Attention Sorrento XS owners

[JohnI.Stephen]

Hi all; a question for all you Sorento XS owners. Mine's an automatic, and with just under 2000 miles on the clock I have noticed a problem that I hope is merely annoying and not serious. When on hard or full lock left or right, from standstill, and moving away - even at very low speeds - I always feel some slight 'juddering' from the front two wheels. This stops the instant I have straightened up and does not occur in normal driving. However, as soon as I come to a stop; then turn left or right, the slight (but clearly perceptible) judder occurs.

It's as though the wheels were in Dif lock mode (although it doesn't have a dif lock?) and that the inside tyre is trying to go at a different speed to the outside tyre as each is on separate arc.

Any thoughts from other Sorrento owners?

John

 

[Pete4]

Hi Stephen,

I don't own a 4x4 but I think this is down to a feature called "wind up" or something like.

It's because the back wheels need to go slower than the front when turning circles. I don't know if you can disengage the 4 wheel drive but if so, you should do so when on tarmac as this is putting a lot of touque on the prop shafts.

Pete

 

[JohnI.Stephen]

Hi Stephen,

I don't own a 4x4 but I think this is down to a feature called "wind up" or something like.

It's because the back wheels need to go slower than the front when turning circles. I don't know if you can disengage the 4 wheel drive but if so, you should do so when on tarmac as this is putting a lot of touque on the prop shafts.

Pete

Pete; no the 4x4 is 'automatic' so that it's only supposed to bein in 4WD when required; other than that, 2WD; or so the manuals says ?!

 

[Pete4]

Hi Stephen,

I don't own a 4x4 but I think this is down to a feature called "wind up" or something like.

It's because the back wheels need to go slower than the front when turning circles. I don't know if you can disengage the 4 wheel drive but if so, you should do so when on tarmac as this is putting a lot of touque on the prop shafts.

Pete

Ah, I'll leave it for someone who knows what they're talking about then ;-)

 

[sparkes]

John

Take the car back to the dealers and ask them to check the front CV joints for correct grease levels. If it starts making a noise when turning, get it recovered to the dealer.

Steve

 

[Damian]

John, there is a probable reason for this, as I have had similar problems with my vehicle, though not a Sorrento.

If you have wide profile tyres fitted, when you go on full lock, the tyres dont like it and scrub the outer edges, almost as if they "tuck under", also, the juddering may be caused by the p.s pump pulsing , as it is recommended to not use full lock as much as possible. Check the outer edges of your tyres and if they are feathering , then its the tyre size causing the problem, and you will just have to avoid full lock if you can.

It is very expensive and very annoying to have to change tyres when most of the tread is fine, but your down to the canvas on the edges.

 

[JohnI.Stephen]

I sriously don't belive it to be a tyre issue; taht would sound and feel diferent. The 'juddering' comes from the wheel as oppsoed to the tyres. Also we are not discussing 'full lock'; it occurs when turning normally but only from a stand-still.

Have any Sorento XS owners expereinced this please?

John

 

[trevor11sqdn]

Hi John, sorry to hear of your problem,, I have the XS which has now covered 16000 miles and is in use every day. I cant say that Ive experienced any thing like you describe, but I do try to go easy on full/hard lock. In fact I have had little or no problem at all with the Sorento. (Touch wood). Get it looked at by the dealer, at least it is an easy fault to replicate. Good luck.

 

[JohnI.Stephen]

Thanks for the suggestions. I think I do need to see the dealer. So thanks again to all who replied.

John

 

[clivea]

Hi,

I have an 04 XS auto and have had no problems with it stereing from a start, or when on hard lock, although as advised by the handbook I do try and avoid hard lock if I can.

 

[Tony A.]

hello mate I own a late 03 xs never felt anything like your description .all the best TONY A.

 

[JohnI.Stephen]

It's as though the froint wheels needed to be 'engaged' or synchronised and, sor a second or so, there's a distinct (but minor) judder. Yes, I really must get it soretd out at the dealer's. Thanks

John

 

[JohnI.Stephen]

I have just been advised by a 'Kia Mechanic' on the KIA-Forum the following :

"I'm not sure what package the SX/XS is compared to the US version, but I'm guessing both of you have the TOD (automatic) 4x4 system?

If so, this is normal. A lot of people voice their concerns over this. About the only advice I can offer you is to make sure your tire pressure is correct. The overall tire diameters should be close to the same size, and tire pressure affects this. "

Thansk to all who offered their views

John

 

[JohnI.Stephen]

This is a further explanation from the KIA Mechanic on the (American) KIA Forum which I think finalises the issue and closes this thread. Thank to all - John

______________________________________________________________

The TOD control unit uses information from the wheel speed sensors to determine how much to engage the magnetic clutch in the transfer case. When you're turning the front wheels, all of the wheels are turning at different speeds so the control unit "sees" that some of the wheels are slipping because the RPM's are all different. The control unit compares front to rear, so whenever at least one of the front wheels is rotating slower than at least one of the rear wheels, the control unit engages the clutch until they equal each other (up to a 50:50 split of power).

For example, say you're turning slowly all the way to the left:

(not real numbers)

Front left wheel:1 RPM

Front right wheel:2 RPM

Rear left wheel:1 RPM

Rear right wheel: 2 RPM

The front left wheel is turning at 1 RPM slower than the rear right wheel, so the control unit thinks that wheel is slipping and will engage the 4wd. The magnetic clutch will engage and slip less (tighten more) until the wheel speeds are closer to the same. The vehicle always operates the rear wheels, so the transfer case can only "add" the front wheels into the equasion until the wheel torque (power) is equally split.

The wheel speed sensors are very accurate, so you don't have to move any of the wheels 1 full revolution before the TOD kicks in. I did a few tests for a post on this forum and found that the TOD would kick in almost instantly (1/4 turn) after the wheel speeds became different, so everything happens very quickly.