Hi,

So I've got this Yeti 4x4 with the Haldex 4th generation clutch. Now I want to know something about tyre wear. In the early days, when a Haldex was a pure mechanical device, it was important to keep tyre wear differences between tyres all around at a max of 2mm to avoid permanent clutch engagement, with damage on the long run. Is this still true? The owner's manual doesn't mention anything about this.

Paul

Excuse my ignorance, but why would a 2mm difference in tread depth cause the Halsex to engage permanently?

Not an answer to your question, but my 4x4 Yeti had 4 new tyres at last fitting and the fronts are worn more than the rears. Less than 2mm difference, by quite a bit.

I doubt that, from new, you'd get more than a 2mm difference between the front and rears before the fronts need replacing.

My plan is to swap front and rear and buy 4 new ones when any one of them gets close to the minimum (i.e. Below 2mm tread left).

KB, the comments about tyre size difference applied to the 1st generation Haldex, as it sensed there was a "slippage" problem so engaged permanently. It was soon programmed out with subsequent generations. The original Freelander had a similar problem with it's viscous coupling.

 

Paul, don't worry about it, it doesn't apply now. On my car it has always been that the fronts that wear out first, so I just put swap the backs to the front and put 2 new tyres on the back. Only once have I had to buy 4 new tyres, when they all wore out together. Doing it this way has caused no problems to the drive system. 

Like Graham said, there is no problem with the Haldex 4 or 5 and tyre wear. On the other hand, I have a little problem with the idea of not rotating the tyres front to back to equalize the wear on all 4. The front do do most of the work, traction, steering and braking, and therefore wear faster than the rear. Ideally all four tyres should be alike for best handling. This is best achieved by swapping front to back when changing winter and summer tyres. 

 

Tyre development is so rapid these days, so that the tyres you bought two or three years ago are no longer available and the newer ones have different slip angles, so having diffeent tyres front to back can introduce some weird handling characteristics at a time when you do not need any surprizes.

 

The old idea of having the best tyres on the rear was OK in the days of resr wheel drive. But, today in a Yeti with intelligent 4WD it is no longer valid IMHO. I typically replace all 4 with around 3 mm thread depth left.

My preference of changing front to back and evening out wear means that I have to buy four stars time and can usually get a better deal on them that way.

Sometimes 25% off, or 'Buy 3, get 1 free' (or 25% off) or £50 fuel voucher. And I prefer to have all four tyres the same - not because I can notice any difference with mixed tyres, but because I just prefer it that way (probably the OCD part of me).

I have read somewhere that Haldex can cope with 4% permanent difference. If tyre dimension on all 4 wheels are the same, it is not possible that different tyre wear will be near this value. It is of course preferable that tyres wear are equal on all four wheels, but in practice it has no negative effect on the Haldex. It must anyway cope with different rotations all the time, as all wheels travels different distances (speeds) in turns.

OK guys, thanks for your insights. I knew this forum was the right one.

For those that are not similar with the first generation Haldexes : if the difference in thread depth was more then 2mm the haldex would be slipping so much that the oil within would stiffen, thus creating way too much tension in it. As a result and over a longer period the clutch would break down.

I must be that the developers found a way to cope with this problem.

My preference of changing front to back and evening out wear means that I have to buy four stars time and can usually get a better deal on them that way.

Sometimes 25% off, or 'Buy 3, get 1 free' (or 25% off) or £50 fuel voucher. And I prefer to have all four tyres the same - not because I can notice any difference with mixed tyres, but because I just prefer it that way (probably the OCD part of me).

And doing that at least means you get max. mileage out of the set.

 

As said, many tyres go out of production - I couldn't even get a particular tyre 12 months after I bought one car - I guess the manufacturers buy up a big batch of tyres near the end of their production run in some cases to get a better deal? And on one Passat I had 4 tyres fitted to give a matched set even though I had plenty of tread left on the rears.

 

Sometimes it's recommended by manufacturers not to swop front to rear, what's the score with the Yeti?

Sometimes it's recommended by manufacturers not to swop front to rear, what's the score with the Yeti?

 

Swap front & rear every 10,000km - see under "Replacement of wheels" in the "Wheels" section of the owner's manual.

Swap front & rear every 10,000km - see under "Replacement of wheels" in the "Wheels" section of the owner's manual.

Like this, on page 203:

"If significantly greater wear is present on the front tyres, we recommend changing the front wheels around with the rear wheels as shown in the diagram ⇒ fig. 162.

You will then obtain approximately the same life for all the tyres. It may be advantageous to swap the tyres over “crosswise” when uneven wear characteristic arise on the running surfaces of the tyres (but not in the case of unidirectional tyres). We recommend that you contact an authorised ŠKODA Service Partner. They have extensive knowledge about the possible combinations. We recommend that you change the wheels around every 10 000 km in order to achieve even wear on all wheels and to obtain optimal tyre life."

 

But , after some days of thought, it still hunts me. "If" the oil used in the 4th gen Haldex clutch is the same oil that was used in the 1st gen, then this means that the oil still stiffens up when it gets stirred too much (like when more then 2 mm tyre wear). This is a plain hydromechanical phenomenon and I really don't understand how this can be avoided in the modern Haldex clutches.

When I change to winter tyres, I mark the normal tyres so that when they go back on in spring, they go back swapped front to back and visa versa.

Same with the winters.

All 4 tyres on each set have the same amount of tread left.

Happy days.

When I change to winter tyres, I mark the normal tyres so that when they go back on in spring, they go back swapped front to back and visa versa.

Same with the winters.

All 4 tyres on each set have the same amount of tread left.

Happy days.

I did the same with my Yeti. The overall difference between the front & rear sets, for both summer & winter tyres, was no more than 1mm. I'll be swapping my all seasons front <==> back as well, just to keep wear even.

When I tried swapping Dunlop SP's front to rear , the row was so bad that I had to swap back. My tyre dealer says they no longer advise such swaps due to wear patterns being different.

I've heard that one before. Some say that each tyre has its own wear pattern, and that can cause trouble when you put the wheel somewhere else.

When I tried swapping Dunlop SP's front to rear , the row was so bad that I had to swap back. My tyre dealer says they no longer advise such swaps due to wear patterns being different.

My Dunlops were swapped every year, though only did six months service each time before winters were put on. I never detected any difference based on which went on what axle, other than the winter tyres (Nokian WR A3s) were quite different to the Dunlop SP01s. The wear pattern on both front & rear tyres was just the same, with slightly more front than rear wear. The reason there was that 1mm difference is that a pair of the tyres had done two seasons at the front vs the other pair that had done one.

 

I've read on here about people who swapped tyres round and had issues, but that seems to have been issues with the alignment/geometry of the wheels leading to irregular wear, which causes noise and/or poor handling when moved to the other axle. I had slightly higher wear at the edges (both front & rear) than the centres, but given my fondness for throwing it round roundabouts that's not too surprising! There's been no trace of saw-toothing or any of the the other common uneven wear issues.

 

I think it would be worth getting your alignment checked in case one of the many potholes Yetis attract has caused problems.

My Dunlops were swapped every year, though only did six months service each time before winters were put on. I never detected any difference based on which went on what axle, other than the winter tyres (Nokian WR A3s) were quite different to the Dunlop SP01s. The wear pattern on both front & rear tyres was just the same, with slightly more front than rear wear. The reason there was that 1mm difference is that a pair of the tyres had done two seasons at the front vs the other pair that had done one.

 

I've read on here about people who swapped tyres round and had issues, but that seems to have been issues with the alignment/geometry of the wheels leading to irregular wear, which causes noise and/or poor handling when moved to the other axle. I had slightly higher wear at the edges (both front & rear) than the centres, but given my fondness for throwing it round roundabouts that's not too surprising! There's been no trace of saw-toothing or any of the the other common uneven wear issues.

 

I think it w

could be worth getting your alignment checked in case one of the many potholes Yetis attract has caused problems.

Wear on my tyres is equal across the treads. Difference between front and rear axle sets is only about 1mm with about 3mm still n the rears. I will replace all 4 shortly.

When I tried swapping Dunlop SP's front to rear , the row was so bad that I had to swap back. My tyre dealer says they no longer advise such swaps due to wear patterns being different.

 

Nothing about that on Dunlop's web site: https://www.dunlop.eu/en_gb/consumer/learn/rotating-your-tires.html

 

My experience with swapping my SP01s front to rear has been almost exactly the same as dbg400's: no issues whatsoever.

 

(I did notice when I put my winters on this time that a balance weight seemed to be missing - but on reflection that might well have been the wheel that had its tyre repaired over the summer, and it was probably re-balanced then.  I certainly hadn't noticed anything amiss when driving on it.)

off-topic, are those SP0s1's so extraordinary good or is there just one type of tyres that fits on 225/50's ? My Yeti has them too....

off-topic, are those SP0s1's so extraordinary good or is there just one type of tyres that fits on 225/50's ? My Yeti has them too....

 

The Yeti has come on various tyres as standard. including Dunlop, Goodyear and Pirelli.

There are numerous makers in that size, for example I use Kumho's.

They were the standard UK fitment for most Yetis, though I think Pirellis were used more recently. The 225/50/17 size doesn't seem to be that common, so some of the tyres popular on other models (I was interested in getting the Goodyear Eagle 1 Asymmetric 2's) aren't available. The SP01 is a good tyre, but not necessarily a great one. All season tyres have been a popular replacement once the time came - there are quite a few running on Goodyear Vector 4Seasons.

But , after some days of thought, it still hunts me. "If" the oil used in the 4th gen Haldex clutch is the same oil that was used in the 1st gen, then this means that the oil still stiffens up when it gets stirred too much (like when more then 2 mm tyre wear). This is a plain hydromechanical phenomenon and I really don't understand how this can be avoided in the modern Haldex clutches.

Haldex is not and has never been a viscous clutch. It has wet multi-clutches and will be activated by pressing the clutches together by oil pressure. The activation has been more and more sophisticated from gen.1 to the latest gen.5. Now it is electronically controlled and monitored from several inputs but the main source is speed difference of the axles.

Gen.4 and gen.5 is a little different than previous generations. Borg Warner has taken over, the Haldex is now "proactive", meaning that the rear axle can have positive drive all the time. The electronics monitors several parameters, like throttle position, steering wheel turn, ABS and more, and preloads the clutches to give positive drive to the rear axle before any wheels spins. This site gives good info:

http://www.awdwiki.com/en/haldex/

I don't know if gen.1 suffered from use of any "wrong" oil, but it has never been the intention that it should be the oil within the multi-clutch package which engaged the rear wheel drive.

So, as long as you have the same tyre dimension on the car, there are no way that different tyre wear would harm the Haldex whatsoever. The difference is so little, a worn tyre has 1% less radius than a new one.

Edited 31 December, 201510 yr by fatzy

Haldex is not and has never been a viscous clutch.

Oho ! I didn't knew that. I simply thought that "haldex" was the new name - or a brand name - for the old "syncro". The syncro clutch was viscous. If it isn't viscous, it can't stiffen of course... thanks a lot for this insight!