Transfer case fluid replacement prohibition?

[lk0]

On my 2015 Hyundai Genesis, Hyundai states:

Prohibition on checking, refilling and replacing the transfer case oil

- Do not check, refill and replace the transfer case oil because the oil for the transfer case only (ultra-low viscosity of ATF SHELL TF 0870) is filled when coming out of the factory.
- Do not check and replace the oil.
- No drain plug
- In case that the transfer case (AWD) oil-related failure code (DTC) appears, replace the transfer oil case assembly.

This car uses a TC from Magna; it's said to be similar to Magna units used on BMWs/Porsches. Some people on a Genesis forum have changed the oil through the fill plug, and have noted improvements in jerky acceleration and for the most part have had no issues (link; people start changing the fluid on pg 5). I don't think anyone did any kind of GDS calibration with it either.

I don't know much about constantly active wet clutch systems like this. My question is, what damage can be done by changing the fluid? Changing TC fluid is a normal procedure on most cars, what are the chances that this system is significantly different and can be damaged in some way?

I'm at 124k miles and it's one of the only fluids I have yet to replace on this car.

 

[GMBoy]

Very interesting. I looked in Alldata and it shows exactly what you said. It also lists .5 labor to do a fluid change. Since it shows what fluid to use I would go and replace it unless the reason is that there is no access to fill it. IDK, never saw a Genesis but it does peak my interest in that they specifically state not to service it. If using the same correct fluid I see no reason any damage would come.

 

[GMBoy]

Also -just reviewed the t-case replacement procedure and there is NO fill or drain plugs I can see in the diagrams or the color photos. I do see the breather where if you could get to it you might be able to suck out, measure and replace with the same amount of new oil but there is literally no room to get to much and the T-case sits almost against the floor board - very tight. The interesting thing is the service procedure says to not tip the unit or oil will spill out even with breather installed - tells me that the NEW replacement unit comes already filled with oil. This seems like the most sealed for life component I have ever seen! Crazy!

 

[dishdude]

Sounds like something you don't want to mess with. I guess they've concluded the fluid doesn't need service and the risk of the wrong fluid being used or the level being incorrect is a greater risk than the lifetime fill.

 

[Timmastertech]

Also -just reviewed the t-case replacement procedure and there is NO fill or drain plugs I can see in the diagrams or the color photos. I do see the breather where if you could get to it you might be able to suck out, measure and replace with the same amount of new oil but there is literally no room to get to much and the T-case sits almost against the floor board - very tight. The interesting thing is the service procedure says to not tip the unit or oil will spill out even with breather installed - tells me that the NEW replacement unit comes already filled with oil. This seems like the most sealed for life component I have ever seen! Crazy!

Service procedure for replacing the output shaft seals shows where the fill plug is and the refill procedure, but there doesnt appear to be a drain plug

 

[lk0]

I went back to that Genesis forum thread, it looks like most of the posts about changing the fluid were from 2018+ Genesis owners.. the 2015-16 Hyundai Genesis (sedan) became the Genesis G80 in 2017, but it's the same car. I swear I checked before and I had a fill plug right where it should be according to the pictures people posted on that forum, no drain plug though obviously.

 

[lk0]

 

[edyvw]

TF0870 is BMW fluid from 2006. It absolutely has to be changed. BMW although it claims its fluids are lifetime, will throw 4x4 code once TC cannot operate properly. However, BMW provided drain and fill plugs. You have numerous TF0870 options, from BMW DTF1 (probably best), Ravenol DTF1, Vaico, Valeo, Febi etc.
Ravenol did testing of these fluids and BMW DTF1 is most shear stable.
I personally would evacuate fluid through fill plug and add new one.

 

[Hall]

Interesting that they tell you the specific OEM fluid they used. I'm not clear if you have a fill plug (or breather) or not and even if you do, looking at the image the TC shown, good luck getting more than 1/2 the original fluid out by suction. Looks like a lot of nooks and crannies in the internal cavity for fluid to settle into. I guess you could replace what you can, drive it, replace more, drive it, and repeat until you're happy that enough fluid has been replaced.

 

[SEBZX79]

My 17 x5 uses ATC45l transfer case. There is no drain plug just need to suck it out and fill until drips. Not hard to do but needs to be done and recalibrated.

 

[Stimp]

Google doing a TC fluid change on a BMW with xdrive. Seems like many if not all of them use this fluid and do not have drain plugs.

 

[BMW Dom]

BMW DTF1 Transfer Case Fluid (1 Liter) - Shell 83225A4F016

BMW DTF1 Transfer Case Fluid (1 Liter) - Shell 83225A4F016

www.fcpeuro.com

 

[dfarr67]

Didn't Magna buy Borg Warner?