N/S/R wheel locked on my 4Mo

[BeePee]

This isn't good, I've done millions of miles in works vans over the years and today is my turn to breakdown......IN MY OWN VAN !

T6 204 4motion

As I pulled away this morning I felt and heard a noise at the rear, I stopped and got out to look, the rear wheel had skidded slightly at less than 5mph, no handbrake on in case you ask.

Currently waiting on VW Assist.

Dashboard fault light now on

 

[Dellmassive]

4M Haldex issue?

Keep us posted

 

[BeePee]

The VW tech scanned the system and no fault was stored but the 4x4 light is flashing on the dashboard.
It seems the rear diff is active and when I turn it obviously makes the wheels fight against each other.

Recovered and away to the dealer. It will be tuesday before they can have a look at it.

 

[Insert Coin]

Sounds a little worrying, generally the 4-Morion seems bullet proof, very rare to read of any issues.

 

[BeePee]

My thoughts exactly, I reckon electrical and a solenoid isn't receiving the signal to disengage rather than mechanical failure.
It was driving ok the day before.
Possibly related to the electrical failure of the central electronics module in the rear when it was water damaged. (o/s sliding door recall for water ingress by VW, the recall was completed but not properly and damage occurred as a result a month later)

 

[BeePee]

I had them on the phone today, they.ve managed to get it in the workshop early, "did you know you've got different sized tyres front and back ?" Yes, they're matched for rolling circumference and wheel width, am no a dafty !

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0.1% match which as advised is well within tolerance, in fact a slightly worn front to back tread depth is probably worse than 0.1%

Front wheels are 8.5J x 20 with 245x45x20 Uniroyal Rainmaster
Rear wheels are 10Jx20 with 275x40x20 Uniroyal Rainmaster

OK, diff oil out and clutch plates out ? It's special oil and they need to order it in, rebuild and test........Tuesday

 

[Loz]

This isn't good, I've done millions of miles in works vans over the years and today is my turn to breakdown......IN MY OWN VAN !

T6 204 4motion

As I pulled away this morning I felt and heard a noise at the rear, I stopped and got out to look, the rear wheel had skidded slightly at less than 5mph, no handbrake on in case you ask.

Currently waiting on VW Assist.

Dashboard fault light now on
View attachment 117539

Not the Difflock then?

 

[Pauly]

Bit of a weird one this, i have a basic understanding of haldex but not sure how it can lock one wheel ?
Be interested to hear what the diagnosis and remedy is

 

[DaveD]

Not the Difflock then?

Still sounds like diff lock engaged. Although I'm not a fan of different sized wheels on a 4 Motion no matter what the internet says, I just wouldn't do it.

 

[mmi]

The VW tech scanned the system and no fault was stored but the 4x4 light is flashing on the dashboard.
It seems the rear diff is active and when I turn it obviously makes the wheels fight against each other.

Never seen any Haldex-fault to turn on any warning light or other messages on dash. There have been cases when Haldex-clutch has been fully inoperative and still no warnings on dash. However, relevant faults have always been present in fault memory.
In my book the dash light indicates only the following:
- steady light - diff lock engaged (locked);
- flashing light - diff lock "activation or deactivation" in progress (respectively not yet locked, or still locked).

 

[DaveD]

As I pulled away this morning I felt and heard a noise at the rear, I stopped and got out to look, the rear wheel had skidded slightly at less than 5mph,

When that happened were you applying steering lock, i.e. turning?
When the rear differential is locked the rear wheels turn at exactly the same speed and if you are trying to turn, then one of two things can happen, either you will understeer, i.e. carry straight on, or one rear tyre will break traction by skidding or spinning. (Usually the inside rear tyre will spin off some of the excess drive input). The second option is what I suspect you experienced.

 

[BeePee]

I know how a differential works and to me it seems like it has been activated (locked or otherwise by a faulty solenoid?)
@mmi Remember I had the recall done on the side door for water ingress then a few months later all the electrickery issues with central locking electronics etc, "we found the side door leaking and allowing water in to the electronics", yeah, you completed the recall, remember ?

To me it seems related somehow, my mate works on a lot of 4motion Transporters for a windfarm company, they're overloaded constantly and yeeha'd up rough roads, he's replaced a couple of Haldex units as a result but that's abuse.

@DaveD Was ok creeping forward straight but as I turned (my driveway has a right turn then a left turn) that is when i felt it grab the dry tar.

 

[DaveD]

@DaveD Was ok creeping forward straight but as I turned (my driveway has a right turn then a left turn) that is when i felt it grab the dry tar.

I'm sticking with differential locked, as per your post 5.

 

[Littleblackflash]

Did it lock both wheels or just one?

Edit - just noticed the post title NSR. I can't see how the clutch plates on the new Gen5 haldex can lock one wheel. I thought the clutch plates were now on the input to the diff, not on the diff output shafts. Unless your have diff lock option which does have clutch plates (or syncho) to lock the output shafts together. Either way I can't see how one wheel would be locked.
Are you sure it's not a failed wheel bearing or the brake locked on one side?

I'm interested to know what the root cause was. I agree the wheels shouldn't make any difference.

 

[BeePee]

Only locked one wheel whichever way I turned to go out my driveway, I have an S shaped drive.

Just heard from VW

New Haldex required, there is swarf in the diff !!

 

[BeePee]

Further call from VW, covered under warranty but not again if I run staggered wheels !
I'll be selling my Axe EX30 wheels as soon as I get my Kombi back ! Recently had new front tyres and black copper powder coating done.

I wonder if having wider rears than fronts have been a contributing factor ?

Any Sportline or Duchy wheels for sale ?

 

[Littleblackflash]

I can't see how the staggered wheel have a significant effect, but I can understand it could be a small effect so their offer to replace it once is fair. The tyre width will have very little effect but its probably wise to get matching tyres front and rear.

I'm glad they are sorting your van and good luck getting some nice new wheels.

 

[DaveD]

Further call from VW, covered under warranty but not again if I run staggered wheels !
I'll be selling my Axe EX30 wheels as soon as I get my Kombi back ! Recently had new front tyres and black copper powder coating done.

I wonder if having wider rears than fronts have been a contributing factor ?

Any Sportline or Duchy wheels for sale ?

Fair play to VW, they had an easy excuse to get out of paying so all credit to them, you've had a very good result!

 

[BeePee]

OK, update time,

I got my Kombi back today surprisingly, parts cleared customs on Monday and were at the dealers on Tuesday.
New Haldex and associated parts installed and they went to test drive but the diff was still locked after all of the electrickery and mechanical fittings were plugged in, a faulty solenoid was found and replaced !!!! (remember the electrical issues recently after the rhs door recall sealing let water in and damaged the central management thingy?

As the service receptionist was reading out the report I said "ah so a faulty solenoid has activated the diff?" ..............she went a bit silent and moved on swiftly to get me into my van !


Thoughts ?

 

[DaveD]

OK, update time,

I got my Kombi back today surprisingly, parts cleared customs on Monday and were at the dealers on Tuesday.
New Haldex and associated parts installed and they went to test drive but the diff was still locked after all of the electrickery and mechanical fittings were plugged in, a faulty solenoid was found and replaced !!!! (remember the electrical issues recently after the rhs door recall sealing let water in and damaged the central management thingy?

As the service receptionist was reading out the report I said "ah so a faulty solenoid has activated the diff?" ..............she went a bit silent and moved on swiftly to get me into my van !


Thoughts ?

Thoughts? OK......
You, @Loz and I all thought diff lock engaged, (and two of us hadn't even seen the van!)
I think the technician doesn't understand how the 4motion and differential lock works.
But I'm glad you've got it sorted and it's saved you having a Haldex service for a while!