F86 Transfer Case Replacement: Car Ninja

[Dgjo2022X5MC]

Hopefully you don’t need to, but here is a great video of f86 transfer case replacement.

My f86 needs one at about 45k miles. Replaced by BMW. Felt like a misfire under load.

Car Ninja makes very good videos.

Enjoy.

https://youtu.be/E_t4d8JnIW4?si=D325ZSqxZowpEuti

[dentprotony@gmail.com]

Probably a better idea would be to rebuild your current one, job is fairly straightforward and rebuild kit with chain, seals, friction plates is around 700 from cobra transmission, basic tools and skills will get you a fresh tcase in 4-5hrs or less

[Dgjo2022X5MC]

Originally Posted by dentprotony@gmail.com

Probably a better idea would be to rebuild your current one, job is fairly straightforward and rebuild kit with chain, seals, friction plates is around 700 from cobra transmission, basic tools and skills will get you a fresh tcase in 4-5hrs or less

Good info for current owners as I have moved on to a F95. I would think you could rebuild the clutch packs and internals like and automatic transmission. Not sure about adaptations and programming. Beyond my pay grade.
They reloaded mine under factory warranty. This is why I think if you tune these things the xfer case is your weak point. The transmission is a beast.

[dentprotony@gmail.com]

Originally Posted by Dgjo2022X5MC

Good info for current owners as I have moved on to a F95. I would think you could rebuild the clutch packs and internals like and automatic transmission. Not sure about adaptations and programming. Beyond my pay grade.
They reloaded mine under factory warranty. This is why I think if you tune these things the xfer case is your weak point. The transmission is a beast.

Yep tranny will hold a ton of power, tcase could be a weak point for sure, wish they had more fluid capacity in it but oh well. Tcase is fairly easy to rebuild, calibrations can be done via a proper scanner, otherwise easy. If I rebuild mine in the next few months ill make a step by step to help fellow f85/f15 owners

[Dgjo2022X5MC]

I don’t think I have EVER seen an automatic transmission issue post. I’m sure there are defects here and there, but when you consider the volume of activity on these forums, the absence of ZF (or even GM units on older BMWs) issues is pretty telling.

[pachieh]

Originally Posted by Dgjo2022X5MC

Hopefully you don’t need to, but here is a great video of f86 transfer case replacement.

My f86 needs one at about 45k miles. Replaced by BMW. Felt like a misfire under load.

Car Ninja makes very good videos.

Enjoy.

https://youtu.be/E_t4d8JnIW4?si=D325ZSqxZowpEuti

Interesting, been trying to troubleshoot something maybe similar to you, have a recent separate thread about it. Feels a little like a misfire or a mild thudding at low acceleration. Perfectly fine under load.

[dentprotony@gmail.com]

Originally Posted by pachieh

Interesting, been trying to troubleshoot something maybe similar to you, have a recent separate thread about it. Feels a little like a misfire or a mild thudding at low acceleration. Perfectly fine under load.

Maybe unplug the tcase see if that changes anything (or pull the fuse)

[Dgjo2022X5MC]

Originally Posted by pachieh

Interesting, been trying to troubleshoot something maybe similar to you, have a recent separate thread about it. Feels a little like a misfire or a mild thudding at low acceleration. Perfectly fine under load.

Mine was a slight misfire feeling when accelerating. Would not manifest all the time, but seemed like something that needs some load to cause the slippage.

[pachieh]

Originally Posted by dentprotony@gmail.com

Maybe unplug the tcase see if that changes anything (or pull the fuse)

Does turning off DSC and MDM have the same effect as this?

[srybicki]

No

[///Motivated]

Had the same feeling. $30 fluid change and everything is right with the world (as judged from the confines of my 20’ x 20’ garage).

[CryptoHeff]

Originally Posted by dentprotony@gmail.com

Yep tranny will hold a ton of power, tcase could be a weak point for sure, wish they had more fluid capacity in it but oh well. Tcase is fairly easy to rebuild, calibrations can be done via a proper scanner, otherwise easy. If I rebuild mine in the next few months ill make a step by step to help fellow f85/f15 owners

Love your work. And looking forward to getting your front driveshaft in.

I think I've got some issues with my transfer case and mechanic is going to look into.

We got it up on a hoist for a quick diagnosis. Turned off all the traction control and was expecting the front wheels to spin in drive and they didn't... I would have expected all wheels to drive in gear under throttle.

I had only seen rebuild kits for transfer case on bimmerworld - so good to know about cobra transmission.

Is this really the same transfer case in the Ms that are in all the other models? ATC45L? No wonder they're a weak point, if so.

[dentprotony@gmail.com]

I would recommend changing the fluid and doing adaptations, this worked fir many to help with tcase issues. Maybe good idea to unplug tcase and see if this changes anything for you




QUOTE=CryptoHeff;30603472]Love your work. And looking forward to getting your front driveshaft in.

I think I've got some issues with my transfer case and mechanic is going to look into.

We got it up on a hoist for a quick diagnosis. Turned off all the traction control and was expecting the front wheels to spin in drive and they didn't... I would have expected all wheels to drive in gear under throttle.

I had only seen rebuild kits for transfer case on bimmerworld - so good to know about cobra transmission.

Is this really the same transfer case in the Ms that are in all the other models? ATC45L? No wonder they're a weak point, if so.[/QUOTE]

[Dgjo2022X5MC]

[QUOTE=CryptoHeff;30603472]Love your work. And looking forward to getting your front driveshaft in.

I think I've got some issues with my transfer case and mechanic is going to look into.

We got it up on a hoist for a quick diagnosis. Turned off all the traction control and was expecting the front wheels to spin in drive and they didn't... I would have expected all wheels to drive in gear under throttle.

I had only seen rebuild kits for transfer case on bimmerworld - so good to know about cobra transmission.

Is this really the same transfer case in the Ms that are in all the other models? ATC45L? No wonder they're a weak point, if so.

I think it is generally similar, but there are M variant adaptations and strengthening per the tech manual. Looks like the actual xfer case started out on the F12 models, which was adapted to F90. I may have read that wrong. See attached images from the tech manual. I included F85/6 and F95/6 info. Looks to be little to no power sent to front axles from what I read.

[CryptoHeff]

Thanks for sharing. I'm going to have to do some more reading too.

[Dgjo2022X5MC]

Originally Posted by CryptoHeff

Thanks for sharing. I'm going to have to do some more reading too.

NP. Good luck! I would definitely flush and replace fluid before replacing parts. If it’s low on fluid, though, it’s leaking. That’s a problem...

[CryptoHeff]

Cheers. No leaks and did a fluid change about 20k kms and a recalibration. All seemed okay then.

[Dgjo2022X5MC]

Sure beats a $4K transfer case!

[CryptoHeff]

Interestingly it's rare for F85s to be wrecked where I am, and there is one currently being parted out and both the front diff and transfer case are already sold.

I might just go down the rebuild route to be honest. Can't fathom how expensive whole units are.

[dentprotony@gmail.com]

Yep, ill try to find a YouTube link with our tcase rebuild, its by the guys that dont speak English but everything is shown step by step


it

Originally Posted by CryptoHeff

Interestingly it's rare for F85s to be wrecked where I am, and there is one currently being parted out and both the front diff and transfer case are already sold.

I might just go down the rebuild route to be honest. Can't fathom how expensive whole units are.

[CryptoHeff]

This is the only one I can find, but it skips the reassembly and I have no idea what they're saying or what was wrong with it lol

https://youtu.be/nDGC3qSqb0w?si=PbSvGWar0jpKsReG

[dentprotony@gmail.com]

Originally Posted by CryptoHeff

This is the only one I can find, but it skips the reassembly and I have no idea what they're saying or what was wrong with it lol

https://youtu.be/nDGC3qSqb0w?si=PbSvGWar0jpKsReG

Yep thats the one i was looking at!