M3 Steering rack Retrofit

[ShocknAwe]

Originally Posted by rbryantaz

Unless you have the M3 knuckles/brakes/struts/etc it the rack will need 135/335 inner tie rod. The tie rod connection is different on the M3 knuckle(upright) vs the x35i.
So I would just use the inner/outer tie rod from the original car.

I would however use the M3 steering shaft and coupler if your rack came with it.... I used the M3 parts on my 335i from the rack to the last steering wheel connection and was able to skip re-indexing the steering shaft, etc.

With my swap with the M3 knuckles, new control arms, m3 rack they didn't even change the alignment when I took it in and steering wheel was even centered (it turned out to be a waste of money to even align it). But that required changing to all of the M3 knuckles, brakes, struts, etc as I mentioned.

-Rich

I specified my build. To answer the question then, with M3 knuckles (full front conversion adding rack) do you use M3 tie rods or not?

My assumption is that with full M3 components the answer is yes unless the 1M uses different tie rods.

[houtan]

I have everything butthe rack so I am not an expert, but it is not clear what to use for the inner tie rods. I believe the outer tie rods are the same part so that doesn’t matter. The m3 inners are longer than the 135i.

When I do the install, my strategy will be that I will loosen the inner tie rods for my stock rack because it’s easier to loosen them while the rack is on the car. Then I’ll proceed to install the M3 rack with the M3 inner tie rod. If it works and I can get my toe in check then I’m good to go. If it doesn’t, the new rack is on the car and I can unscrew the inner tie rods and get my stock ones installed. Hopefully that makes sense.

[rbryantaz]

Originally Posted by houtan

I have everything butthe rack so I am not an expert, but it is not clear what to use for the inner tie rods. I believe the outer tie rods are the same part so that doesn’t matter. The m3 inners are longer than the 135i.

When I do the install, my strategy will be that I will loosen the inner tie rods for my stock rack because it’s easier to loosen them while the rack is on the car. Then I’ll proceed to install the M3 rack with the M3 inner tie rod. If it works and I can get my toe in check then I’m good to go. If it doesn’t, the new rack is on the car and I can unscrew the inner tie rods and get my stock ones installed. Hopefully that makes sense.

I did read it too quickly and missed that you had the M3 knuckles, my bad.

You can use the M3 tie rods if you have the M3 knuckles. The difference in the tie rods is definitely due to the knuckles!

My 335 has that same setup with everything M3.

-Rich

[ShocknAwe]

Originally Posted by houtan

I have everything butthe rack so I am not an expert, but it is not clear what to use for the inner tie rods. I believe the outer tie rods are the same part so that doesn’t matter. The m3 inners are longer than the 135i.

When I do the install, my strategy will be that I will loosen the inner tie rods for my stock rack because it’s easier to loosen them while the rack is on the car. Then I’ll proceed to install the M3 rack with the M3 inner tie rod. If it works and I can get my toe in check then I’m good to go. If it doesn’t, the new rack is on the car and I can unscrew the inner tie rods and get my stock ones installed. Hopefully that makes sense.

That was my plan but I like to avoid $130 repeat alignments if possible since while I can eyeball it I can't wrap my head around the tape and string method to DIY alignments.

Originally Posted by rbryantaz

I did read it too quickly and missed that you had the M3 knuckles, my bad.

You can use the M3 tie rods if you have the M3 knuckles. The difference in the tie rods is definitely due to the knuckles!

My 335 has that same setup with everything M3.

-Rich

Perfect. Was hoping someone had done it to confirm.
Massively appreciated Rich!

[houtan]

Sounds good. Looking forward to hearing how it goes.

[AshwinLB]

Originally Posted by houtan

I have everything butthe rack so I am not an expert, but it is not clear what to use for the inner tie rods. I believe the outer tie rods are the same part so that doesn’t matter. The m3 inners are longer than the 135i.

When I do the install, my strategy will be that I will loosen the inner tie rods for my stock rack because it’s easier to loosen them while the rack is on the car. Then I’ll proceed to install the M3 rack with the M3 inner tie rod. If it works and I can get my toe in check then I’m good to go. If it doesn’t, the new rack is on the car and I can unscrew the inner tie rods and get my stock ones installed. Hopefully that makes sense.

I used non-m inner tie rods with my non-m knuckles on my 135i. Outer tie rods are the same

[Jeb_]

So I bought an M3 rack without paying enough attention and it came without the servotronic "torque converter" solenoid. Can anyone confirm what the correct part number is? It's not listed on realOEM.

I think it might be 32-10-6-788-658. All the part sites show it as fitting on various models of pretty much every chassis code, but the M3 is never listed.

[WrathOTM]

Originally Posted by Jeb_

So I bought an M3 rack without paying enough attention and it came without the servotronic "torque converter" solenoid. Can anyone confirm what the correct part number is? It's not listed on realOEM.

I think it might be 32-10-6-788-658. All the part sites show it as fitting on various models of pretty much every chassis code, but the M3 is never listed.

You don't really need that little solenoid. If you are retrofitting this into a 128i you'll lack the little computer that would power it anyway. Unless you also plan on adding the JBBF module, just find a way to keep it covered and keep the dust out. Otherwise yes that looks like the right part number

[Jeb_]

Originally Posted by WrathOTM

You don't really need that little solenoid. If you are retrofitting this into a 128i you'll lack the little computer that would power it anyway. Unless you also plan on adding the JBBF module, just find a way to keep it covered and keep the dust out. Otherwise yes that looks like the right part number

Thanks for the confirmation.

I wasn't going to get it wired up, but isn't the solenoid (Or some machined plug) neccesary to keep fluid from spraying out?

[WrathOTM]

Ah, uhhh... Well sorry I can't say if it keeps fluid in or not. I guess I would try to fashion a plate to block it off that can be bolted on and lined with a gasket of some sort.

[Suprgnat]

Originally Posted by Jeb_

Thanks for the confirmation.

I wasn't going to get it wired up, but isn't the solenoid (Or some machined plug) neccesary to keep fluid from spraying out?

IIRC you are correct. You'll need something to restrain the PS fluid. My rack came with the solenoid so I just left it in place, unplugged.

[Jeb_]

10-4

I might take some measurements before I throw the solenoid on. From everything that's been posted, I don't expect the steering to be too heavy for my taste with the solenoid unplugged. However, with a new one being ~$300 and used ones always running a risk of leaking, being able to make a dummy plug with the correct O-ring groves might not be a bad idea. Could also play around with getting a fixed amount of resistance by sizing an orifice through it.

[houtan]

finished up this install recently and wanted to share a few things. thanks to bbnks2 and ShocknAwe for answering my pms.

the most valuable thing i can provide is accurate part numbers listed below. some of the part numbers I got from various threads were incorrect, such as the correct pins for the jbbf.

For the m3 tab, I decided to center the rack, remove the tab, and rotate it to match the position of the stock 135i rack, and reinstall the tab. The advantages going this route are no cutting necessary and when you reinstall the rack, you don’t have to worry about it being centered anymore because the tab is in place. Took maybe 10 minutes and it worked perfectly.

i have stock 135i hubs, m3 arms, running 3.8 degrees of camber, and the stock 135i inner tie rods worked great.

for coding, I added $216 to my vo, but still had to go into kombi and jbbf to change the settings below to aktiv. Not sure if updating the VO is worth it since you have to manually go and turn everything on in the end.

finally, to wire up the servotronic, the most important thing is for pin 1 on the rack connector to go to pin 5 on the jbbf, and pin 2 to go to pin 6.

the coding changes i had to do were:
KOMBI:
ST_MDRV_ALIVE_MONITOR
aktiv
ST_MDRV_CSUM_MONITOR
aktiv
ST_MDRV_ID_MONITOR
aktiv

JBBF:
SERVOTRONIC_VENTIL
aktiv

Parts you may need:
- Jbbf3, 9329800 or 9364819 (needs M on it)
- Servotronic Connector, 61129115546
- Pins, 61131393704, qty 2
- Pins with pigtails, 61130005199, Correct pin size but won't work for interior connectors because it includes rubber seal.
- banjo washer 14x18, 7119906464, qty 2
- banjo washer 16x20 (M3 part number), 7119906463, qty 2
- Banjo bolt M14, 32416781261, 22 ft lbs, 30NM
- Banjo bolt M16, 32416852470. 26 ft lbs, 35NM
- Nylon lock nut for outter tie rod to hub, 33306787062, qty 2, 122 ft lbs, 165NM
- Steering Rack mounting bolt, 32106773068, qty 2, 41 ft lbs +90 degrees, 56NM +90 degrees
- Nut for power steering rack bolts, 31356757707, qty 2
- Steering Shaft bolt for shaft to rack connection, 2306778609, qty 1, 18 ft lbs, 24NM
- Pentosin CHF 11 PS fluid 1L, 1405116
- Tie Rod Bellows/ Big hose clamp, 32106765232, qty 2, I ended up using breeze worm clamps instead
- Outter tie rod torx bolt, 30 ft lbs, 40NM
- Inner tie rod to rack, 81 if ZF/ 74 ft lbs if TRW, 110NM if ZF, 100NM if TRW

[ShocknAwe]

houtan fantastic.

Reminds me to follow up here, completed my install a while back, did same as above with the tab, lots of measuring, centered steering, cut tab and dremeled smooth and attached at zero without issue.

No servotronic here, steering heavy but can turn wheel with one finger, don't need it IMO. Worth noting my front end has 9.5/275 wheels/tires so already heavier.

Disclaimer is that my car is back up on stands as it has developed a serious popping from what seems to be the rack or arms when steering, vibrates up the column to the wheel without looseness. My suspicion at this point is that either the inner tie rods are bad, or the rack mount bolts are loose. Otherwise I guess could be the column u joint failing under the load of an unsupported steering assembly (no servo, now probably 10fold heavier steering than stock column supports) Nothing loose or broken in the suspension otherwise just went through everything. Update this evening hopefully. No leaks so saying a small prayer it's not the rack itself.

[houtan]

ShocknAwe , thanks.

Crossing my fingers it’s an easy fix for you. I dove without servotronic first and it was manageable. But with servotronic it’s glorious! Haha. I am just getting old and lazy, but worth it imo.

[ShocknAwe]

Originally Posted by houtan

ShocknAwe , thanks.

Crossing my fingers it’s an easy fix for you. I dove without servotronic first and it was manageable. But with servotronic it’s glorious! Haha. I am just getting old and lazy, but worth it imo.

Rack mount bolts were incredibly loose, also found a piece of trim believe it or not that was catching the tire. Totally silent on my test drive. Trim issue is another one of those annoying chase the noise until you find the semi-embarrasing cause.

Time to triple check the ride height and go in for an alignment.

[WrathOTM]

Does anyone know the part number for the JBBF module that has the servotronic capability or can we just code that in

[houtan]

Originally Posted by ShocknAwe

Rack mount bolts were incredibly loose, also found a piece of trim believe it or not that was catching the tire. Totally silent on my test drive. Trim issue is another one of those annoying chase the noise until you find the semi-embarrasing cause.

Time to triple check the ride height and go in for an alignment.

Well at least it was easy! You use new bolts and nuts?

[houtan]

Originally Posted by WrathOTM

Does anyone know the part number for the JBBF module that has the servotronic capability or can we just code that in

These are the part numbers I have saved that have the “M” stamp on it. You definitely need one with the stamp.

9329800, 9364819

[WrathOTM]

Gotcha, cool thanks

[ShocknAwe]

Originally Posted by houtan

Well at least it was easy! You use new bolts and nuts?

All around for sure

[bbnks2]

Originally Posted by houtan

for coding, I added $216 to my vo, but still had to go into kombi and jbbf to change the settings below to aktiv. Not sure if updating the VO is worth it since you have to manually go and turn everything on in the end.

modifying the VO is useful for future coding. With $216 in the VO your modules will always default to the "active" settings to make servo work.