Full S-Tronic and rear sport differential service (RS5)

Great write up @Ape_Factory,
Definitely using this for upcoming service :+1:

I have a question for you guys, is the intervals for service really critical ?

I don’t track my RS5, but drive it hard on Dubai beautiful roads :heart_eyes:

Would changing all fluids every 50k be just fine ? Engine every 10k ?
Or I do really have to stick to different intervals for each fluid ?

Welcome and thank you a_ibrahem! I know a few other RS5 owners in Dubai!

On the service intervals, I’d stick with the Audi factory recommendations, especially for the transmission and rear differential. They seem to be the problem children so to speak. Do not go longer on the rear diff OR the MTF side of the gearbox. We rev out pretty high and I’m sure there’s a lot of oil molecule shearing taking place.

On engine oil, I actually recommend every 5,000 miles (8,000 Km) as it’ll help with longevity and reduce the amount of volatiles (off gassing) being ingested by the engine through the PCV system. It also gets pretty hot there so I’m sure that’ll have an effect on fluid longevity.

On another note, the JHM stage 2 tune will help reduce engine temps and I also have a transmission cooler which is extremely effective. The two other RS5’s I know in Dubai both have the trans cooler. Just shoot me an email, redmistracingllc@icloud.com or sales@redmistracing and I can fill you in.

What Ape said. Audi’s intervals are too long already. They only care to get it through the warranty, if you want it to last you need to change them earlier for the long run.

Thank you guys for quick and informative response,
Will get in touch with you @Ape_Factory, good to hear there is more RS5 here, don’t see it much tbh

My aim here is not to save or delay the service, I’m just trying to fix an easy to remember pattern for the service,

I do all my other cars this way, all fluids replaced every 50k and been fine, but I have to admit RS5 is most complicated in all

I understand that MTF in gearbox only need to be done every 20k miles, ATF and differential bother at 40k miles ?

So 50k km will be shorter than recommend intervals except for MTF in gearbox

Engine I’m doing every 10k km I understand it’s recommend every 15k km

So if MTF can’t handle additional 20k will have to stick to Audi recommendations then.

Hello again :slight_smile:

in process of ordering everything for the service, I noticed that same oil Motul Gear 300 is used for the MTF in gearbox for 30k interval and also for MTF in rear differential for 60k interval

is that correct or i misunderstood something ?

@Ape_Factory @hahnmgh63

appreciate your inputs

You are correct. Every 40,000 (60,000 Km) for the rear diff (both the ATF and MTF side) and the MTF in the transmission every 20,000 miles (30,000Km).

Can it hurt to do the rear diff more often? Nope.

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Hi @Ape_Factory. I’m a new owner of 2014 RS5 convertible in Ontario Canada. Nice & clean with just under 40,000 miles right at the moment. I have read through most of your articles & watched many of your how-to videos & really appreciate the time & effort you have put into them. Thank you. Based on your recommendations & thanks to your detailed instructions I’ve already bought/used VCDS & installed RSNav, among other things. All good! My only slight regret in not finding your online resources sooner is that I would have bought the JHM exhaust instead of the Capristo & used the $$ that I would have saved on something else. Oh well.

My next area of focus is to change the fluids/filters in the DSG & diff. I’ve ordered all the fluids & materials from ECS but won’t have them for a couple weeks since they have to clear customs to get here. In the meantime, I had a quick question for you: how much do you think the age of the fluids matter, based on your experience? According to the service records from the Audi dealer, my DSG has 4,100 miles on the MTF & 17,400 miles on the ATF. The diff has 17,400 miles on both its fluids as well. While these are all considerably lower than recommended, the fluids with 17,400 miles on them have been in there almost 4 years (while the MTF in the DSG was changed only 18 months ago).

So my question is how urgently would you change the fluids in the DSG & diff if you were faced with the same circumstances as me? I am “between garages” right now so I have to decide if I should borrow a garage ASAP or wait until I have my own sometime in September/October. The OEM maintenance manual specifies that the DSG & diff fluids be changed based on mileage but mentions nothing about how many years (unlike other items such as spark plugs, which specifies 55,000 miles OR 6 years). Even the maintenance schedule in the link you posted above mentions nothing about the number of years when it comes to DSG & diff fluid, so maybe these fluids only degrade based on miles driven & time doesn’t much matter.

Thanks for your help!

Just to be safe, I’d change them.

Audi’s recommendations are based on mileage as well as time for most items. Their main service intervals list time as well as mileage but they don’t necessarily specify that for each individual fluid. Fluids can degrade over time due to condensation/water contamination and outgassing. Just how bad do any of the transmission fluids get over a period of sitting stagnant for years? Dunno honestly, you’d have to send them out for testing. But it’s relatively inexpensive insurance to swap them out vs. developing an issue to fluids which are out of specification. Plus you’ll know they’ve been done and hopefully done correctly.

Short version, you can’t hurt anything by swapping the fluids out. The MTF side of the transmission is sealed, the ATF side does have a vent. On the rear diff, it’s sealed as well but you’re already at 17K miles on those fluids plus time.

The rear differential is fairly easy to change. I’d say, at the very least, change that but the other stuff can wait until fall. If your car is shifting erratically or what you deem to be “not normal” then I’d consider changing the fluid sooner than later. If you’re planning on doing track days, I’d definitely change the fluid all around.

Fantastic, thank you for your feedback.

The transmission is shifting fine & I have no plans for any track days, so there’s no particular urgency to change the fluids on that front. However, I’ll still make a point of borrowing a friend’s garage for a day & changing all the fluids, based on your recommendation. And thanks to your detailed instructions, I have a list of all the tools & materials that I will need to do the job! As you can imagine, part of the hesitation to do this kind of work in someone else’s garage is not having all your own tools there so I’m really grateful for all the work you put into making these instructions & putting them online.

Take it easy!

Most welcome and sorry for such a late reply! I’d typed all that out a while ago and then forgot to hit the “reply” button! The forum saves your posts so when I logged back in, I saw I hadn’t actually responded. So my apologies.

It’s all good. I didn’t get the stuff from ECS until yesterday anyway. Plus I’m hardly in a position to complain about getting experienced advice for free. Furthermore, a fellow Audi/VW enthusiast friend has offered me his help & garage for July 10th so I wasn’t in a position to do it earlier than that. It turns out he actually wants to go through the process with me on the RS5 & then get my help to do the Haldex service on his Golf R if we have time that afternoon. After that we might undertake the same DSG & differential service on his C8 Allroad at some point. So it all seems to be coming together very well!

Otherwise once I’m caught up on the overdue maintenance items (which are only overdue in terms of time rather than mileage), I will get back in touch with you regarding other upgrades. I have no plans to take the car to the track, but I’m intrigued by the JHM tune (although a little intimidated at the thought of installing it). Plus I’ll be getting a set of the standard JHM rotors at some point, which I suspect will be just fine for street use assuming they are similar or better than the OEM wave rotors. Since the car has been parked for 4-5 months every winter my wave rotors are getting a little pitted. One way or another I would like to contribute to your efforts!

On the JHM tune (installation), don’t be afraid of that. Assuming you saw my video on the tune installation process? I actually make myself available before, during and after the flash if necessary and I walk you through the entire procedure. Just shoot me an email, sales@redmistracing.com for best pricing. It’ll completely transform the car. Really does wonders. Pair it with the RMR transmission cooler and heat soak is pretty much eliminated and reliability is improved.

It’ll be a LOT to do the transmission/diff service and th en his Golf R in one day. Does he have a lift? That’ll make it easier. I really, really like the measure methodology, measuring the old fluid, adding a tiny bit for spillage, and using same amount to re-fill. If you use common sense, it makes it very easy to get the refill level right without the tedious process of checking it per the factory method. It’s worked for me time and time again.

JHM’s rotors are the best value out there, are more than capable of doing track days and are far better than OEM rotors. Since they’re semi-floating, they can account for radial expansion and if/when the rotors wear out, just replace the outer rings and save $$$!

Wow thank you for all the info. I will send you an email so we’re not making this thread unnecessarily long.

Adding to this as my as my gearbox MTF ie gear oil change is coming due I really wonder if 3k km intervals under normal use and no tune is not unnecessarily short. The S5, S7 are running the DL501 with compressor and turbos respectively and have no MTF gear oil change same as for thr OBC rear diff. For drivers doing most kms on the highway might just be waste. Similar to why we should change air filter every 3k km. Any thoughts on this? everyone welcome

The gearbox oil is changed every 20K miles (imperial). Not sure if that was a typo (3K Km would be far, far too short!) and you meant 32,000 Km?

I’m part of a Facebook DL501 message group which is almost entirely composed of S6’s having issues with their transmissions, albeit mostly with the mechatronic side but not always. Having spent some time in this group, I can say I will never own an S6 as the problems they 're having, and frequency, is truly staggering.

Then again, they don’t have the option of a turn-key bolt-on transmission cooler like the RS5, S4 and S5 guys do :slight_smile:

What you could do is capture some of the old oil next MTF change and send it out for analysis. That would give you a clearer picture.

Just remember, our cars turn another 2,000 rpm higher at redline than the S6 and I’m sure that has some effect.

One explanation could be the crown center differential, if it really is true that it was only ever used on the B8(.5) RS5/4 and no other models. Some USP if that is true, although it was used to sell some other models around the same time.