Ook, it seema that topic needs some hands on..
So each gearbox has a 3digit specific key after gearbox name.
E.g.
MQ350 M6F QEY - manual 6 gear FWD (in my case Superb mk3 2016 2.0 tdi 140kw)
MQ350 M6A QGN - manual 6 gear AWD (case of Superb mk3 2016 2.0 tdi 110kw 4x4)
..and so on each combination MQ200 MQ250 DQ*** etc..
On each car there's a sticker rear area for reserve wheel/storage box, some times if not there (for cars after 2021) it is on the service book when paper or online. PR-Number plate
Big POINT(!) Manual gearbox:
- initially for MQ200 MQ250 was no service recommended at all life time
- same applied for MQ350, but even so common mechanics recommend change at 100.000km, then later started a recommendation of 60.000-80.000km or 5 years. Something happen(?) still question mark.
Maybe because, brake fluid, Stop What?
Because it has service for 60.000km, and too less mechanics knows(out of Official Dealer and Bosch Service Centre) that when purging brake oil out with new one, has to respect the norm, plus the sequence for clutch cylinder for manual gearbox and for DSG together with brake cylinders because it use same hydraulic system
- after which OBD and ABS adaptation with brake and clutch
But what happen?
2015 - 2018 cars with MQ350 from factory received GL 4+ Castrol transmax V 75W80 (!)
In 2019 they moved officially to Shell, and most cars get 75W90, and here when people get to idea let replace gearbox oil they put 75W90 instead 75W80 for cars before 2019. Some get bag gear synchronization 2 to 3.other 5 to 6 etc..
So if you get the gearbox with wrong oil, e.g GL5 instead of GL4+ it seems not big deal but is huge risk to get Oxydation on it due to different metal reaction.
So is better to get correct original oil without any kind of extra additives unless you lost hours and days studying what and why you need and take the risk.
Now some brands names 75W only that's strange as old school they assumed only one type of oil is it 75w80 or 75w90 no body knows ... But Castrol say 75W80
So make sure to identify if the gearbox needs 75W80 then that one must be and nothing else. As said mostly 2015 till 2018 and some mid 2019 depends when car sells..
If gearbox datasheet says 75W90 then that one is, in fact it wont say 75w90 or 80 but it will have a VW part number which can be searched. This mostly after 2019.. depends when build and gearbox Key index.
Then next: gearbox differential (front) will take 75W90.
As well as Rear Differential when 4x4 AWD will take 75W90
Plus Haldex takes special liquid.
So now we know there's cars taking service for manual gearbox with 3 different oils for transmission and others with 2, others with 1 type.
When dsg same apply, dsg + 75w90 differentials+ haldex if 4x4.
Here specific case combination: kind of 4 oil drain plugs but 3 oil type
Gearbox Mq350 m6a 4x4 02q-qgn
- 2.15 - 2.3l, 75w80 (castrol transmax manual v - no alternatives if you want car shifting as car not as tractor)
- API GL-4+
- vw *G 052 527 A2*
- VW G 052 171
- VW G 052 527
- VW G 052 512
- VW G 052 532
- VW G 055 512
- VW G 055 532
+
Front differential
- 0.9l, 75w90 (original castrol transmax axle long life then Shell both are VW - alternative Ravenol LiquiMoly, Motul, search reviews FOR your car all are unique or believe in economy a bit and pick the one more accessible)
- VW G 052 145 A2
- VW G 052 539 A2
- VW G 052 911 A2
<=>
Rear differential
- 0.93l, 75w90
- VW G 052 145 A2
- VW G 052 539 A2
- VW G 052 911 A2
+
Haldex
- 0.66 - 0.74 l, special (suggest VW only or top brands again .. as Castrol doesn't sell it to public as it is VW till 2018, then VW is Shell, public sells has Ravenol and guess LiquiMoly)
- VW G 052 175 A2
- VW G 055 175 A2
- VW G 060 175 A2
Now let's assume you've followed correct procedure for the oils change with all bolts seal rings cleaning and proper Nm torque all set:
- next elevate the 4wheels and slowly run all gears and 4x4 for a while , confirm no cracks etc.. there can't be any, but it will be some with gearbox selecting and haldex pushes
- next perform haldex adaptation using proper OBD diagnose
- next do adapt manual gearbox selector (fix gearbox service mode under air filter intake, then remove selector springs, then push selector.inside.the car in service mode and hold with 6mm hex, back to gearbox springs push them both on place, back inside remove 6mm holder and leave N, now releas gearbox from service mode outside, attach air intake and test drive) you should have smooth shifting as from factory and when in N there should be no bounce moving, but firmly in the middle.
4x4- extra adaptation for haldex via OBD
Dsg- extra adaptation via OBD
And extra tipp:
MQ350 doesn't love much bad shifting, that means in order shift up while driving you must push RPM bit higher to allow properly be engaged and smooth
Now ehen shifting down, if you shift down normally lower speed without braking then shift it down, if you hit the brake then wait for RPM go lower 1300, now press clutch and disengage.
(!) If you need to brake extremely hard, emergency brake etc, hit down both pedals together clutch + brake, stop down only then move shift selector to N or else if you continue driving.
Believe or not, mine Superb 2016 is 350.000km and shifts as new, 2nd owner from 163.000km .. mq350 02q-qey fwd 2.0 tdi 140kw.. it has the issue with shifting 2to3 and I was able to solve that as ler the guideline.
Attention (!)
- changing wheel size out of default factory may need proper adaptation to the wheel circumference for speed proper indicator
- installing wheel spacers, lower springs also affects all this need adaptation after