DIY F85/86 Differential Fluid Change

[Blue By You]

Originally Posted by Chilled

did you end up triggering "QMVH transmission oil change", because to me it looks like it only applies if you do the clutch pack sides.

Do any codes show up if I get my actual transmission serviced?

[SaNGRia]

Originally Posted by Chilled

did you end up triggering "QMVH transmission oil change", because to me it looks like it only applies if you do the clutch pack sides.

I will do soon 🙌🏼

[Chilled]

Originally Posted by Blue By You

Do any codes show up if I get my actual transmission serviced?

Depends on how badly you mess up. Impressively yes, you will get allot of error codes.

In short, no there should be no codes.

However there is a Transmission Adaptation reset bit, and then a driving process to combeite the adaptation. If you dont, you may be in for some hash shifts. Search around, there is a few good threads on this.

[Blue By You]

Originally Posted by Chilled

Depends on how badly you mess up. Impressively yes, you will get allot of error codes.

In short, no there should be no codes.

However there is a Transmission Adaptation reset bit, and then a driving process to combeite the adaptation. If you dont, you may be in for some hash shifts. Search around, there is a few good threads on this.

My indy shop is doing it. Just making sure the dealer won't see that the tranny has been serviced since it is a "sealed unit..."

[Chilled]

Ahh, I'm not a 100 on this. I do remember reading that there was some sort of a counter that keeps track of how many times the Adaptation has been reset.

Now I don't remember if that was relating to the Transfer Case/ Diffs or the Transmission.

[SaNGRia]

Had been 200 miles with 1.2L fluid on my rear diff with 0 issue and 0 leak while ALL hard drive condition. Cheers (35k mileage)

[Chilled]

So I did my rear centre section and it also drained approx. 1.2L Colour wise, not as bad as the Transfer Case. I'm at 50Km(30ish mile).
Centre Section.


Also did the Transfer Case, and as everyone says the colour is awful.


I did some custom tooling . (cut most of a socket off, allen key and was able to fit a ratchet and a torque wrench in I did cut a bit too much off the socket tho.).


Also decided to stick borescope into the TC, and yep it really needs a drain plug. There looks like some baffle/sections that run the length of the TC that are internal. I was only able to get 600ML before giving up.

[SaNGRia]

Originally Posted by Chilled

So I did my rear centre section and it also drained approx. 1.2L Colour wise, not as bad as the Transfer Case. I'm at 50Km(30ish mile).
Centre Section.
Attachment 2732831

Also did the Transfer Case, and as everyone says the colour is awful.
Attachment 2732832

I did some custom tooling . (cut most of a socket off, allen key and was able to fit a ratchet and a torque wrench in I did cut a bit too much off the socket tho.).
Attachment 2732833

Also decided to stick borescope into the TC, and yep it really needs a drain plug. There looks like some baffle/sections that run the length of the TC that are internal. I was only able to get 600ML before giving up.
Attachment 2732835
Attachment 2732836

What did u use the get the TC fluid out? I have an electric suction unit which i will use for the TC. And is the fluid pump that goes on the top of the bottle is enough for the refill? And as i said before BMW procedure wrong about the fluid amount! Thank you for sharing!

[Chilled]

Originally Posted by SaNGRia

What did u use the get the TC fluid out? I have an electric suction unit which i will use for the TC. And is the fluid pump that goes on the top of the bottle is enough for the refill? And as i said before BMW procedure wrong about the fluid amount! Thank you for sharing!

I used a 1.5L Fluid Extractor to pull and fill. I was trying to use something small so that there isn't much waist in the hose/housing. I did end up adding a small plastics tube with a 180° bent steel tube to the end of the one that came with the 1.5L. This was to reach the bottom of the transfer case. Something similar to the hook on this one.


Fluid wise, I used the BMW OEM DFT1 1L "83222409710" and that was plenty. When I opened the fill/drain plug, it started to drip out slowly. So when i did the fill i topped up to the point when it started to just slightly drip and sealed it up.


1.5L Extractor. Not this one, but looks exactly like this.
https://www.amazon.com/Mityvac-MVA68.../dp/B0741G9P6R
Just FYI, with the nosel the way it is on this, you will NOT be able to get to the bottom of the TC pan. It wont turn 180°. You will need to add something that can be turned and face the bottom of the TC.

[SaNGRia]

What do you think? I have this to extract the oil which i use for my jetski as well



And fill the TC back from the bottle

[Chilled]

Both should be fine. The pvc pipe should have plenty of flex, so it should be able bend downwards towards the bottom of the TC.

It took several attempts and repositioning to get the it that low. My 180° steal bend kept hitting those baffles, bottoming out on the top bit in pic one and then the flat bit pic2.

But by this point I already had just under 600ml out.

Next time ima try making a 90° bend pipe, and see if that can reach further in.

[SaNGRia]

Originally Posted by Chilled

Both should be fine. The pvc pipe should have plenty of flex, so it should be able bend downwards towards the bottom of the TC.

It took several attempts and repositioning to get the it that low. My 180° steal bend kept hitting those baffles, bottoming out on the top bit in pic one and then the flat bit pic2.

But by this point I already had just under 600ml out.

Next time ima try making a 90° bend pipe, and see if that can reach further in.

You are good



Special Pump : )



Torque :

[Chilled]

I saw that hand pump, I feel sorry for anyone having to pump that out manually.

My next problem for the moment is trying to find some o-rings for the drain plugs. I decided to put in the Tuner Magnetic Plugs for the TC and drain of the diff. The replacement o-rings for them are like $3 each, that seems abit much for a 22mm oring.

The challenge is finding these are a decent price that are rated for 150C°


Plugs
https://www.ecstuning.com/b-turner-m...027030tms01~a/

Replacement o-ring.
https://www.ecstuning.com/b-turner-m.../2418t126~tms/

[SaNGRia]

Originally Posted by Chilled

I saw that hand pump, I feel sorry for anyone having to pump that out manually.

My next problem for the moment is trying to find some o-rings for the drain plugs. I decided to put in the Tuner Magnetic Plugs for the TC and drain of the diff. The replacement o-rings for them are like $3 each, that seems abit much for a 22mm oring.

The challenge is finding these are a decent price that are rated for 150C°


Plugs
https://www.ecstuning.com/b-turner-m...027030tms01~a/

Replacement o-ring.
https://www.ecstuning.com/b-turner-m.../2418t126~tms/

I am gonna use the one time use plugs. They re identical to diff plugs right?

[Chilled]

Yep, front diff, rear diffs(all sections) and TC all share the same plugs.

I just thought it would be a good idea to add the magnetics ones in. I'm only using them on the drain ports for the diffs and fill for the TC. I didn't want to go with the ECS ones as they are aluminum and apparently allot of people are snapping them.

[SaNGRia]

Originally Posted by Chilled

Yep, front diff, rear diffs(all sections) and TC all share the same plugs.

I just thought it would be a good idea to add the magnetics ones in. I'm only using them on the drain ports for the diffs and fill for the TC. I didn't want to go with the ECS ones as they are aluminum and apparently allot of people are snapping them.

It is a good idea but never had any problem without them either

[Franktea1$]

Originally Posted by Yuille36

I just did this a few months, your rear differential has three fill plugs and three drain plugs. The outside chambers use 75w140 and center section uses 75w90.
I would recommend purchasing ECS Tuning, magnetic drain plugs, you only need three. These same drain plugs work on the transfer case and front diff.
If your going to change your rear differential fluid, I recommend that you also change the front diff and your transfer case. I also wrote up a post of this already with photos.

Hi was wondering how the old fluid looked? When I have done these in the past the oil many times seemed like new.

Thanks,
Frank

[Yuille36]

Originally Posted by Franktea1$

Hi was wondering how the old fluid looked? When I have done these in the past the oil many times seemed like new.

Thanks,
Frank

The oil that was removed looked good, as it's only function is to lubricate and cool the differential. But the oil does break down after of a lot years and miles.

[Chilled]

Originally Posted by Franktea1$

Hi was wondering how the old fluid looked? When I have done these in the past the oil many times seemed like new.

Thanks,
Frank

As per above, i did mine at 50KM, and the TC looked pitch black. The photo with the LED light, is the new vs old for the TC. The 1.2L was the rear diff.

[MBoss_F86]

I used Redline for my engine oil and I am very happy with it. So I decided to go with them for Diffs and TC as well for my X6M and C300. Much cheaper on OEM oils. My car has 47k miles now and I will do service at 50k

For F86/F85

Transfer case - https://www.redlineoil.com/mt-lv-70w75w
Front Diff - https://www.redlineoil.com/75w85-gl-5-gear-oil
Rear Diff(all 3 chambers) - https://www.redlineoil.com/75w90-gl-5-gear-oil - Technical rep said you can use this for outer and middle chambers since it is compatible with both SAF Carbon mod and SAF-XO.

[SaNGRia]

5k miles later, my mid section bone dry and 0 issue. So putting 1.2L was correct and no harm! I havent replaced the outer or front diff yet and i am at 40k now. I just changed the TC fluid and it was off -13 degree in 2 years of drive with stock wheels. But that numbers might come from me not tightening the metal guard when i did my water pump replacement and caused brandnew front tires to be destroyed within 1k. Since then i havent done any calibration on the vehicle but considering that tray also tightens up the front subframe , that can cause misalignment on TC and i was getting vibration during that time.

Luckily problem solved after torquing them correctly. And after replacing the TC fluid with calibration, car feels great. Will change the front diff soon with the same oil i used for the rear mid

I was able to drain 600ml exact oil from the TC with electric pump.

[sly1types]

When you guys did the rear diff, did you reset the adaptions? Can you use something other than ista?