave me a new A4 as a loaner.

My 2013 S4 has always exhibited a pronounced low speed "Quattro Crawl" vibration/diff shudder when cutting the wheel and accelerating at parking lot speeds. Multiple Audi dealers have confirmed that it's normal and it's just the diffs catching up to the change in speeds of the turning wheels. That said, the A4 loaner is also a quattro and no matter how hard I cut the wheel or how I drive it, I get no shake/shudder at all from the center diffs. My friends 2.0T C7 A6 also doesn't do the diff/shudder thing. So is it really an S4 thing or is it on a car by car basis? Anyone go from an A4 to an S4 and notice this pronounced difference?

OP this is totally separate from your question, but a "leaky motor mount?" I have never ever heard the term motor mount mentioned in the other car communities i've been a part of and to see it so often in the S4 community and now to see that an A4 also can have these motor mount issues.. I know it's not a big deal but I mean why are these engine mounts in Audi's going bad after so long?? What do i not understand about motor mounts that Audi also seems to not understand while everyone else does and gets it right? I keep seeing motor mounts for sale and this and that and I truly just can't fathom having to replace the mounts my engine sits on... help me here understand why motor mounts are failing albeit sparingly in A4's and S4's? edit: - i see it wasn't an a4.

[S4LI]

OP this is totally separate from your question, but a "leaky motor mount?" I have never ever heard the term motor mount mentioned in the other car communities i've been a part of and to see it so often in the S4 community and now to see that an A4 also can have these motor mount issues.. I know it's not a big deal but I mean why are these engine mounts in Audi's going bad after so long?? What do i not understand about motor mounts that Audi also seems to not understand while everyone else does and gets it right? I keep seeing motor mounts for sale and this and that and I truly just can't fathom having to replace the mounts my engine sits on... help me here understand why motor mounts are failing albeit sparingly in A4's and S4's? edit: - i see it wasn't an a4.

To clarify, my car is an S4, not an A4. No clue why this thing failed and I've never had an issue before (this S4 is 1st German Car) but Audi didn't seem surprised and they had no issue fixing it under warranty. I think it would be around $700-1K fix without warranty. My car has 36K Miles and is CPO.

[S4LI]

What size wheels/tyres did the A4 loaner have?
I've found that cars with 17" dont exibit as much quattro bite as say 19" with wider tyres.
My 2009 A4 quattro did exhibit quattro bite as does my 2010 S4, both with 19" 255 wide rubber.

Both cars have 18s with all seasons. A4 on stock tires, S4 on DWS.

[hotleadsingergu]

It's normal for all AWD systems. It's lessened with the crown gear centre diff, but not eliminated. I have a 2015 S4 and have it every time I pull out of my driveway in the morning or out of parking spots at a tight angle.

This isn't just an Audi thing...drive a Subaru and you'll feel the same thing. As I said, the modern Crown diff cuts it down quite a bit...but it's still there. Just feels more like a rubbing now.

[tgsweat]

My 15 does it. I also have a friend with a Range Rover and it does the same exact thing except even louder lol

[superswiss]

Sorry but you are wrong, the crown center differential does not eliminate this light shudder/scrubbing at low speed/sharp turning maneuvers. My 2013 (which I purchased new) does this and before purchasing I drove 2 other cars that also did it. I have driven a 2014 S4 that also did the exact same thing. There have been multiple threads on this topic and this behavior is extremely "normal" for this car. I have not driven an RS5 (which I see you own) so I cannot comment from my own experience but given the 4 different B8.5 S4 cars I have driven I will tell you that it still is a characteristic of the car.

That hasn't been my experience in the past 2 years. I've driven several brand new Audis during this time. Perhaps it's still there, but to a such lesser degree that I simply don't notice it anymore. This is one of the things that annoyed me with the B7 S4 and I immediately picked up on the difference of the newer generation Quattro system. It's one thing that I love about the newer Quattro system. It's smoother and more agile across the board. Evidently, OP can't feel it on the A4 loaner either, otherwise we wouldn't be talking about it.


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[hotleadsingergu]

That hasn't been my experience in the past 2 years. I've driven several brand new Audis during this time. Perhaps it's still there, but to a such lesser degree that I simply don't notice it anymore. This is one of the things that annoyed me with the B7 S4 and I immediately picked up on the difference of the newer generation Quattro system. It's one thing that I love about the newer Quattro system. It's smoother and more agile across the board. Evidently, OP can't feel it on the A4 loaner either, otherwise we wouldn't be talking about it.


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Interesting, because the new A4s don't even use the Crown Gear centre diff...they still use the Torsen T-3. It's used the same centre differential in all B8 models.

Just because he can't feel it doesn't mean it's not there. He might just not be feeling it because the car is made to be more comfortable, with vibrations and such being less apparent. I promise you, since it's only a byproduct of AWD systems, that it's there.

[superswiss]

Interesting, because the new A4s don't even use the Crown Gear centre diff...they still use the Torsen T-3. It's used the same centre differential in all B8 models.

Just because he can't feel it doesn't mean it's not there. He might just not be feeling it because the car is made to be more comfortable, with vibrations and such being less apparent. I promise you, since it's only a byproduct of AWD systems, that it's there.

It is my understanding that the B8.5 tiptronic has an updated center differential. It's actually not the crown gear. The crown gear is only used in the S-tronic, but the new tiptronic diff is based on the same principals as the crown gear. Loaners are typically automatic, so I assume this loaner has the tiptronic.


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[S4LI]

It is my understanding that the B8.5 tiptronic has an updated center differential. It's actually not the crown gear. The crown gear is only used in the S-tronic, but the new tiptronic diff is based on the same principals as the crown gear. Loaners are typically automatic, so I assume this loaner has the tiptronic.


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Yeah the loaner is tiptronic 2.0T A4. Anyway, seems that most if not all B8.5 DSG S4 owners notice this to one extent or another, so let's just call it "normal" and move on....

[scottycs]

another '13 S4 with it.

[SteveYem]

For whatever it's worth, I had a B8 6MT (2012) S4 that exhibited this behavior, and my B8.5 6MT (2015) S4 does the same thing.

[Loe]

interestingly, I never felt this rubbing on my B6 S4 (Torsen with the 50/50 split), but its definitely there in my crown-diff S5. Its more of a "low-bassy" noise though, but does resonate throughout the cabin. It's by no means intrusive, but is there.

[ronbars]

My 2013 S6 has done this since day one and I don't find it to be troublesome.

[RWD2quattro]

My car had zero low speed vibrations till I installed the upgraded 034 density tranny mount. It's pretty bad at around 15-20mph on decel.
I guess if you want performance, you have to have compromises...

[hotleadsingergu]

My car had zero low speed vibrations till I installed the upgraded 034 density tranny mount. It's pretty bad at around 15-20mph on decel.
I guess if you want performance, you have to have compromises...

Not even remotely the same thing. This isn't a performance thing.



I really want to stress this: Any AWD automobile with a tighter turning radius will exhibit this behavior. It might be strong, it might seem week, but it's there. There's literally nothing you can do about it...it's physics. Jump in any Subaru, crank the wheel all the way to the left, and press the gas -- you'll feel the same thing.

Also, the Torsen T-3 and the Crown Gear are not the same thing. Same idea, but different application. The Crown Gear is vastly superior, which is why the Quattro system in the modern S4/S5s is so much better than the A4/A5s. I'm pretty sure it's also in modern A6, A7, and A8s.

[DBL R]

http://blogs.youwheel.com/2015/02/25...wagen-4motion/

A good read for anyone who is still confused and who thinks that all Quattro is created equal.....

[oldmane]

does the regular a4 even have a dsg? i thought it was a regular slushbox.

[xtremepsionic]

I'm pretty certain this tight turn low speed noise/vibration is tire grip dependent.

The reason why this happens is that the front and rear axles are partially locked due to the 40/60 center diff power split, this causes the wheels to try to turn at approximately the same speed. But when you're at full steering lock, the wheels would need to travel different paths and distances. If your tires have good grip they'll tend to start skipping on the pavement a bit if the diff doesn't allow it to turn at the speed it wants to.

I've found that since I've put winter 17" tires on the S4, the noise and vibration at low speeds are pretty much gone. With summer 19" this noise happens all the time.

[HeymyAudi]

My 2013 S4 does it.. I test drove 3 S4's before (13,14 and 15 new) and they all did it... My A4 Loaner with 200 miles I had last month did it as well...