[dreamspeed]

I've been searching but there isn't a lot of DIY info on X3s... found a few posts about the E83 X3 but there's next to nothing on the F25 X3.


For the front and rear differential fluid change, this is just a normal drain and fill procedure correct? Keep pumping fluid into the fill hole until it overflows then close it up? Are there any fancy reset procedures like the transfer case?

For the tranny fluid, if I don't want to replace the filter+pan yet, can i just drain the fluid then put back the same amount? Any fancy reset procedures? Or just drain and fill?

Thanks

[X3emist]

On the transfer case, if you do it, the computer has to be reset to tell it there is fresh fluid. I know that sounds ridiculous but google it.

[dreamspeed]

Originally Posted by X3emist

On the transfer case, if you do it, the computer has to be reset to tell it there is fresh fluid. I know that sounds ridiculous but google it.

Yah I've read that which is why I'm prob going to hold off on the transfer fluid for now.

Just want to know what the deal is with the diff fluids so I don't run into any surprises once I get the car up on jacks and start unbolting things

[Asianoak]

I'm not 100% positive but pretty sure I read that there aren't any comp resets required for the diffs. There certainly wasn't for the E90s or Z4s so don't see why BMW would suddenly change it considering the fact they basically consider the diffs non serviceable and lifetime.

[dreamspeed]

Just an update to help others in the future.

According to the BMW TIS info.

Drain front diff and refill with 600ml of fluid, do not fill until overflow.

However, after i drained the fluid and measured out 600ml to put back in, it was already overflowing by the time i got all 600ml into the diff....

Not sure what is up with that, I imagine 600ml is probably right at the fill line...and realistically it's not going to make much of a difference.

The rear does not have a drain plug so you have to suck the old fluid out of the fill hole. I filled until overflow and that was around ~1L.

No fancy reset procedure or anything like that

[dreamspeed]

One more thing, i've read on several posts that you need a low profile 14mm hex to get to the fill plug in the front diff.

This is inaccurate. I actually have a low profile 14mm hex and was able to get it into the drain plug with a ratchet but there is zero room to move the ratchet afterwards. I literally had zero space to swing the ratchet.

There's actually an opening near the drain hole area you can snake an extension through.

It was very easy to use a ratchet + 6" extension to get to the drain plug.

[PDM5]

Did you find any DIY instructions (beyond the one BMW TIS) or did you just wing it? I'll be looking to do diff, transfer case, and tranny fluids soon as I've got 98k on the clock. If so, do you mind sharing?

[dreamspeed]

Originally Posted by PDM5

Did you find any DIY instructions (beyond the one BMW TIS) or did you just wing it? I'll be looking to do diff, transfer case, and tranny fluids soon as I've got 98k on the clock. If so, do you mind sharing?

I just changed the front and rear diff and I only had the TIS instructions.

You don't need more instructions than that. For the front it's a 14mm hex for the drain and fill. Just drain and then fill until overflow. The instructions say to only fill 600ml and that's what I did and it still overflowed. BMW TIS says the capacity is 600ml.... so I'm not sure why the special instructions.

For the rear there is no drain plug, you gotta suck the fluid out from the drain and then refill until overflow. The real capacity is ~1L

All bolts are ~44lb ft torque spec.

[PDM5]

Originally Posted by dreamspeed

I just changed the front and rear diff and I only had the TIS instructions.

You don't need more instructions than that. For the front it's a 14mm hex for the drain and fill. Just drain and then fill until overflow. The instructions say to only fill 600ml and that's what I did and it still overflowed. BMW TIS says the capacity is 600ml.... so I'm not sure why the special instructions.

For the rear there is no drain plug, you gotta suck the fluid out from the drain and then refill until overflow. The real capacity is ~1L

All bolts are ~44lb ft torque spec.

Great thanks!