Suspension and Chassis LSD on maximum turn manouvers

[asd]

Anyone else noticed that during parking manouvers on max wheel turn you can feel/hear one of the wheels biting/crunching the road happened to me a couple times, I guess during cold starts... Dunno if that's something to worry about or avoid at least?

 

[Scottukl]

It's normal with the LSD in an aggressive setting. Feels like you're 'fighting' the steering during low speed sharp turns. If you put the car in ECO and try the same thing it won't happen.

 

[jeroenvde]

cool! I will give this a try

 

[asd]

Happens when moving out in the mornings/afternoons, cold start and definitely in Normal mode setting, during slow moving sharp turn maneuvers...
I'm in doubt because last time I experienced something similar it was on a 4WD Kia Sorento, but it was after it had differential fault and it was repaired, I am unable to say if it occurred also before the failure or not...

The sensation has little to do with fighting the steering wheel, feels more like one wheel is getting a bit too much torque and is doing tiny slips kind of... it also reminds me a little of driving the wheel over a cable or a stick maybe.. hard to explain. Will try to do some more testing, if it turns out it's repeatable I'll head to Hyundai about it.

 

[Scottukl]

Low profile tyres can also cause this feeling through the wheel, I had it in my Subaru which was AWD while turning on full lock at low speed.
Shouldn't be a problem but hard to tell exactly what you are experiencing and if it's the same thing.
Hope it's all OK.

 

[asd]

Low profile tyres can also cause this feeling through the wheel, I had it in my Subaru which was AWD while turning on full lock at low speed.
Shouldn't be a problem but hard to tell exactly what you are experiencing and if it's the same thing.
Hope it's all OK.

Thanks, that's a little comforting, I'll be looking at it, and update this thread if there are any conclusions.

 

[speedking]

Mercedes-Benz had a similar issue with juddering in slow speed manoeuvres, but I suppose that was RWD, as you were.

I experience juddering on full lock when pulling off the drive, hasn't really concerned me.

 

[Gizmo]

I've noticed it when on very cold tyres (under maybe 10 celcius) - had it on my 370Z too, once the tyres have warmed it doesn't do it.

 

[alinturbut]

Noticed the same thing this morning, even opened a new thread (https://www.n-cars.net/forums/threads/differential-making-strong-cracking-noises.2127/)

 

[WookieeM]

Yep noticed this, the driving over a stick analogy is spot on.

I notice it every morning driving into work round a tight 90 degree slow bend.

Also noticed a couple of times when some loose gravel is on the road surface, sounds like a wheel spins a tiny bit.

Will try Eco setting (just for the softer LSD setting) as I drive everywhere in N Custom

If it stops then I can mess with custom.

Sound like it’s normal and not the car about to explode so no worries.

 

[Stash-N]

Can I assume then that in ECO mode the diff is "open" ? I can feel something through the car when on steering hard lock while manoeuvring the car at very slow speeds. I know how the old LSD work on older rear wheel drive cars but don't yet fully understand how the diff works on these cars.

Edit: Just had some time to look at how the eLSD works and I would guess that what I feel is some tyre chatter due to the diff oil being cold and the clutch pack being new. The diff is effectively slightly engaged given these set of circumstances. Yes, I may be stating the obvious to many of you however others may be too reserved to ask the question. I am happy to ask and answer if it helps someone.

 

[speedking]

The other thread is this one. The e-LSD only has 2 modes, NORMAL or SPORT, I don't believe that either of those is 'open'. Therefore you cannot prevent winding up the drivetrain on tight turns. It's how that energy is dissipated that determines whether you get the judder or not.

Mine is still juddering at 7500 miles, so it's not related to newness.

 

[asd]

Haven't tested thoroughly in different drive modes, doesn't seem to make a difference, but quite sure it only happens on cold LSD and/or tyres. It doesn't sound (and feel) as something healthy for either of those components so I'm trying to avoid it, but I'm not as worried it's something wrong/unusual. I suppose that is also why the N has a rather large turn radius -the eLSD... wouldn't trade the LSD for a better radius tho

 

[speedking]

Random thoughts:

From Hyundai Australia:

Electronic limited slip differential (Performance Package):
The electronically-controlled mechanical limited slip differential (E-LSD) distributes torque intelligently between the two front wheels depending on driver inputs, as well as the 2 selectable E-LSD modes (Normal and Sport). The E-LSD allows drivers to be more engaged with the vehicle, reducing wheel spin and understeer, increasing cornering speed, allowing the vehicle to be driven out of corners on the throttle with confidence.

So mechanical LSD. That implies clutches rather than fluid? Would be interested to know.

That explains why the clutch can't be disengaged to enable the diff to be open, if it was you would have no drive, at least to one half-shaft. You could have drive to the other side, but if that was spinning then you'd have no drive at all, but no worse than a standard open diff. Isn't that exactly the problem that the LSD is invented to overcome?

I could have a switch to make the diff open when I exit my drive, but I guess if it's not really a problem then it doesn't need solution, let alone a complex solution. </ramble>

 

[asd]

https://gaukmotors.co.uk/post/limited-slip-differential-lsd

A fair part of that goes over my head but it would seem that eLSD can only be mechanical... There is no "open" state (on our diffs?), hence the modes of the LSD do not include "off", the turn radius is worse than what you'd expect from a hatch and the tyre crunching sensation we are discussing here.

 

[asd]

Alrights, so today took a drive just long enough to warm the car up, arrived at a parking lot and when parking in reverse with wheels turned I got most of this happening ever, it felt more like abs engaged for a good 0,5-1 meters... Guess I'll be bringing this up with the dealer after all...

 

[speedking]

I can confirm that the LSD bumping happens no matter what drive mode you're in

 

[_Emma]

@speedking yep. Mine is awful. Half my tyres feel like they’re left on the road. Mentioned it when dropping it off today for the service. They think I’m a nut job again.

 

[WookieeM]

Mine did it a bit extra today, it was proper cold when I set off - Ice on windscreen.

Jumped as I left the drive, sharp right turn, and again at the end of the road, less sharp left turn.

Made wifey turn to me with a concerned look - Told her its normal, its a feature, we all have it.

Any dealer feedback welcome!!

It does it a bit some some mornings, but today was definitely worse.
Others have said LSD oil temp?

 

[asd]

Mine did it a bit extra today, it was proper cold when I set off - Ice on windscreen.

Jumped as I left the drive, sharp right turn, and again at the end of the road, less sharp left turn.

Made wifey turn to me with a concerned look - Told her its normal, its a feature, we all have it.

Any dealer feedback welcome!!

It does it a bit some some mornings, but today was definitely worse.
Others have said LSD oil temp?

Can't exactly figure it out, it happens mostly when cold, but sometimes I would start off with a sharp turn (on purpose, to check it) and get no judder, and as I wrote in my last post, got it once pretty hard on warmed up car when backing up... Done some search and seems this also occurs on some other awd or diffed cars... will try to investigate further, but I bet the dealer will tell me that's supposed to happen :/