About MTF temp I guess this would trigger a fault code we can read with VCDS:
Correct, it would trigger a code. The ATF side heats up much more quickly, and to a higher level, than the MTF side. Normal driving, the two sides are very close in temp so there’s some sort of heat exchange happening between the two sides.
Hi @Ape_Factory
I’m about to service my 0B5 S-Tronic on an S5 B8.5, I’m quite clear on the steps involved in doing the ATF side and I just had a few questions with regard to the procedure for the MTF side
Blockquote
MTF Side
Drain plug torque specification is 45Nm
Fill Plug torque specification is 45Nm
My drain plug doubled as a temperature sensor and was depicted wrong in any of the workshop manuals. Comes off easily and very accessible but it is a 26mm socket (short is fine) so make sure you have one of those before starting.
-Make sure the new gear oil is at about 68 degrees F, room temperature
-Slide the used oil collection unit underneath the gearbox drain which is located just aft of the ATF pan.
-Place a cloth over the tunnel cross member to keep oil from getting into the cast pockets when the fill/inspection plug is removed.
-Remove the transmission fluid level inspection plug first. Fluid may come out of the inspection port so be prepared.
-Remove the transmission drain plug and drain the fluid into a container.
-Install a new transmission drain plug and torque to specification or reinstall the temperature sensor.
-Fill with new transmission fluid until it begins to run out of the hole and let it sit for at least 15 minutes so the fluid settles internally.
-From then, add 50ml every 15 seconds until the transmission is full. The MTF must be up to the lower edge of the check/fill hole.
-Tighten the fill plug to specification (45Nm)
After filling MTF up to the lower edge of the fill hole, would it be a good idea to turn on the car and shift through the gear modes, and check/fill in more oil if level goes down?
Or is what you are suggesting, to wait 15 min for oil to settle and check level will suffice?
Is there any need to bleed the MTF side by running the engine with the fill hole open (while adjusting oil level?)
Ideally I would like to follow the procedure used by Audi technicians, unsure if anyone has access to the Audi workshop manual pertaining to the 0B5 service.
I’ve also been curious about why you mentioned making sure that the oil is at room temperature. In which situation oil wouldn’t be at room temperature? And in such situation, what would realistically happen if you filled with oil that is above/below room temperature? Just trying to understand the reasoning behind this recommendation.
My OEM MTF oil is sitting in my garage and it does get hotter than 68 degrees late afternoon. Should I store my oil inside my house maybe?
Thank you
Hey there, out of town on vacation so going to answer this somewhat quickly otherwise I’ll forget!
You’re fine letting it settle for 15 minutes. Factory service manual specifies this method. I followed the FSM. I can get you a copy, just send me an email, sales@redmistracing.com and I can send you a link to download it from my google doc folder.
On temp, oil will expand/contract depending on ambient temperatures. So fill as close t0 70-75 degrees. If you’re filling in the middle of winter, and it’ s cold in the garage, it can throw off the measurement. Same if it’s hot. The metal inside the transmission expands enough to affect how much oil can be added before it begins to dribble out the fill hole.
In your situation, you’ll be just fine 
-Michel
Exactly what Ape said. I have a '13 S5 & a '13 RS5. The S5 just has a regular drain plug (replaced mine with an ECS Magnetic drain plug). The RS5 has the temp sensor in the drain plug, so that is a difference. Filters and filling procedures for the two are identical.
Thanks for the reply and the insights.
I’d love a copy of the FSM if it’s not too much trouble. I’ll send you an email.
And now I understand better why the temperature-related recommendations, I didn’t know oil expands/contracts on ambient temperatures, super interesting!
Thanks and enjoy your vacation, I have everything I need to get started now
Anyone see a problem with doing the transmission service on a 4 post lift and removing the subframe brace while the wheels are down? I would not have thought twice about this but it was mentioned in a youtube vid.
At 6:06
Thanks!
I do it on a 4 post lift. I use a tall transmission jack under the rear of the transmission/center Diff to support the back before I pull the transmission subframe.
Hey all, I’ve completed my first ATF, MTF, and Standard Rear Diff oil change.
Big thanks to @Ape_Factory for the detailed write up, definitely help having a clear picture of the process.
Interesting things to note:
- On the S5, no temp sensor on the MTF drain plug, which means that on the S5 I didn’t have that cutout on the cross brace like on the RS5 which made getting to the drain plug a bit trickier.
For context here’s the RS5 MTF drain plug (Ape’s picture)
(https)://i.imgur.com/vDO89Ty.png
And here’s how it looked like on my car, note how there is not cutout on the cross brace
(https)://i.imgur.com/RKmhh2t.png
Couldn’t get to the MTF drain plug with a ratchet/socket. Even an insert bit into a ratcheting wrench wouldn’t fit. Had to slide the insert bit in with my hand then use the open end of a wrench from the side to crack it open. For a moment I thought I was going to have to take off the whole cross brace
(https)://i.imgur.com/O4QTMnx.png
(https)://i.imgur.com/x5I5VlP.png
- When I removed old internal ATF filter, the seal normally located on the filter nozle stayed stuck in the hole inside the ATF where the filter nozzle goes. Also, the shop that did my ATF last time used a cheap Vaico filter and they didn’t add the small seal on the cross pin. I was quite annoyed and one of the reasons why I hate taking my car to a shop, you never know what they use/do. I’m glad I can fully service my own car now.
(https)://i.imgur.com/RlnkVnL.png
- The nozzle seal fished out from the ATF. It looks “melted” as the grooves are not as pronounced as on the new filter. Is it normal or due to poor quality material?
(https)://i.imgur.com/BTFPBva.png
- External filter condition
(https)://i.imgur.com/tr4iHKS.png
- Oil condition. MTF is darker than ATF. I really don’t get why AUDI doesn’t recommend to replace MTF for the S5.
All in all, it went pretty smoothly and it’s largely due to Ape’s great write up which allowed me to be prepared with all the tools needed. Didn’t make a big mess considering the job, the fluid pump that directly screws onto the oil bottle was such a great tip and made filling oil a whole lot easier.
PS: Why does this forum have so many limitations to post? No more than 2 attachments, then no more than 2 links, no more than 2 posts in the same tread for new users so I had to delete my previous post. Quiet discouraging to post/contribute
1 Like
Unfortunately I don’t control the actual forum rules so apologies on that. I think it’s to prevent spam but that’s what us mods are for!
And glad my writeup helped. Very interesting on the differences between the S5 and RS5. And I agree, all the DL501’s should have the same change intervals, especially if you’re modded and making significantly more hp. I do thin the high rpm running of the RS5 drivetrain necessitates the more frequent changes. More heat, more shear.
If those are clean containers, I’d look at having the MTF tested just to see what sort of shape it was in.
I do make a transmission cooler for the S4 and S5. You may want to consider it.
1 Like
Figured out how to change your status, you are now a regular member
1 Like
Lovely thanks for that
I actually wanted to follow up on that transmission cooler you mentioned above. Can you link me to a product description/picture and maybe how and where it is installed?
If it’s not too difficult to install I may consider it.
Otherwise been driving the car for 1+ week now since full S-Tronic service and I’ve noticed smoother gear shifts and it “fixed” the rough gear shift from P to R when the car is cold. It wasn’t the case before so it was definitely a sign that the transmission was due for a service. Like right around when the car reached 60k (Audi’s recommended interval to service S-Tronic), in the morning on the first start, when I shifted from P to R to reverse out of my garage, I’d have to apply a bit more force to shift to reverse as I could feel resistance in the gears. And it happened exactly around 60k, fascinating. I think servicing the S-tronic before it gets to that point would make sense.
I agree…I actually service both sides every single time instead of servicing MTF each time and ATF every other time. It’s more expensive but more peace of mind. At the very least, you can just swap fluids and keep the cost down.
On the transmission cooler, link here: https://redmistracing.com/ols/products/rmr-transmission-cooler-kit-for-the-audi-s4-and-s5-b8b85-30t-with-s-tronic-transmission
I make them for the S4/S5 and for the RS5. It can be installed at home in your driveway/garage with normal hand tools, really nothing special needed. I have installation instructions in PDF format and it also lists all the tools needed. It’s about a 3-4 hour job, nothing super hard, just little steps and some patience. Most of it is actually very easy.
I also have longer heat exchanger brackets that work for most HX brands but are really designed for Marc and PLM. Literally the same bracket just longer as the cross bar moves everything forward by about 5". So you now have room for a larger heat exchanger and the transmission cooler.
Here’s a video I did on the cooler. It’s RS5-specific but much of it applies to the S4/S5 as well.
It’s quite effective and I think it’s now been installed on around 300 cars all across the globe from here in N. America, Canada to Europe, Japan, Hong Kong, India and S. America. It’s 100% bolt on with no cutting and is fully reversible.
Besides that, I’m a dealer for JH Motorsports, 034, BC Forged, Ohlins, Antigravity batteries, Kline exhaust systems, etc…
1 Like
Beautiful, thanks for the reply and all the details.
I’ll have a look and review the video to see if it’s something I can do.
Thanks Ape, Audi should hire you to improve their engineering 
Hi folks, I’m doing this service on my 2014 today. Unfortunately, my driveway is (like most) not level and I don’t have a garage to do this in. Despite my best efforts, I cant get the transmission perfectly level, so I’m doing it the “measure and fill +50ml” method. Just to make sure I don’t have any big discrepancies when I do it this way, does anybody remember how much ATF and MTF transmission fluid you drained/put back in?
Read through my written description or watch my video, I think I mentioned how much I drained/ filled there somewhere :). I can’t remember off hand but it was def under 5L on the MTF side, 5-6L on the ATF side.
Appreciate the reply, Ape. I didn’t see it in there (just saw it for the diff), but that’s no big deal! Really more of a sanity check than anything. The transmission is close to level anyways, so I should be fine.
This car has had its fair share of German Engineering quirks as I’ve worked through various maintenance/repairs - learned the hard way to be better safe than sorry!
Besides all that though, was sad to hear that the RMR trans cooler is going to be discontinued! I totally get the reasoning though - hopefully sometime we can scrounge up a big enough group to make it worth it. I swear I’ve had that page bookmarked from 2 years ago, before I even bought this car.
All right folks, it happened. And it is not a good it.
As of right now, do not use the oil pan bolts that ECS tuning provides with their DSG service kit (PN ES#3551610).
Upon attempting to reinstall the ATF oil pan, going painstakingly slow in my little star pattern, I got back to the first bolt, and all of a sudden, righty tighty was righty loosey. The bolt broke, inside the bore, under the mating surface. it took… maybe 5 ftlb for it to break? No discernable torque increase, and then it was gone.
Digging deeper into this, here is what I found. The threaded holes drilled into the transmission have a drill point at the bottom, as most holes do. However these look to be 90° included angles, rather than the typical 118°. The OEM bolts also have this angle, seemingly to fit deeper into this hole. The ECS bolts do not have this angle, and are even slightly longer than the OEM bolts.
I then bottomed both of these bolts into the same hole, and it turns out, the ECS bolt bottoms out before clamping the pan and gasket. I measured, and its about .020" too “long”. Of course, that number would change depending on the tolerances of all the components included.
Email is out to ECS to check their stock/remove these bolts/use OEM ones.
Bolt Comparison and Installed Pictures
Me and a friend of mine spent something like 5 hours trying to get that thing out, to no avail. I then promptly went on vacation, and spent 5 days at the beach wondering how the hell I was going to get that little f*cker out.
I came back, spent another hour or two at it, once again, no luck. I’ve never properly drilled and installed a helicoil before (which i figured it would need), so embarrassing as it was, off it went, towed to the shop. They just finished with it today, and unfortunately, that bolt was stuck so bad and at such an angle that they had to size up the bolt AND still helicoil it AND charge me an arm and a leg for it. Hurt my soul to hear, but I’m glad that its fixed. Hopefully this doesn’t prevent dealerships from working on the transmission in the future if that’s what it comes down to, because of the mismatched sizes.
Anyways, long story short - check your bolts. Don’t end up like me. And good luck.
Too late for my opinion but for things like that I use this dealer and find their parts prices for many OEM parts are less than ECS, for non dealer stuff I usually use RM European, FCP, or Europaparts. I just ordered a set of these as I’m coming up on 25k since the last service on my S5 (Audi says 35k).
Not sure what ECS price is but I bet it’s more than $0.30 each.
Thanks for the recommendation there - I’ve had some trouble in the past as to where I should buy my parts from. I’d like to say I treat this car better than my daily, and not just buy the cheapest thing that pops up on google lol.
The kicker of all this is that I actually had a set of OEM bolts that I ordered from FCP euro, along with the crossmember stretch bolts and such. So I had two new sets, FCP euro and ECS. ECS was just closer to my hand, and they ended up being the ones I grabbed. Imagine if I had just grabbed the other bag of bolts… ahh, what could have been.
Not sure what the ECS price is, as it came with the DSG service kit, but I would tend to agree with you there.