[Dippy]

I just checked the drawings. In 2011 the box had two filters, 8K0317823 "oil pressure line & filter" and 0B5325060 "filter", whereas in 2012 (and on) it only has the 0B5325060 "filter". This initially seems contrary to the evidence, that the earlier boxes with 2 filters don't have any service recommendation to change one of them, whilst the later boxes with only one filter do. However if you think about it, Audi engineers decided to redesign the s-tronic oil system and decided that they could delete the filter in the pressure line. Possibly they decided that if they did this, and effectively filtration is reduced (the other filter did not change), then the remaining filter would need to be periodically changed. I don't know if this is the answer you are looking for but it makes sense to me.

Notwithstanding that, your concern is still valid. Many of us do decide to change parts outside Audi's service recommendation in the interests of the health and reliability of our cars. However getting a franchise Audi dealer to service early is easy, but getting them to change an officially non-changeable part can be difficult. Indeed it can be difficult to get a franchise Audi dealer to provide a part that does not officially exist for a certain model - such as a dipstick! If necessary you might need to go to an independent Audi service company. They are usually happy and even eager to provide a level of servicing which is sensible for an enthusiast to request, and to which a franchise Audi dealer has replied "computer says no".

 

[Dippy]

The filter shown on the first page of the first pdf is the 8K0317823 "oil pressure line & filter", and as it states, it is only replaced if the gearbox is as well. The other filter shown is on all engines including 2010 and before, so as I suggested, it was not non-replaceable, just that replacement was not recommended.

 

[Dippy]

You could be right Adrian. However I'd have thought that in that case they would just have two drawings, one showing only the in-line filter and the other showing only the cartridge filter. It seems strange to have a drawing which shows both.

 

[Dippy]

The first version of the DL501 had two filters, and neither was a service item (i.e. officially). But even when Audi launched this version they planned to delete one. They did so in the next version in 2011-ish, and at that time decided that the remaining filter would now be a service item.

It is well know that most Audi franchise dealers will follow the "is it an official service item" rule and so it can be difficult to impossible to persuade them to change a non-service item. This is where the independents come in.

Remember that there are many factors why Audi will declare an item to be non-service or lifetime, and reliability is only one. Best make your own decision if you think any component should be renewed, but as I stated you might need to go to an independent to get it done.

Also worth noting that a tuned car automatically breaks the rules on which the service advice was based. So that means reducing the time between services, and removing some items from the non-service/lifetime list. So for example the DL501 s-tronic 'box has two oil systems. The ATF oil is a service "item" but the hypoid oil is not. A tuned car should have the AFT oil changed more frequently than the official schedule, but also the hypoid oil should be added (but exactly when is moot).

 

[Dippy]

I think you'll struggle to find a single preferred failure mode for the DL501, however it would appear that there have been reports of problems from owners who have either admitted missing the scheduled (ATF) oil service or had bought a used car which has missed it.

On the B8 S5 there is no requirement by Audi for the hypoid/gear oil to be changed, ever. But it does seem strange that the requirement for the B8 RS5 is for it to be changed every 19K miles. Similarly why does the sports diff need both ATF and hypoid/gear oil changed every 38K miles on an RS5, but not on an S5 (where in fact those oils never need to be changed).

This is why we enthusiasts should make our own decision on what needs to be serviced and when. My car is coming up to 3 years old - it has only done about 12K miles but has been stage 2 for the last 4K of those. I'm currently deciding what needs doing at its next service, and it will definitely include the DL501 ATF oil & filter. I doubt that I will get the gear oil done this time, but it will be done at some point in the future. Since I do so few miles I'll be basing it on years and so I'll probably choose either 5 or 6 years old to have both oils changed on both my DL501 and sports diff (assuming that I will be keeping the car).