[neilvan]

Just a knowledge thread to keep somewhere for reference:

X4 M40i Sway bars:
Front- 28mm tapering to 25mm
Rear- 22mm
(front # 31306874433/ rear #33506874434)

EDC/sport Sway Bars:
Front-27mm
Rear-20.5mm

Non sport:
Front-26mm
Fear-18.5mm

Problem however is bmw does not list a replacement bushing for the rear M40i(front is bonded to the bar already). Unless someone can source a number; Best solution is to take new bushings for either size and have it drilled out to 22mm.

[neilvan]

Front brakes: X5 calipers/brackets w/ X4 M40i rotors

X4 M40i uses the same calipers has many X5 models(E70/F15) + X6. Its a different design and has bigger piston diameter (60mm vs standard 57mm). The Brackets are X4 m40i specific but X4 M40i rotors share the exact same specs as some X5/X6 models (V8 and high load) with 348mm diameter and 30mm rotor width but just super minor different offset.

X4 M40i rotors with the X5 brackets have the correct offset for the F25/F26 chassis and bolt on without spacers (some have figured out earlier that X5 rotors + spacers also work) but the X4 rotors are actually cheaper and you don't have as large of a gap between the rotor and dust shield this way.

X4 M40i rotors have left and right part numbers(side specific for performance reasons), specific pad part number (different compound although aftermarket options list the X4 M40i under all equivalent X5/X6 models) and different dust shields (will bolt on and likely cooling reasons) however stock will work and cover the whole disk.

[neilvan]

Front control arms:

X4 M40i lower control arms are different than the rear of the F25/F26 line up; Longer and different angle of the ball joint. Basically for performance reasons and will add slightly more negative front camber: F25/F26 factory spec ~-0.3 deg to the M40i spec ~-1.0 deg.

This will basically had a bit more steering feel/response, better handing and actually better tire wear under semi-aggressive driving. I know its still an SUV but -1.0 is still quite a small bit of camber compared.

Part #: 31106873139 & 31106873140

[agent_orange]

Great info, thanks.

The X4 M40i also has the -30min camber correction hubs/carriers fitted as stock. 31216857413 & 31216857414. Not cheap though, and not easy to find used.
I didn't realise the lower arms were different too and thought the camber difference was all from the hubs.

[neilvan]

Originally Posted by agent_orange

Great info, thanks.

The X4 M40i also has the -30min camber correction hubs/carriers fitted as stock. 31216857413 & 31216857414. Not cheap though, and not easy to find used.
I didn't realise the lower arms were different too and thought the camber difference was all from the hubs.

The camber correction kunckles are an part option for the M40i and the regular F25/F26. That is just if after an accident or for some reason 1 side is out of spec; The true factory camber gain is from the lower arms.

But yes, it is an option if anyone wants to spend some series $$ on some more factory camber increase past the arms

[agent_orange]

Originally Posted by neilvan

The camber correction kunckles are an part option for the M40i and the regular F25/F26. That is just if after an accident or for some reason 1 side is out of spec; The true factory camber gain is from the lower arms.

But yes, it is an option if anyone wants to spend some series $$ on some more factory camber increase past the arms

Are you sure about that?
RealOEM seems to indicate that the correction carriers/knuckles, which yes are normally meant for 'correction' to normal camber spec, are series fitted to F26 M40i.
Also all M40i knuckles I've seen for sale on eBay in the USA or Europe where there are decent photos have the 413 and 414 numbers cast in.
I've been daydreaming about buying a used pair for years, but the cost with shipping to Australia makes it prohibitive as they are steel and normally come with hubs and arms.

I bought and installed brand new aluminium F8x correction carriers in my M2C, and they cost less than used F25/F26 ones do with shipping factored in.

I'm very interested in these M40i lower arms, as they are relatively low cost and easy to fit.
Have you measured the actual camber change from installing them?

You may also be interested in some of the suspension bushing and brake upgrades that I have done, search my posts.

[neilvan]

If you dig into real oem(at least my take away from it) is shows the 31216855953/31216855954 carriers as the standard for all the F25/F26 chassis(including the X4 M40i).

It also lists the 31216857413/31216857414 ones are the -30 camber correction option for all the F25/F26 chassis(including X4 M40i)

Whereas the F25/F26 chassis (this time excluding the X4 M40i) has the 31216857411/31216857412 option for +30 camber correction.


This is from the real oem under X4 M40i (notice how the 414 is called the swivel bearing)

Carrier, right 1 31216855954 +core
In the case of a repair, if camber
correction cannot be accomplished any
other way, it is done with a swivel
bearing.

Swivel bearing, camber correction, right -30MIN 1 31216857414
In the case of a repair, if camber
correction cannot be accomplished any
other way, it is done with a swivel
bearing.

[neilvan]

X4 M40i intake piping (or E70 X5) (not 100% confirmed just of yet)

Standard X3/X4
airbox side: 13717583714
Turbo size: 13717601177

X4 M40i
airbox side: 13717605585
Turbo side: 13718642279

Funny enough the Standard X3/X4 airbox side pipe is shared with the E70/E71 X5/X6 production up to 04/2012; where as the X4 M40i shares with the X5/X6 from 04/2012 onwards (and the F chassis X5/X6 + 6/7 series). The F10 5 series and hybrid options use a totally different upper/lower section to either(airbox section looks even more reduced than the pre 2012 X5 one and the lower one has no hose mounts on it).

All the hard ware and even the gasket mounting to all turbos are the same parts (only difference being the diameter/size in the middle where they connect to each other; end connection will all work as will all mounting points).

X5/X6 pre 04/2012
airbox side: 13717583714
Turbo size: 13717583715

X5/X6 post 04/2012
airbox side: 13717605585
Turbo side: 13717631699

While the X5/X6 shares the airbox side sections, the turbo section is different. They do however have the exact same shape and mounting points as the X3/X4 and X4 M40i respectively but there are some coolant hose that are slightly different; giving Bmw a need for a new part number ( the x5/x6 turbo section can be had used and cheaper than having to but the x4 m40i new). The X3/X4 one will have 3 hose clips(lower rad hose, coolant hose to the mickey mouse flange and the optional hose for the coolant/oil cooler); X5/X6 won't have the lower rad hose clip and the X4 M40i wont have the optional hose as it has the oil to air cooler only.

Pictures below show the difference in the airbox side pipes, the X3/X4 vs the X4 M40i turbo size and the cable mounting between the X3/X4 and the post 2012 X5 turbo size (notice how the X4M40i and the post 2012 X5/X6 also look removable).

[neilvan]

Some more digging and the Bmw 177 part (turbo side X3/X4) & the 715 part (turbo side X5 pre-2012) are the same casting just with the different coolant hose clamps on it. the X4 M40i, post 2012 X5/X6, F15/F16 X5/X6 and F series 640/740 all have the same casting just with different attachable coolant hose clips(not available separately sadly)

1st Picture below shows both part numbers cast onto the body(X3/X4 and the pre 2012 X5); 2nd picture show both the X4 M40i and post 2012 X5/X6 casting numbers match (part numbers were put on with stickers) and an F25 X3 N55 engine where in the lower left you can see all 3 hose clips being used and how

[How1978]

Originally Posted by neilvan

Front brakes: X5 calipers/brackets w/ X4 M40i rotors

X4 M40i uses the same calipers has many X5 models(E70/F15) + X6. Its a different design and has bigger piston diameter (60mm vs standard 57mm). The Brackets are X4 m40i specific but X4 M40i rotors share the exact same specs as some X5/X6 models (V8 and high load) with 348mm diameter and 30mm rotor width but just a slightly different offset.

X4 M40i rotors with the X5 brackets have the correct offset for the F25/F26 chassis and bolt on without spacers (some have figured out earlier that X5 rotors + spacers also work) but the X4 rotors are actually cheaper and you don't have as large of a gap between the rotor and dust shield this way.

X4 M40i rotors have left and right part numbers(side specific for performance reasons), specific pad part number (different compound although aftermarket options list the X4 M40i under all equivalent X5/X6 models) and different dust shields (will bolt on and likely cooling reasons) however stock will work and cover the whole disk.

Great post!

I already got the x4 m40i rotors from TRW:

BHS1063E (right side)
BHS1062E (left side)

x4 m40i disks from ATE:

24.0130-0250.1 (right side)
24.0130-0249.1 (left side)

I'm struggling to find the correct X5 bracket, do you happen to have the part # of it?

I see there are several x5 brackets for E70 and F15 available, I have no ideia which one has the fitting offset for the F25 chassis

[neilvan]

All of them will fit the rotor offset for the F25 calipers; you just need the correct ones to match the 348 rotor diameter of the m40i's.

Being in europe I believe you got more models and options (diesels and police packages etc) but the part numbers are : 34116778399 & 34116778400.

Over in North America they come on the V8+Diesel E70/ Diesel E70 LCI X5, N54 E71 X6 and Hybrid F15 X5 (Just find the ones that come with the 348x30 front rotors)

[How1978]

Originally Posted by neilvan

Being in europe I believe you got more models and options (diesels and police packages etc) but the part numbers are : 34116778399 & 34116778400.

Very appreciated.

Yep, I guess here in europe it is easier to find bmw parts, but not always they are cheaper than in the US, I usually get all my original bmw parts from leebmann24. Very reliable and fast shipping.

Parts 34116778399 & 34116778400 are over 260€ each

Due the price difference I'm inclined to get the original x4 m40i bracket/calliper carrier for 190€ ea. Part # 34116871419

Pads arrived today, ATE 13.0460-7231.2

[neilvan]

Why not buy them used? I bought low mileage calipers & brackets from the V8 E70 for $50 usd and they were super clean

[How1978]

Originally Posted by neilvan

Why not buy them used? I bought low mileage calipers & brackets from the V8 E70 for $50 usd and they were super clean

Calipers I could find them used, in good condition. Brackets unfortunately not

[bradsm87]

My interpretation of the parts catalogue is the same as that of agent_orange

The -30' part says "Series installation in F26 X4 M40iX". Also when you choose an M40iX on RealOEM, the +30 part is not listed, because the standard part on other F25/F26 vehicles is the +30 part for an M40iX. They're probably just limited by a fixed description per-part without being able to use a different name/description for the same part number for different vehicles.

Considering the alignment spec for the M40iX is -50' and for everything else is -20', exactly 30' different, the knuckle being the change makes sense.

The different ball joint angle on the arm is probably the only difference between the arms unless someone can accurately measure from centre of bush to centre of ball on both.

[neilvan]

Originally Posted by bradsm87

The different ball joint angle on the arm is probably the only difference between the arms unless someone can accurately measure from centre of bush to centre of ball on both.

Side by side the x4 M40i ones are longer. I didn't measure but it was noticeable by eye

[bradsm87]

Originally Posted by neilvan

Side by side the x4 M40i ones are longer. I didn't measure but it was noticeable by eye

It just doesn't add up when it comes to the wheel alignment spec and what RealOEM says with the knuckles.

I'd love to know for sure somehow because I'd much prefer to run a new genuine arm with a rubber bush rather than a squeaky-ass polyurethane bush with an offset shell that I'm about to install to offset the positive camber I got after lifting it.