I'd generally describe someone as reluctant when they question something four times - 'Doesn't Skoda say the diff is "lifetime"?', 'What's the evidence for this?', 'Who is the authority on this?' and 'I was under the impression that the dealers usually say it’s lifetime.' Since this isn't going to be let go, I've spent a good twenty minutes on Google. Something you need to understand is that VWAG, be it Audi, VW, SEAT, Cupra or Skoda, are utterly useless when it comes to service intervals and maintenance schedules. This is something you will find on every single VAG forum. While a phone call or quick search on here, SEATCupra.net or VWVortex.com would have given you the answer you needed, I'll explain it anyway. The reason you've been unable to find any reference to the VAQ LSD is because VAG don't call it that in any documentation. I don't know why, but they don't. VW refer to it as the 'front axle differential lock', while Skoda only refer to it in service items as the 'final drive oil'. This is a bit misleading, as 'final drive oil' is the same term used for Haldex AWD systems, which have a slightly different interval. I'm not going to send you a thirty-something email chain between my friendly Skoda dealer and I (not least because I'm not putting my buiild sheet and VIN on the internet), but that is what I found out. You can choose not to believe me if you want - I'm trying to help. The dealers are absolutely useless. For service departments filled with 'car enthusiasts', they are utterly woeful - I wouldn't go near one if they paid me. They do not understand the VAQ, and most don't even know it exists. As mentioned before, it is an electronically-controlled, hydraulically-actuated multi-plate clutch unit - it uses hydraulic pressure to enage and disengage a clutch that ties the front wheels together. This needs to be looked after properly. If you do find a dealer that knows what they're on about (I haven't yet) then most don't service it properly and won't clean the pump screen/gauze. The following is a section of email between a service advisor and I - 'Please note that the Diff gauze isn’t included in the cost for the Front Diff Lock Oil. As per SKODA’s Workshop Manual, when we perform this operation, only the Haldex Oil and Drain Plug are replaced. The Diff gauze would be an additional cost.' Clearly then, it wouldn't be a proper service according to the Skoda manual. Now, with all of that in mind, we can find a few official sources, outside of the internally-available service information. Again, remember that VAG service information is rubbish - hence why most sensible owners default to what is recommended by specialists. This document mentions 'Front axle differential lock: Change fluid (if equipped)' This document also mentions 'Front Axle Differential Lock if applicable: Every 3 years' This link, under the extended scope inspection, describes 'check/replenish final drive oil', with reference to this being every 3 years, or 30k miles. This graphic shows that the Haldex 4x4 wants doing every 3 years or 30k miles - remember that the VAQ is the exact same Gen5 pump as the AWD system. This document mentions 'Front Axle Differential Lock if applicable: Every 3 years' This service, under any vehicle equipped with a VAQ, also describes 'Front Axle Differential Lock (if equipped) - Change fluid every 3 years' Although not official, if you don't trust AwesomeGTI, you're wasting your time on any VAG forum - 'Every 20,000 miles Recommended Haldex oil + filter interval' and 'Gen 1, 2, 4, 5 and the VAQ front differential'. Link to here. I can't speak for the MQB Evo intervals, as I believe it was only Skoda that reduced the VAQ to 2 years. You question 'time versus mileage' - it is generally assumed that the average person covers 10,000 miles a year - therefore, a service interval of 30,000 miles becomes, according to VW too, 30k or 3 years, whichever is sooner. I've never heard of anyone being told the unit is sealed for life. Even if they are - two things. Firstly, this is likely the words of an inexperienced, bored service advisor - I wouldn't trust them as far as I could throw them. Second, some common sense is required. If we know that the Gen5 Haldex AWD unit needs servicing, then it stands to reason that the Gen5 Haldex VAQ unit also needs servicing. The reason that many places 'might suggest a more agressive service schedule than is... required' is simple - VWAG service information sucks, and the stuff breaks. You can imagine that if an electronically-controlled, hydraulically-actuated multi-plate clutch unit sounds liable to problems, then two seperate manual gearboxes, spliced into one electronically-controlled unit with two concentric input shafts and two clutches is even more liable. That's what a DSG box is. For completeness, and seeing as you mentioned it, we can touch on the DSG intervals. VAG uses several DSG types - the DQ200, DQ250, DQ381, DQ400e, DQ500 and the longitudinal DL501. All of these boxes are 'wet clutch', meaning the clutch plates are submerged in oil, with the exception of the DQ200 which is a 'dry clutch', where the clutch plates spin in air, like a traditional manual setup. All of the 'wet' boxes have filters that can, and should, be changed - even if VAG doesn't do this. The DQ200 has no filter, but does have both a gear oil and MCU (Mechatronic Unit) oil to change, when it is needed. This is often suggested around 100,000 miles. All of the DSG boxes have a recommended service interval of 40,000 miles, except the DQ200 (no interval) and the DQ381 (80,000 miles). This is because the DQ381 is supposed to use a more advanced low friction oil. Whether this actually works or not, I don't know of anyone that leaves it until 80k. I did mine at 40k, and plan to take another view at 60k - I don't cover the miles, but I do drive very hard, so am going off of 40k/4 years. I see you've requested to delete your account. It's a shame, but if you find the forum such hard work, then I don't suppose you will miss it. As you can hopefully see from the above reply, many of us here on Briskoda do have a wealth of knowledge about these cars. I find that, generally, people don't tend to take too kindly to their information being questioned multiple times. Were it new information, then I could understand, but this is a topic that has been discussed many times since 2017, and a simple search will show many links and screenshots by various members over the years. Personally, I found your replies to be a bit standoffish and cynical, although I appreciate this may not have been the intended tone. Oh, and in reply to this 'but all the sources I find are independent and have an interest in making money' - what do you think a main dealer makes more money from, selling cars, or servicing them? I'll let you in on a secret - it's not the first one. If you spend the time, have a search on the various VAG forums and see why stealers are hated so much - they are dishonest, unreliable, often incorrect, careless and vastly overpriced. Buy the car, be it brand-new or approved-used, and run. I hope this helps, whether you view this as a member or guest.