B8 S4 Complete DSG Maintenance Service & Sport Differential Service DIY

[Aiserock]

I might be wrong but I thought 8.5 didn't have the external filter

I have a 2014 and I did have the external filter. Funny too, because my kit only had the internal filter. I've yet to source the external filter outside of the dealership.

[s4sprint]

Anyone yet have any info on the front differential? Oil capacity, pics of drain/fill locations, any special issues?

[minman26]

Filters:
There are 2 different ATF filter versions depending on the engine and the date of manufacture.
Inline filter(5) & Exchangable filter(10):

Is there any way to know which filter you have before starting the project? i.e. prior to 2011 it was inline and after that #10? Seems like most everyone so far has had the exchangeable filter.

[theweebabyseamus]

Is there any way to know which filter you have before starting the project? i.e. prior to 2011 it was inline and after that #10? Seems like most everyone so far has had the exchangeable filter.

A dealer should be able to tell you off your VIN. Good luck on being the in-line filter. Lol

[SR7D1]

Does anyone have part numbers on the rear diff drain/fill plugs?

[MME1122]

Does anyone have part numbers on the rear diff drain/fill plugs?

Audi part# N90281802

https://www.ecstuning.com/b-genuine-...ach/n90281802/

I don't even have the DSG and I read through the whole guide because it was so well written lol. Nice job.

[SDV325]

With the urgency to the DSG fluid being changed every 35K miles, is there any recommended change interval for the center diff/DSG gear oil part of the transmission? Rear differential? Or are they being done for peace of mind at this point? Im only at 55K miles (second DSG fluid/filter this spring), not terribly worried at this point but it's on the radar for sure.

[theweebabyseamus]

IIRC center diff/trans gears and the rear diff is 100k.

The first DSG service is 35k and the rest are 40k.

[SDV325]

IIRC center diff/trans gears and the rear diff is 100k.

Seems to be the norm for differentials that use 75w90 fluids from previous cars.

Thanks

[SR7D1]

Yes, that was the procedure I approximately followed when doing the DSG service on my mk5 GLI. The B8 S4 is easier in some ways (dedicated fill plug versus filling through the drain), and harder in some ways (have to drop the pan and change the gasket versus only changing the cartridge). Neither is particularly difficult though. Just time consuming.

I've updated the thread with some new pictures and have put together an outline of the center diff service.

Dave, I plan on doing this in the Spring and have most of the parts already. 2 questions:

Did you reuse the drain/fill plugs for the center diff? (part number for the fill the same as the rear diff? Drain plug looks different for sure.)

Have you experienced any downside to using non-oem fluid in the center diff? (binding/whining)

[SR7D1]

Audi part# N90281802

https://www.ecstuning.com/b-genuine-...ach/n90281802/

I don't even have the DSG and I read through the whole guide because it was so well written lol. Nice job.

Thanks! I was looking for those!

[tsitalon1]

Remove the cross-brace support under the transmission pan by removing the 6 18mm bolts holding it to the subframe (green). You will need to remove a 10mm nut attaching the power steering line to the top of this brace before it can be removed.[/LIST]

Looked through this thread, the Tech Manual and all over this forum. Maybe I missed it somewhere, but my cross brace has 2 Torx type bolts closest to the front.

This article and all other references I"ve seen only mention 18mm bolts, but mine has 4 18mm bolts and two odd ball Torx type bolts.. They look to be the size of a T-60, but have may more points, maybe 2 or 3 times as many points.

Anyone know what tool I need for these?

As much as I'd like to do this, I'm stuck looking at the bolts and am a but puzzled as I haven't seen a bolt head like this before.

they look like these:
https://www.ecodetuning.com/eurocode...ab-description

[whiped]

Usually, they are M10 XZN aka triple square.

[tsitalon1]

Usually, they are M10 XZN aka triple square.

Thanks!

So looks like I need this:
http://a.co/dK1oRvV

I've ordered it - wish I knew ahead of time :(

[whiped]

That sucks :( I have a set similar to the one you linked.

They carry them at a lot of autoparts stores if you don't want to wait.

[tsitalon1]

Checking around now....

This sucks, come on Audi! What could possibly be the technical reasoning behind making only these two bolts different

Makes zero sense!!

[whiped]

They use those bolts for a lot of structural things...

Subframe, sway bars, crank pulley, body panels, etc.

[tsitalon1]

They use those bolts for a lot of structural things...

Subframe, sway bars, crank pulley, body panels, etc.

I'm just being sour - I get it, just don't see how it's structurally stronger than a standard hex bolt head - Seems just being difficult because they can.

25+ years of working on mostly Japanese cars and I've never seen this type of bolt :(

[tsitalon1]

Got the DSG done, super simple with the right tools :)

Though I was only able to get ~5.5qts back in, verified 3 times...hmmm.

Used a level on the car before (while in garage) and after (on jacks) both times indicated as level.

[theweebabyseamus]

Got the DSG done, super simple with the right tools :)

Though I was only able to get ~5.5qts back in, verified 3 times...hmmm.

Used a level on the car before (while in garage) and after (on jacks) both times indicated as level.

About right. Congrats, once you finish it you kind of wonder what all the fuss is about eh?

[tsitalon1]

About right. Congrats, once you finish it you kind of wonder what all the fuss is about eh?

Absolutely, with a lift this is a 30-45 min job tops!

I spent most my time jacking up the car and moving out from under the car multiple times...

I need to look into the mini lift systems at least!!

[SR7D1]

Reserved for center differential/DSG gear oil DIY.

I'm pretty sure it's as simple as:

Parts list:

• 4.5 liters of 75w90 GL-4 synthetic gear oil, part number G055532A2 (or equivalent. I used RedLine MT-90. DO NOT use a GL-5 rated oil*) You may see the oil referred to as "manual transmission oil", which is expected. We are servicing the half of the DSG transmission that is the same as a manual transmission.

Optional: Replacement drain and fill plugs.

*Notes: The center differential shares oil with the DSG transmission's gears and synchros. This is why the capacity is so large, and also why it's so important that the oil you use is GL-4 rated, and NOT GL-5 rated. GL-5 rated oils contain additives that have been known to eat away at brass transmission components such as gear synchros. This is not an issue in the rear differential, which is why we used GL-5 oil in it.

Procedure:

1. Jack up the car and ensure it is level. If available, use a lift.
   
   
   
2. Remove center differential FILL plug with a 10mm hex bit (same as DSG fill/drain plugs). We are removing the fill plug first so that if you can't get it to budge, you will be able to drive your car to a shop to get it worked on, rather than being stuck with a drained differential.
3. Remove center differential drain plug with a 10mm hex bit and allow gear oil to drain into a clean container. A container with measurements is a plus so you can ensure you refill approximately the same amount of fluid you drain out.
4. Reinstall drain plug and torque to 45nm.
5. Pump in ~4.5L of the GL-4 75w90 synthetic gear oil, until the oil begins to run out of the fill hole.
6. Reinstall fill plug, torque to 45nm.

However, it's possible that the transmission mount will have to be removed to get at the drain plug. In which case there will be additional steps before and after. I will update once I have performed the service.

Does anyone have a part # for the center diff drain plug?

[RobertViper]

Is it worth paying ~$60 more for the genuine Audi filter as opposed to the Vaico? I’ll absolutely do it if there is a compelling reason to do so.

[SR7D1]

Is it worth paying ~$60 more for the genuine Audi filter as opposed to the Vaico? I’ll absolutely do it if there is a compelling reason to do so.

I used Liqui Moly 8100 both times on my changes, no issue, shifts perfect.

https://www.europaparts.com/dsg-tran...5-7-speed.html

[Raiden]

amazing thread, thank you all so much !

[Bratcop]

Here are the parts and parts numbers for my dsg (2013 S4) external cooler filter and o-ring gasket fyi

Sent from my LG-US996 using Tapatalk

[Bratcop]

So I completed this with the transmission fluid change kit from Blau parts. It included Ravenol fluid... All went well. Does anyone realize that audi simply installed an oil absorbent mat under the tranny rather than fix any oil leak issues...?

Anyway I thought I might help clear up the debate about whether the internal filter is a filter or a strainer. I cut my old one apart... Definately a filter and not just a strainer

Sent from my LG-US996 using Tapatalk

[BSIX-SFOUR]

Reserved for center differential/DSG gear oil DIY.

I'm pretty sure it's as simple as:

Parts list:

• 4.5 liters of 75w90 GL-4 synthetic gear oil, part number G055532A2 (or equivalent. I used RedLine MT-90. DO NOT use a GL-5 rated oil*) You may see the oil referred to as "manual transmission oil", which is expected. We are servicing the half of the DSG transmission that is the same as a manual transmission.

Optional: Replacement drain and fill plugs.

*Notes: The center differential shares oil with the DSG transmission's gears and synchros. This is why the capacity is so large, and also why it's so important that the oil you use is GL-4 rated, and NOT GL-5 rated. GL-5 rated oils contain additives that have been known to eat away at brass transmission components such as gear synchros. This is not an issue in the rear differential, which is why we used GL-5 oil in it.

Procedure:

1. Jack up the car and ensure it is level. If available, use a lift.
   
   
   
2. Remove center differential FILL plug with a 10mm hex bit (same as DSG fill/drain plugs). We are removing the fill plug first so that if you can't get it to budge, you will be able to drive your car to a shop to get it worked on, rather than being stuck with a drained differential.
3. Remove center differential drain plug with a 10mm hex bit and allow gear oil to drain into a clean container. A container with measurements is a plus so you can ensure you refill approximately the same amount of fluid you drain out.
4. Reinstall drain plug and torque to 45nm.
5. Pump in ~4.5L of the GL-4 75w90 synthetic gear oil, until the oil begins to run out of the fill hole.
6. Reinstall fill plug, torque to 45nm.

However, it's possible that the transmission mount will have to be removed to get at the drain plug. In which case there will be additional steps before and after. I will update once I have performed the service.

How often does the Center Diff need to have fluid replaced? Didn’t think I saw that part on here? Maybe I mis-read?


Sent from my iPhone using Audizine

[JasonHood]

I found the difference between the existing and new pan bolts to be pretty striking. Thought I would try to sneak by using the existing pan bolts since this was the first transmission service. Mistake. Snapped one off in the bottom of the transmission and had two or three others that I could feel were starting to twist on themselves and daring me to keep going! Pulled them all, even the broken one came out easily when harassed with a drill bit on reverse, and ran to the dealer for new ones. The new ones went in smoothly, confidently and triggered the torque wrench "click" consistently at 12 ft lbs. So save yourself the time and elevated heart rate and get new one-time use trans pan bolts.

Was just reading through and caught this - 10 ft lbs = 13.5 Nm. The pan should be torqued to 10-12 Nm. Still should replace the bolts, just wanted to mention the ft lb vs. Nm difference.

[JasonHood]

I just did mine, 2010 and it did not have the small cooling filter cartridge. I used about 6.5 liters of fluid as well.

One thing I will add is that when installing the internal filter for the DSG, it should wiggle it's way in and stop once it's inserted far enough so that no more of the orange rubber is showing. On the top side of the filter you will see a plus symbol that is raised, this lines up in a cylinder hole on the inside of the casing. It acts as a guide to ensure the filter is seated in the correct position.

Thanks for the write up mate!!@

slave of corruption

O-ring part number WHT003379 goes over the + on the top of the cartridge. I don't think I saw it mentioned anywhere else. Used this sticky today and it made life way easier!

[minman26]

where is everyone checking to make sure level?

[theweebabyseamus]

The fill hole. Should just barely trickle out when the car is perfectly level and fluid temp is between 30-50*c iirc.

[c25porter]

I feel like it is a dumb question, but I poured through the whole thread to try to figure it out and couldn't. For the rear sports diff, what fluid goes in the passenger side and what fluid goes in to the driver side? I saw gear oil and ATF, I assume the gear oil is the 75w90 and the ATF is the same fluid as the DSG, is that correct?

[DaveLinger]

I feel like it is a dumb question, but I poured through the whole thread to try to figure it out and couldn't. For the rear sports diff, what fluid goes in the passenger side and what fluid goes in to the driver side? I saw gear oil and ATF, I assume the gear oil is the 75w90 and the ATF is the same fluid as the DSG, is that correct?

No. All of that detail is in post #2. It's a very specific Audi Gear Box Oil for the "ATF", and the gear oil must be 75w90 GL-5 (as specified in the post, in bold).

[evil35r]

Did this today with car level drained roughly 5 quarts. When I took the fill plug out about a half a quart came out so maybe Audi filled it cold and plugged it and sent me on my way last time. Just changed the external filter and put back in roughly 4.5 quarts started the car ran for a min out in another .5 quarts and with the car on it started to run out when it got to temp needle for engine temp halfway I waited for it to quick drip and plugged it. So got back in 5 quarts of amsoil. Over all not that hard def sucks on jack stands. I rate it a 5 out of 10 for hardness just time consuming.

[theweebabyseamus]

Did this today with car level drained roughly 5 quarts. When I took the fill plug out about a half a quart came out so maybe Audi filled it cold and plugged it and sent me on my way last time. Just changed the external filter and put back in roughly 4.5 quarts started the car ran for a min out in another .5 quarts and with the car on it started to run out when it got to temp needle for engine temp halfway I waited for it to quick drip and plugged it. So got back in 5 quarts of amsoil. Over all not that hard def sucks on jack stands. I rate it a 5 out of 10 for hardness just time consuming.

I wouldn't do it on jackstands again personally. I did that the first time and I used a bubble level to make sure it was level, since it has to be level side to side and front to back, and when I rechecked it later on a lift I had definitely overfilled it.

[evil35r]

I took out 5 quarts measured it... I put in about the same maybe slightly less.

[TC_S4]

Attachment 88357
Does anyone know where that O-ring goes?

[s4inctown]

If I remember correctly it goes on the top of that white cooling filter

[s4inctown]

Actually take that back, that looks like the small one that goes on the plus symbol of the black filter. That stupid filter does not stay in place, but just line it up so when you put pan back on it goes into place. I actually had a buddy use a thin plastic scraper to hold it in place while lifting pan up. Scraper was thin enough to get pan close enough to hold it place.Screenshot_20181010-234928.jpeg