DIY Guide:Transmission/Front Final Drive/Transfer Case/Rear Final Drive Fluids

[202009]

I am starting this thread to compile all information I've gathered so far before starting the fluid change on my 2014 A7 TDI. There is information all over the internet and I thought it would be a good idea to compile it here for future use. If anyone has good information to add post in the comments below and I will edit the main page.

Depending on who you speak to the "lifetime" ZF transmission fluid as well as final drive and transfer case oils have varying change intervals. For the purpose of this thread I will state it's probably best to have them changed every 60k miles as a rule of thumb as there is no precise source I was able to find. For the ZF transmission fluid I've seen emails from ZF themselves saying that it should be changed by 80k miles. Regardless assume 60k to be safe.

OEM Audi fill quantities:




DIY on the transmission fluid:
https://www.audiworld.com/forums/a6-...speed-2919359/
https://www.youtube.com/watch?v=i2SD...71751083629894


DIY on the front final drive:
https://www.audizine.com/forum/showt...ZF8-automatic)


Missing: DIYs on the transfer case and rear final drive, if someone has links to share I will update here.


General Parts list beyond your tools based on best prices I was able to find. ECS Tuning seems to lead the way here, if you can recommend better suppliers please post below:

Transmission Fluid Service Kit: $335
https://www.ecstuning.com/b-assemble...t/g060162a2kt/

Front Final Drive Oil: 1L $27
https://www.ecstuning.com/b-genuine-...ter/g052145s2/

Transfer Case Oil: 1L $93
https://www.ecstuning.com/b-genuine-...ter/g055145a2/

Rear Final Drive oil: 1L $27
https://www.ecstuning.com/b-genuine-...ter/g052145s2/


In addition you will need a VAG COM or the ECS Scan Tool to measure the temperature of the transmission while the car is running to complete the service $230
https://www.ecstuning.com/b-schwaben...868sch01b~scf/

I plan on tackling this in the coming months and will update as I am going through it, would be awesome if others chime in with additional info.

[FourRingThing]

Nice work thanks. I am getting close to doing this too.

[202009]

Fluids arrived:





My garage floor is sloped so I had to use shims with the rear jack stands to get the car level.


Youtube DIY video on the topic linked above


Idling car to bring transmission to normal operating temp before draining.


Draining tranny


Draining front final drive




To be continued...

[vector78]

Great work and visuals. I am looking to do this job in the future as well.

[202009]

Thanks.

Moving forward, dropped the tranny pan, cleaned it, replaced tranny filter and gasket.

Filled front and rear diff oils, next up is the transfer case and transmission.

Surprisingly this was a lot more straight forward than I expected, no real surprises.

My only recommendation is buy lots of extra hose to pump in fluid. You can share the gear oil hose for front and rear final drives as they share the same fluid. You should have a clean hose for your transfer case and a clean hose for your tranny fluid. This ensures you aren't getting oil residue in whatever you are filling.

I was originally going to use denatured alcohol to clean the pump/tubes but they take too long to dry and even after blowing compressed air through them there is still moisture. To be safe, use new clean hoses.

Old tranny oil


Everything cleaned up and ready to go.


Old tranny filter, the magnets were covered in sludge, anyone know if this is normal amount


Filling front final drive


Filling rear diff, same pump/hose


Preparing to fill transmission.

[MadMaxD]

I’m curious about front diff and center diff/trans fluid for a DSG car. Same thing? I know the DSG hydraulic fluid is different that the gear oil.

[202009]

I believe the DSG is the 7 speed S-Tronic, here are the fill quantities and part #'s for the oil:


It doesn't list a front final drive, I am going to assume like other cars the DSG transmission and front final drive share the same fluid unlike the ZF tranny/front final drive.

Transfer case oil is different. Rear Final drive oil is same.

[202009]

Finished off all fluids with the transmission being last. Couple of notes as there is a discrepancy between the suggested procedure in the manual vs. DIY's on the internet.

Once everything is installed you want to fill your dry transmission. Mine took just under 3L at dry.

The discrepancy is at this step, DIY tutorials online start the engine and run it through the gears at this point, the manual says otherwise.

Once you've filled it up from dry start and run the engine for 20 seconds.

After this step, my car took another 2L

Once topped off (total of 5L) start the engine with drain plug put on loosely and cycle through R/N/D, manual says 3 seconds each, DIY'ers do it for 30-40 seconds. I did it for 40 seconds.

Put car in P, let it idle and remove drain plug and top off fluid. Mine took another few hundred mills while the operating temp of the transmission was 35 degrees Celsius.

All in all roughly 5.5L in total for the fill.

Hope this was helpful.

[JaramA7]

Great job... this should be very helpful!

[vector78]

What was your impression of the Meyle filter kit ? Is the quality equivalent to the OEM you took out?

Thank you

[AudiC7Owners]

I'm about to do a video diy on this for my C7 owners channel. But, in doing research I've found that the cheapest way to do this in terms of getting parts is this:

Option 1: Source things from multiple places (ECS/FCP/Europa Parts) - Doing this will yield a total of $218.86 for all parts when you get a Meyle Filter/Pan gasket kit, and you use ROWWE ATF fluid. But, you will have to pay for shipping from each site you use.

Option 2: Buy the ATF kit from Europa Parts for $227.45 + Shipping - This is the price for their kit with ROWWE ATF fluid. Somehow Europa Parts supplies the OEM drain plug for a mere $12.95 when everyone else wants about $75-$90 for it. Shipping ran me about 22$ for a total of just over 250$ shipped for everything.

To me, the Europa Parts kit is the clear choice. Keep in mind, this is for 9L of fluid. You only need 9L if you are planning on using a fluid evacuater/filler tool to completely remove all the old ATF fluid. If you are using the technique described in this DIY, you won't need all 9L.

Hope this helps

[202009]

I'm about to do a video diy on this for my C7 owners channel. But, in doing research I've found that the cheapest way to do this in terms of getting parts is this:

Option 1: Source things from multiple places (ECS/FCP/Europa Parts) - Doing this will yield a total of $218.86 for all parts when you get a Meyle Filter/Pan gasket kit, and you use ROWWE ATF fluid. But, you will have to pay for shipping from each site you use.

Option 2: Buy the ATF kit from Europa Parts for $227.45 + Shipping - This is the price for their kit with ROWWE ATF fluid. Somehow Europa Parts supplies the OEM drain plug for a mere $12.95 when everyone else wants about $75-$90 for it. Shipping ran me about 22$ for a total of just over 250$ shipped for everything.

To me, the Europa Parts kit is the clear choice. Keep in mind, this is for 9L of fluid. You only need 9L if you are planning on using a fluid evacuater/filler tool to completely remove all the old ATF fluid. If you are using the technique described in this DIY, you won't need all 9L.

Hope this helps

Good call on the ATF Fluid capacity. I used just over 5L of ZF Fluid, so you need 6L max and the "kit" came with 9L, I have 3L extra now.

- - - Updated - - -

What was your impression of the Meyle filter kit ? Is the quality equivalent to the OEM you took out?

Thank you

Hard to speak to quality, based on visual inspection they looked pretty much the same.

[DetRebel]

How does the transmission feel after this service?


Sent from my iPhone using Audizine

[C Cortez]

Thank you for taking the time to gather all the relevant info necessary for this key DIY, and, then documenting the actual work. Great post !

I have a few questions : Why is the Audi transfer gear oil ( G-055-145-A2 ) SO EXPENSIVE @ $ 93 / liter from ECS & $ 71 from Auidionline.com?
Who is the actual OE provider of the OIL ?
What other high quality providers does this forum recommend ?

TIA

[202009]

How does the transmission feel after this service?


Sent from my iPhone using Audizine

Pretty anti climatic to be honest.

My transmission didn't feel bad to begin with and this was routine maintenance. The butt dyno says it might feel a bit smoother at lower speeds, but I have a feeling that's just in my head. The car is as smooth as it always was.

[C Cortez]

Finished off all fluids with the transmission being last. Couple of notes as there is a discrepancy between the suggested procedure in the manual vs. DIY's on the internet.

Once everything is installed you want to fill your dry transmission. Mine took just under 3L at dry.

The discrepancy is at this step, DIY tutorials online start the engine and run it through the gears at this point, the manual says otherwise.

Once you've filled it up from dry start and run the engine for 20 seconds.

After this step, my car took another 2L

Once topped off (total of 5L) start the engine with drain plug put on loosely and cycle through R/N/D, manual says 3 seconds each, DIY'ers do it for 30-40 seconds. I did it for 40 seconds.

Put car in P, let it idle and remove drain plug and top off fluid. Mine took another few hundred mills while the operating temp of the transmission was 35 degrees Celsius.

All in all roughly 5.5L in total for the fill.

Hope this was helpful.

The discrepancy described is likely caused by the existence of a transmission oil cooler. IIRC not all A6 models have had a trans oil cooler.

Here, for your review, is a link to the ZF PDF that describes the ZF recommended process for the ZF 8HP automatic transmission.
The document also has torque specs and drawings for the various types of oil pans, fill and drain plugs.

https://aftermarket.zf.com/remotemed...p-50130-en.pdf

[A665]

Fantastic write-up and photos. Many thanks to the OP.

Please help me with one point: I've always understood that a transmission will not warm-up by idling the car in PARK or neutral, such that it becomes warm only during use (i.e., during driving of the vehicle). Can you confirm that idling motionless is just as effective?

Not a critique of or a challenge to your technique, but rather an honest question.

thanks

[C Cortez]

A665: In the ZF document referenced in my post above, it states that after the first pass at re-filling, one needs to drive the car in order to get the oil cooler valve to open at around 75 degrees Celsius and thus fill the cooler with oil.

The implication being, of course, that just waiting and idling would not raise it that high.

However, i will defer to someone with real life experience to pass on their explicit knowledge that just idling will not raise the transmission oil temperature high enough to open the cooler valve.

[Valpo A7]

A665: In the ZF document referenced in my post above, it states that after the first pass at re-filling, one needs to drive the car in order to get the oil cooler valve to open at around 75 degrees Celsius and thus fill the cooler with oil.

The implication being, of course, that just waiting and idling would not raise it that high.

However, i will defer to someone with real life experience to pass on their explicit knowledge that just idling will not raise the transmission oil temperature high enough to open the cooler valve.

Sorry to revive a 2019 thread. I was researching transfer case oil change and this came up.

As to heating up the oil in the trans cooler. There is so little oil in that cooler that it should not matter. I just had the engine and trans out of my car for timing chains and I prefilled the cooler when reinstalling it. The cooler took less than 1/3 quart to fill. There should be very little expansion from that volume of oil.


Now as to the transfer case and diff oils. The diff oil is a GL5 oil from what I have researched while the transfer case is a GL4 oil. Any GL4 will work for our cars. BUT I also found that GL5 can safely replace GL4. I changed my diffs and transfer case when I had the engine out with Valvoline GL5. All is working fine in my car.

The previous owner took life time to heart and this was the first time the diffs and transfer were changed at 205,000 miles on mine. Sorry for the sideways pic but this is what the diff and transfer looks like at 205,000 miles. No burned smell at all to it, just dark

56F9C99B-D05A-4713-A818-50B23AB56D9E.jpg