VAQ front diff service - how important?

[jr795]

I've been looking at a few approved used Cupras recently. Unfortunately it seems that main dealers, not used to servicing Cupras, often overlook the VAQ front diff service which is meant to be every 3 years.

Problem is on the 300 (the model I'm after) that means that as they are at newest a 2018, if the VAQ hasn't been serviced then it's now doubled it's interval at 6 years. How important is the VAQ service? Should I be concerned about this or is it nothing to really worry about? What's the worst case if the service was neglected, diff failure?

Edit: am I correct in saying that this interval is for the friction fluid in the pump, not the differential oil itself (which is meant to be 'lifetime')?

Thanks

 

[H Rafiq]

My Leon Cupra 280 had its first diff service at 104.5k for £109 at Seat. I couldn’t tell any difference in the drive of the car before or after the service. VAG claim it’s a ‘lifetime’ fluid, but it should be done every 3 years I believe.

https://www.reddit.com/r/seat/comments/16v6zrm

Guide to Front VAQ E Diff Lock LSD on Golf GTi, Autobahn, Seat Leon, Skoda Octavia – Vorderachsquersperre – Haldex Parts and ECU Repairs by Auto Fault Finder Ltd

www.haldexrepairs.co.uk

 

[jr795]

My Leon Cupra 280 had its first diff service at 104.5k for £109 at Seat. I couldn’t tell any difference in the drive of the car before or after the service. VAG claim it’s a ‘lifetime’ fluid, but it should be done every 3 years I believe.

https://www.reddit.com/r/seat/comments/16v6zrm

Guide to Front VAQ E Diff Lock LSD on Golf GTi, Autobahn, Seat Leon, Skoda Octavia – Vorderachsquersperre – Haldex Parts and ECU Repairs by Auto Fault Finder Ltd

www.haldexrepairs.co.uk

Thanks for the info, good to know it's not a huge problem. I guess even if the pump fails it won't brick the car, just need a new pump and no locking diff until it's changed

 

[RUM4MO]

Yes, exactly, one thing to know if you are thinking about doing this fluid change etc yourself, is, the VW Group branded version of this BorgWarner fluid, makes it clear that it should only be opened and used within 3 years of the manufacture date - which is printed on the containers of fluid, 0.87ltr if I remember correctly. Also VW, SEAT and Skoda recommend that it is replaced every 3 years - according to their official workshop manuals sourced via Erwin.

One typical thing is, I was in my local Audi dealership for some spares for my car which were "Audi specific", and I asked the price of the drain and fill plugs for the VAQ - and got no where, on reflection, probably there are no Audi models that have this VAQ on the front diff - my error, anyway, the parts guy told me that none of the Haldex systems need their fluid changed ever, and he "reinforced" this idea by saying that the fluid alone costs £57 - as usual not quite true!

I replaced the fluid in my older daughter's 2019 Leon Cupra at less than 20K miles and at 4.5 years. I bought and used one of these Laser Tools 6042, discharge syringe, which might even be now listed as EOL item which means that they are even cheaper than they were when I bought my one for that job. I keep meaning to find out the actual price of these drain and fill plugs from my local Skoda dealership parts dept as they are very easy for me to reach and park at, but I keep forgetting as I intend to remove the pump along with the fluid again this summer, mainly due to a mess up with my first fluid order being lost by Evri for maybe 3 months I got my money back and ordered in another container of fluid - and as I said near the start of this posting, this fluid does have a shortish shelf life.

 

[RUM4MO]

Actually very poor/bad timing on suggesting that you buy one of these Laser Tools 6042 syringes, from checking on the Laser Tools website, I see that that tool has been dropped and that their close/main outlets seem to have sold out of these as EOL items, which means it is only the regular ebay resellers that are still selling on their own stock at higher prices! Laser Tools have launched a replacement which has a longer output pipe length, I just bought a replacement length of pipe for my 6042 before using it as I had worked out that I needed it.

 

[jr795]

Yes, exactly, one thing to know if you are thinking about doing this fluid change etc yourself, is, the VW Group branded version of this BorgWarner fluid, makes it clear that it should only be opened and used within 3 years of the manufacture date - which is printed on the containers of fluid, 0.87ltr if I remember correctly. Also VW, SEAT and Skoda recommend that it is replaced every 3 years - according to their official workshop manuals sourced via Erwin.

One typical thing is, I was in my local Audi dealership for some spares for my car which were "Audi specific", and I asked the price of the drain and fill plugs for the VAQ - and got no where, on reflection, probably there are no Audi models that have this VAQ on the front diff - my error, anyway, the parts guy told me that none of the Haldex systems need their fluid changed ever, and he "reinforced" this idea by saying that the fluid alone costs £57 - as usual not quite true!

I replaced the fluid in my older daughter's 2019 Leon Cupra at less than 20K miles and at 4.5 years. I bought and used one of these Laser Tools 6042, discharge syringe, which might even be now listed as EOL item which means that they are even cheaper than they were when I bought my one for that job. I keep meaning to find out the actual price of these drain and fill plugs from my local Skoda dealership parts dept as they are very easy for me to reach and park at, but I keep forgetting as I intend to remove the pump along with the fluid again this summer, mainly due to a mess up with my first fluid order being lost by Evri for maybe 3 months I got my money back and ordered in another container of fluid - and as I said near the start of this posting, this fluid does have a shortish shelf life.

Thanks, seemingly dealers are happy to change it before sale if you mention it to them so I think as long as I seek out a lower mileage car say sub 40k and get it done then it should hopefully be fine. Especially if the audi dealer parts guy thinks it never needs changing in any haldex lol

 

[RUM4MO]

Remember non Cupra SEAT dealerships don't tend to carry out this part of the service, mainly as they don't have the consumables or kit or training to do this simple job. That is what happened to my older daughter when her car went to just a SEAT basic dealership's workshop for her year 3 service, they did comment or note that that work was due though.

 

[jr795]

Yeah i have heard that that is the case, unfortunately it seems most cars have not had it done. Would you say it's a huge issue if it's been missed or just something to stick to under my ownership?

To be fair from what I've heard people say the front diff doesn't work very hard anyway unless you're driving like your hair is on fire full time so seemingly it's not a huge thing if it's been overlooked?

 

[Damo H]

If my understanding of the bits are right, not changing the oil will potentially put extra strain on the pump, however not heard of these things failing. Clutches on tuned manuals and leaky thermostat/water pumps however....

Also main dealers likely change the oil and do not do much else. I'd recommend a decent independent to do it and get them to take photos of the filter before and after (decent ones do anyway). A proper clean of the filter is needed to make any actual difference.

 

[jr795]

If my understanding of the bits are right, not changing the oil will potentially put extra strain on the pump, however not heard of these things failing. Clutches on tuned manuals and leaky thermostat/water pumps however....

Also main dealers likely change the oil and do not do much else. I'd recommend a decent independent to do it and get them to take photos of the filter before and after (decent ones do anyway). A proper clean of the filter is needed to make any actual difference.

Thanks for the info, yeah ideally I would like an indy to do it as a main dealer won't do the filter but I can likely get the dealer to do it for free when buying whereas an indy would charge a few quid. Maybe I can get the dealer to change the fluid then pay the indy to clean out the filter but I'm not sure how much cheaper that would be anyway to be fair.

Yeah I've heard about the thermostat housing, will definitely be on the lookout for that. silica gel in the header tank is another thing I'd be looking to sort out straight away

 

[RUM4MO]

From what I've read, and on thinking about it, it makes sense, is, the debris from the multi clutch friction plates is mainly only released into the Haldex fluid while the diff "lock" is "inactive", when the diff lock is active, the multi friction plates will be getting locked solid by the increased fluid pump pressure. So if all that is true, which in my mind does seem logical, the rate of clutch plate frictional debris being deposited on the Haldex fluid pump's input screen will be greatest when the car is being driven "sensibly".

If you dig deep, there are some very nasty looking pictures of Haldex VAQ fluid pump screens as removed from cars at service time. One very annoying at least for me thing is, the sump of this VAQ system has quite a thin, but adequate skin thickness, so when it was being designed, to ensure that there was sufficient material for the drain plug to fix into, the area around that drain plug was made to be maybe 15mm thicker(a guess) than the surrounding sump inner surface, the result being that when you drop the old fluid out via the drain plug, the last 15mm or so of fluid remains in the sump - and that is where any remaining clutch friction debris that has dropped out of suspension in the oil remains, to get re-combined with the new fluid when the car is back in service - in my world, a bit annoying!

 

[tracktoy]

For my information is there a difference between the FWD and AWD setup, Like many I have seen lots and lots of horror stories on the AWD cars but not on the FWD ones.

 

[Damo H]

Thanks for the info, yeah ideally I would like an indy to do it as a main dealer won't do the filter but I can likely get the dealer to do it for free when buying whereas an indy would charge a few quid. Maybe I can get the dealer to change the fluid then pay the indy to clean out the filter but I'm not sure how much cheaper that would be anyway to be fair.

Yeah I've heard about the thermostat housing, will definitely be on the lookout for that. silica gel in the header tank is another thing I'd be looking to sort out straight away

They need to empty it to clean the filter, so won't make any difference I'm afraid.

 

[Damo H]

For my information is there a difference between the FWD and AWD setup, Like many I have seen lots and lots of horror stories on the AWD cars but not on the FWD ones.

There is a similar pump filter that need cleaning on the VAQ vs Haldex (think I've remembered that terminology correctly). The VAQ just takes advantage of the hole in the gearbox that is freed up for the rear prop etc to be able to do its thing with the FWD Diff.

 

[jr795]

From what I've read, and on thinking about it, it makes sense, is, the debris from the multi clutch friction plates is mainly only released into the Haldex fluid while the diff "lock" is "inactive", when the diff lock is active, the multi friction plates will be getting locked solid by the increased fluid pump pressure. So if all that is true, which in my mind does seem logical, the rate of clutch plate frictional debris being deposited on the Haldex fluid pump's input screen will be greatest when the car is being driven "sensibly".

I think it's six and half a dozen really. While that would make sense, in order for any debris to be created in the first place the friction plates would have to 'lock', which doesn't happen under normal driving conditions, only if one wheel loses traction. So if you are driving sensibly the friction plates wont wear at all (theoretically)

 

[SuperV8]

I think it's six and half a dozen really. While that would make sense, in order for any debris to be created in the first place the friction plates would have to 'lock', which doesn't happen under normal driving conditions, only if one wheel loses traction. So if you are driving sensibly the friction plates wont wear at all (theoretically)

They would seldom 100% fully lock.
These wet plate clutch packs would most likely/most often be varying the torque i.e. slipping, when accelerating from a standstill.
A car which has clocked up high miles sat on the motorway will have very little wear of these clutch plates - as these clutches will not be operating at motorway speeds.
A car which has been 'enthusiastically' driven around town which has a lower accumulated mileage - could have much more clutch pack wear.

As ever - buy condition, rather than just a low mileage.

 

[RUM4MO]

Yes, @SuperV8, that sounds like a more logical way of considering this, pulsed Lock/Unlock would indeed be where the bits of friction plates ended up in the fluid. Maybe I should have thought more about what I had in the past instead of just accepting it.