Evoque major transmission problem but just 26k miles

MrGrumpyOldMan

silverfox777 said:

We had a Discovery sport for 3 years from new. 3 days out of warranty auto gearbox started slipping so called JLR. They were really unhelpful and disinterested so would definitely not purchase another. 18000 miles and fully serviced by JLR on a service plan.

sorry to hear that. From my experience I'm not surprised in the lack of response from JLR. Neither will I buy another LR

Goudy

daveyjp said:

Goudy said:

daveyjp said:

If this is 4wd the diff can be affected if tyre wear is uneven.  Have tyres been swapped across or around axles regularly?

If it can break the diff if the tyres are worn differently and their diameters are millimetres off.

How does the thing go arounds corners without exploding the diff when wheels are expected to turn differently by in some cases, metres.
Turn a 90 degree corner and the outside wheels will turn far more than the inside, yet a couple of mm difference in tyre wear ruins the diff?

Seems like an poor excuse to put the blame back on the owner.

As above.  The lower end Land and Range Rovers use a Haldex clutch for 4wd operation.  The car is predominantly FWD, but when traction on FWD is poor the clutch is  engaged to operate the drive shaft to the rear wheels.

With significant tread depth difference between front and back there can be a speed mismatch.  The Haldex can be engaged far more than expected and at higher speeds.

From an owners experience

This also leads me on to mention the other important way of protecting your drivetrain, tyres. Make sure they are all the same make, model, size, have the same tread depth remaining and the same air pressure. If you imagine a low tyre on one side which makes the Haldex computer think the tyre is moving faster than the others, and therefore it believes a wheel is slipping and it will engage the four wheel drive system to compensate the difference in the rotational radius’. What you end up with is a strain on the drivetrain. 

Our change of tyres had been what caused all the damage. The larger tyres on the front made the system think our rear wheels were constantly slipping. This had caused the splines to go on the transfer box – caused by the sudden demand from the Haldex to engage the 4×4 system at a higher speed than you would ever being doing in an offload situation where you would require the 4×4 facility – and, yes, there is still more to come, it also caused a bearing to collapse in the rear differential causing it to make a humming noise as we drove – not that we could hear this over the noise of the transfer box damage.

I still thinks this sniffs a bit like the back end of a cow.
I'm not saying that is not happening, but it's a poor excuse that blames the owner/driver rather admit they f'd up.

They've made a car that doesn't allow for the wheels to turn at different speeds without ruining the drivetrain?

Plenty of cars use Haldex clutches to meter out power to the rear axle, Audi have been doing it for 40 years with plenty of success.
Even Fiat use the same system in their Panda 4x4 without this issue.

I say it again, it's a poor excuse for a manufacturing problem if the Haldex computer can't cope with the wheels turning at different speeds on the road due to a millimetre or two of tyre wear.
It's not like the engineers didn't expect the tyres to wear at different speeds on different axles.

In fact, it pretty easy to work out.
A common Evoque tyre size is 235/60r18.
That's a diameter of 739mm and a rolling circumference of 2320mm.
Tyres come with around 8 mm of tread and minimum tread depth of 1.6mm, so would lose around 6.4mm in diameter.
732.6mm diameter means is loses just 18.5mm in circumference or less than 0.8% of the max circumference of a new tyre, but it probably won't be as much as all tyres will wear, just at different speeds.

I can understand forcing (manually selecting) the centre diff to lock up for off road driving when actually on the road (all wheels have plenty of grip) can wind up the transmission as the wheels won't slip on the ground, but designing the system that allows that to happen to extent of ruining the drivetrain without forcing it to lock up on the road is just a bad design. Others have managed it successfully.

MEM62

MrGrumpyOldMan said:

This should not happen to a car of that age and mileage.

Except if you own a Range Rover - a brand well known for reliability issues.