Passat or CC aluminum steering knuckles and LCA to save weight

[PRY4SNO]

Read an article the other day that suggests we can bolt on aluminum steering knuckles and LCAs from a CC or Passat. This would benefit our cars by reducing mass, lowering centre of gravity and increasing rigidity.

Asking around a bit it would seem the only potential problem could be introducing an offset issue. The article made no mention of this so I'm wondering what you guys think?

What exact year range would this be for compatible parts? 2006-2017 is what it says in a pic in the article, is that common between the CC and Passat?

How I Cut My GTI's Weight Where It Matters Most: Unsprung and Rotational Mass

Simplify and add big brakes.

www.thedrive.com

 

[Wilkins]

This is a mod I’ve been researching. What I read is that the cast steel knuckles are prone to bending when subjected to extreme loads. The cast aluminum knuckles are stronger and identical except that the offset to the tie rod connection is slightly less. This results in slightly faster steering response, ie the front wheels turn a bit more for a given steering wheel angle. As a result an alignment is needed after fitting- no kidding LOL.
The knuckles from a CC, B6 Passat, or mk6 GTI are aluminum. An NMS Passat is quite different and won’t work. The brake carrier mounting bolts also have to be replaced since the aluminum knuckle is thicker.
The reason I’m interested is my alignment won’t come into spec left front, and I suspect the knuckle is bent as a result of sliding into a curb some years ago.

 

[PRY4SNO]

Interesting, and good info, thanks. Especially about the brake carrier bolts.

The article's author was upgrading a mk6 GTI so I don't know about that particular platform having aluminum steering knuckles.

 

[JELLOWSUBMARINE]

Has anyone here done this major weight reduction? I wonder how much it would effect mpg?

Rotating unstrung vrs unstrung.

I wonder if somehow there is a sweet spot, like when lightning flywheel, too light can have some effects on things you might not expect,

 

[PRY4SNO]

@JELLOWSUBMARINE The mpg would be a tertiary benefit and quite minimal. There's more than a 10kg difference in fuel load during the course of a full to empty tank of diesel. The main benefit would be handling characteristics and then secondary would be less wear and tear on consumables.

 

[Wilkins]

Here is the link to the big thread on Golf Mk6 about this
Golf Mk6 Aluminum Knuckles

 

[PRY4SNO]

Here is the link to the big thread on Golf Mk6 about this
Golf Mk6 Aluminum Knuckles

That was a good read, thanks for posting.

 

[JELLOWSUBMARINE]

At first abit counterintuitive how the TT spindles aren't as quick as the s3/passat. but it makes sense as it was designed for a wider car. My son just did the front wheel bearings on his outback. He was amazed at how ez it was with his new bearing press kit. Maybe I can talk him into swapping the JSW What roughly does a set of s3 arms & knuckles go for $?

 

[PRY4SNO]

@JELLOWSUBMARINE From my searches on car-part.com it looks like they've gone up since the early days (gauging by that thread @Wilkins linked). That may be a domestic thing up here though. Most stuff is cheaper in the US.

 

[oilhammer]

I doubt you'd notice any difference in fuel economy.

 

[PRY4SNO]

I doubt you'd notice any difference in fuel economy.

Pretty much zero chance.

What's your take on installing CC knuckles and LCAs? Any potential issues with offset or things to keep in mind other than as noted above with longer caliper bolts? Other parts worthwhile to swap at the same time?

 

[oilhammer]

I have done similar things on other VAG products. I think the only reason I would mess with doing so is if it netted BIGGER brakes at the same time.

 

[Tharkhold]

I've done the conversion on both the front and rear. Gas mileage difference? Nil, or quasi nil.

Lighter/quicker driving/steering: yes, but it's NOT earth shattering.

I also have the Boxster 986 front calipers on mine along with 2-piece rotors as well, so I save another 3-6lbs per front corner.

Bottom line: is it worth it? If you can get the knucles at a u-pick yard for 15-30$ each? Yes. Don't forget that you WILL need different mounting bolts as the Al parts are thicker and you will need longer bolts for things like the knuckle to strut link.

Stats: Rear knuckles will lose 3lbs per side, front LCA and knucles will lose approx 8lbs per side, total of 24lbs.

If you need any hardware from the dealer, just state that the parts are for a 2008 passat/2012 tiguan FWD. If they insist, you can find a VIN online as well.

Bonus: Aluminium oxidizes alot slower than iron/steel... and it looks nice when new/shiny
Bonus number 2: the rear knucles will push your wheels out by approx 8mm per side.
Bonus number 3: if you use the passat/tiguan front lower control arm-to frame bushings, you'll lower the car by a few mm as well.

Not-so-bonus: you won't be able to mount 17LE/17z/18z porshe calipers on the front with Aluminium knuckles.

Nice and shiny-ish

 

[Tharkhold]

Here are a few parts for the conversion (some of these are the same parts as Iron/Steel, but since you're changing most of the parts, might as well get new ones):

Front list 3C0407253F Left Aluminium Knuckle Passat 2008 3C0407365B Left ball joint Passat 2008 3 x Nuts-to-LCA per side (N10332002) 1K0423811K Left Tie Rod Passat 2008 or Tiguan 3C0407254F Right Aluminium Knuckle Passat 2008 3C0407366B Right Ball Joint Passat 2008 3 x Nuts-to-LCA per side (N10332002) 1K0423812K Right Tie Rod Passat 2008 or Tiguan 3C0407151G Lower Control Arm (Aluminium L/R same) Passat 2008 2 x Bolts: N10560702, 1 x Bolt: N10640301 (per side) WHT000785 Nut, wide, ball joint to Aluminium knuckle Passat 2008 Single use, 1 per side 5K0498621 Front Wheel Bearing All need 2 WHT005437 Wheel Bearing to CV bolt, front All Need 1 per side WHT000237A Wheel Bearing to Knuckle mounting bolts All Need 4 per side N91168901 12pt Bolt, Apikol/carrier braket to Caliper Most single use, 2 per side REQ for 986 Conversion N90954802 BOLT. Strut. Mount. Shock. Passat 2008 single use, need 2 N10106402 Nut for above Passat 2008 single use, need 2 N10106402 x2 5Q0411315A Link. Stabilizer. All need 2 N90948802 Bolt, Caliper carrier to knuckle // Apikol to knucle REQ for 986 conversion Rear 3C0505433K Knuckle, Left CC/Eos/Passat/Tiguan FWD 3C0505434K Knuckle, Right CC/Eos/Passat/Tiguan FWD 1K0505465AA Link. Stabilizer. Bar. Suspension. All need 2 3G0598611A Rear Wheel bearing All need 2 N90648402 Bolt - Rear trailing arm bushing bracket to body All need 4 per side N90648402 x8 WHT000227 Arm. Bolt. CONTROL. Adjust. Cam. All need 2 N91201301 Bolt - Upper ctrl arm to rear bearing carrier All Al single use, need 2 N91201301 x2 N10401801 Nut - for Bolt - Upper ctrl arm to rear carrier All single use, need 2 N10401801 x2 N10628401 Bolt. Trailing. Arm. to rear carrier All single use, need 4 N10628401 x4 N10628601 Bolt. Arm. Mount. CONTROL. Rear single use, need 2 N10628601 x2 N10106402 NUT. Lock. Arm. Mount. Cntl. - Rear single use, need 2 N10106402 x2 N10211202 Hex Bolt - M12x1.5x90 single use, need 2 N10211202 x2 N91076701 Hex Bolt - M14x1.5x115 (Top of carrier) single use, need 2 N91076701 x2 WHT003467 Hex Bolt - Rear shock to carrier - M14x1.5x70 single use, need 2 WHT003467 x2 N91168901 12pt Bolt, Carrier to Knuckle single use, 2 per side WHT007150 Bearing to CV bolt, rear. All Need 1 per side

 

[Tharkhold]

Also,

when ordering parts like ball joints, ensure that they have the nuts for the aluminium parts.

The wide brimmed hat looking one installed on the below ball joint is the correct one for this application, the smaller nut is for steel knucles! Rockauto have some balljoints with both nuts, so order wisely.

 

[Tharkhold]

Save yourself some hassle... these are 60$ each on rockauto (SKP SK520470 and SK520469), and they come with the bushing and ball joint already installed (triple check the description as some are incorrectly listed as w/ and w/o balljoints):

(note: you will need to get 2 x wide-brimmed hat nuts (WHT000785) from a dealer as these come with the 'wrong' ones)

 

[mnb009]

Save yourself some hassle... these are 60$ each on rockauto (SKP SK520470 and SK520469), and they come with the bushing and ball joint already installed (triple check the description as some are incorrectly listed as w/ and w/o balljoints):

(note: you will need to get 2 x wide-brimmed hat nuts (WHT000785) from a dealer as these come with the 'wrong' ones)

Here are a few parts for the conversion (some of these are the same parts as Iron/Steel, but since you're changing most of the parts, might as well get new ones):

Front 3C0407253F Left Aluminium Knuckle Passat 2008 3C0407365B Left ball joint Passat 2008 3 x Nuts-to-LCA per side (N10332002) 1K0423811J Left Tie Rod Passat 2008 3C0407254F Right Aluminium Knuckle Passat 2008 3C0407366B Right Ball Joint Passat 2008 3 x Nuts-to-LCA per side (N10332002) 1K0423812J Right Tie Rod Passat 2008 3C0407151G Lower Control Arm (Aluminium L/R same) Passat 2008 2 x Bolts: N10560702, 1 x Bolt: N10640301 (per side) WHT000785 Nut, wide, ball joint to Aluminium knuckle Passat 2008 Single use, 1 per side 5K0498621 Front Wheel Bearing All need 2 WHT005437 Wheel Bearing to CV bolt, front All Need 1 per side WHT000237A Wheel Bearing to Knuckle mounting bolts All Need 4 per side N91168901 12pt Bolt, Apikol/carrier braket to Caliper Most single use, 2 per side REQ for 986 Conversion N90954802 BOLT. Strut. Mount. Shock. Passat 2008 single use, need 2 N10106402 Nut for above Passat 2008 single use, need 2 5Q0411315A Link. Stabilizer. All need 2 N90948802 Bolt, Caliper carrier to knuckle // Apikol to knucle REQ for 986 conversion Rear 3C0505433K Knuckle, Left CC/Eos/Passat/Tiguan FWD 3C0505434K Knuckle, Right CC/Eos/Passat/Tiguan FWD 1K0505465AA Link. Stabilizer. Bar. Suspension. All need 2 3G0598611A Rear Wheel bearing All need 2 N90648402 Bolt - Rear trailing arm bushing bracket to body All need 4 per side WHT000227 Arm. Bolt. CONTROL. Adjust. Cam. All need 2 N91201301 Bolt - Upper ctrl arm to rear bearing carrier All Al single use, need 2 N10401801 Nut - for Bolt - Upper ctrl arm to rear carrier All single use, need 2 N10628401 Bolt. Trailing. Arm. to rear carrier All single use, need 4 N10628601 Bolt. Arm. Mount. CONTROL. Rear single use, need 2 N10106402 NUT. Lock. Arm. Mount. Cntl. - Rear single use, need 2 N10211202 Hex Bolt - M12x1.5x90 single use, need 2 N91076701 Hex Bolt - M14x1.5x115 (Top of carrier) single use, need 2 WHT003467 Hex Bolt - Rear shock to carrier - M14x1.5x70 single use, need 2 N91168901 12pt Bolt, Carrier to Knuckle single use, 2 per side WHT007150 Bearing to CV bolt, rear. All Need 1 per side

Hey, I've got a mk6 Jetta and im planning on doing the Passat Subframe, LCA and knuckles. I had someone tell me that 986 calipers won't fit on knuckles. What did you do to get them to fit?

 

[mikerob97]

Had a question about this upgrade. I notice the above parts list includes the left and right tie rods. My question, are these require for the conversion? Thanks

 

[Tharkhold]

Hey, I've got a mk6 Jetta and im planning on doing the Passat Subframe, LCA and knuckles. I had someone tell me that 986 calipers won't fit on knuckles. What did you do to get them to fit?

Wut? I can GUARANTEE that the 986/boxster non-s calipers fit on Aluminium knuckles... I have them on right now. You need to get apikol adapters though, with the appropriate mounting bolts and banjo bolts (banjos/caliper bolts are an available option if you order apikol brackets). https://apikol.com/product/apikol-boxster-brake-brackets-a3-gti-rabbit-jetta/

The person might have been referring to the bigger brembo 17LE/17Z/18Z calipers found on Tuaregs/Cayennes, which unfortunately don't fit on the Aluminium pieces.

 

[Tharkhold]

Had a question about this upgrade. I notice the above parts list includes the left and right tie rods. My question, are these require for the conversion? Thanks

"Yes". The tie rod situation is a bit of a mess, as depending on where you look, these fit pretty much all VW's from 2005.5 to 2021. Now, on parts.vw.com the 'correct' tie rods that fit on passats and tiguans (i.e. Al knuckles) is 1K0423811K/821K. The J parts don't list the Tiguan nor do they list the 2008 Passat. Play it safe and get the K ones.

Side note: rockauto is messed up for these as well, ensure the parts you're getting are the K ones.

EDIT: I UPDATED THE ABOVE LIST AS WELL.

 

[Dalon]

This is a mod I’ve been researching. What I read is that the cast steel knuckles are prone to bending when subjected to extreme loads. The cast aluminum knuckles are stronger and identical except that the offset to the tie rod connection is slightly less. This results in slightly faster steering response, ie the front wheels turn a bit more for a given steering wheel angle. As a result an alignment is needed after fitting- no kidding LOL.
The knuckles from a CC, B6 Passat, or mk6 GTI are aluminum. An NMS Passat is quite different and won’t work. The brake carrier mounting bolts also have to be replaced since the aluminum knuckle is thicker.
The reason I’m interested is my alignment won’t come into spec left front, and I suspect the knuckle is bent as a result of sliding into a curb some years ago.

Do you know if the B7/MK6 jetta tie rods thread into the tie rod ends of the B6? I read Tharkholds list and he didn't list the tie rods, just the ends, so I'm assuming the tie rod ends of the B6 would thread into our B7/MK6 tie rods but wanted confirmation as I am acquiring all the parts for a full conversion.

 

[Wilkins]

I’ve done this conversion now, have to write it up. You don’t need to change the tie rod ends, just the nuts for both tie rods and ball joints.

 

[Tharkhold]

I’ve done this conversion now, have to write it up. You don’t need to change the tie rod ends, just the nuts for both tie rods and ball joints.

Aye, besides the obligatory nuts for Al parts, no. BUT as one is already taking all the suspension/steering bits apart for this conversion, and you NEED an alignment done afterwards, installing new parts just makes sense as everything is taken apart and within reach ($ allowing of course).

That and the fact that these new parts from rockauto are so cheap that it's worth it.

Edit: oh, and having new parts on hand allows you to go in 'fuk it' mode with a grinder just in case something is stubborn!

I'm looking at you F*%&$ING rear end links that have the ridiculous 6/12pt inner threaded stud that ALWAYS breaks off when trying to loosen the nut on these:

 

[Wilkins]

Yes I wasted 45 minutes before pulling out the zip cutter.

 

[squeaks]

Question for those that have done this, would the wheel bearings on the front knuckles need to be swapped over or would the bearings that came off of a 2007 Passat work for a 2013 Sportwagen TDI?

 

[Tharkhold]

Question for those that have done this, would the wheel bearings on the front knuckles need to be swapped over or would the bearings that came off of a 2007 Passat work for a 2013 Sportwagen TDI?

The front wheel bearings are pretty much all the same in the VWAG cars. They would work, however, you need to get a new axle bolt, along with the 4 bearing-to-knuckle bolts. You can't reuse them. Total for the front end swap are 2 x wheel bearing to axle bolts, and 8 x bearing to knucle bolts.

Bearings sold from rockauto optionnaly come with the axle and 4 x bolts fyi. I beleive FAG and WJB ones come with the hardware. The last pair i got were the WJB WA513253.

 

[Wilkins]

I swapped bearings but I’m quite sure that was unnecessary. Gave me a chance to clean up the knuckles nicely though. I now have a spare set of bearings from a 2006 Passat with unknown mileage and abuse.

 

[copenhagen]

Hi guys, did this conversion. Nice upgrade with the brakes as well. But now i have 20mm pr side where wheels sticks out on each side. What wheel speecs do u guys run to get them underneath the fenders? Im running Bilstein b12 suspension,

 

[Tharkhold]

I have 17" RPF-1's for summer and the OEM 17" wheels that came with the car for winter. I have to use 2mm spacers in the front to clear the RPF-1's, and 5mm spacers for the OEM wheels.

I don't have any fender clearance issues since the wheels i use aren't that wide. I'd love to go up to the 18x9' RPF-1's though... for that deep dish feeling! I'd probably have to roll the fenders/enlarge them though.

But on your issue, with the conversion done, your wheels poke out an extra 20mm? ...or are your wheels poking out from under the fenders by 20mm?

Reason i ask is that the front conversion 'shouldn't' add any extra track width, unless you mixed and matched some TTS/TTRS/Audi stuff (lower roll point/center of mass, lower ball joints (TTRS), scrub radius change *could* affect the car/alignment so that all these changes would impact the track width... but idk). The rear carriers add approx 8mm per side.

Maybe tell us exactly what you changes (with part numbers).

 

[copenhagen]

Hi, it’s not a problem on the front. Only on the rear. But it seems it’s a common issue since 3C0505433K and 434 it’s more likely 8 mm wider on each side.

but i cant figure out what wheelspecs i will have to run. I have 2 sets. Original Talladega 19 8x19 et 51
And 7.5x18 et 47 both of them sticks out approximately 20mm on each side.