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Discussion Starter #1 (Edited)
Introduction

This is a thread dedicated to info specific to the 3.6 VR6 & 4motion systems in the B6 Passat. Since picking up my 3.6 4motion wagon, I’ve found a ton of useful and interesting info through this forum. I thought it would be a good idea to create a thread to collect some of this info and hopefully add some more. These engines and drivetrains are different enough from the FWD turbo fours that I figured they deserved their own thread to collect all the great info people have shared here and elsewhere.

Note that this thread only covers systems that are unique to the 3.6/4motion cars. Things like interior & exterior mods, lighting, etc. will only be covered if they are something specific to the 3.6/4motion setup.

There's a similar thread in the CC forum dedicated to 3.6 CC owners--most of the content is a little old but it provides a nice complement to what we've got in the B6 forum:
CC .:VR6 Content Only:.

Thanks to all the forum members who have shared the threads that make this compilation possible. If you have any additions/corrections you’d like to see made, PM me so I can edit the thread accordingly.

Table of Contents

Engine & Electrical

Transmission / 4motion System

Intake & Exhaust

Suspension, Mounts, & Bushings

Brakes

Build Threads/General Ownership


edit 2014-02-19: Added link to similar thread in CC forum.
edit 2014-03-06: Renamed "Build Threads" section to "Build Threads/General Ownership" & added link to nater's 190,000mi update
edit 2014-12-23: Renamed "Suspension" to "Suspension, Mounts, & Bushings" and added info re: transmission mounts & bushings
edit 2015-12-14: Renamed "Engine" to "Engine & Electrical"
 

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Discussion Starter #2 (Edited)
Engine

ENGINE & ELECTRICAL
The V6 in the 2006-2008 US (2006-2010 in Canada) market B6 Passat is the 3.6L FSI VR6, engine code BLV. It uses the Bosch MED9 engine management system. In the rest of the world the B6 Passat was offered with a 3.2L version of this engine, with the 3.6 reserved for the high-performance R36 model.

Other versions of this engine have been used in the VW CC, Touareg 3, and US/Chinese B7 Passat; the Audi Q7; the Porsche Cayenne, and the VW Atlas.

While similar in concept to the port-injection 3.2 VR6 used in the MkV R32 and the 8P Audi A3, this engine uses a narrower angle between the cylinders (10.6 degrees) and direct injection, making the head, block, and intake manifold very different. Some accessories such as cold air intakes and exhaust components can be shared between the non-FSI 3.2 and the FSI 3.2 & 3.6.

This engine shares no major components with Audi’s 3.2 FSI V6, as found in the A4, A6, and Q5.

Technical information on the 3.2/3.6 FSI VR6 can be found in VW SSP 360.

Chips/Tunes
Since there are so few MED9 3.6 VR6s in the US, chip tuning options are limited. United Motorsports, APR, Unitronics, Revo and C2 have all offered programs. Whatever you choose, make sure that the provider of the tune has tested it on the car with the same model intake manifold that you have--the 3.6 in the B6 came with two (see the Intake section for more info).


Oil Pump Bolt
Some 3.6L VR6 FSI engines came from the factory with improperly installed bolts attaching the oil pump drive sprocket to the block. This bolt could back out, and since the sprocket is driven by the timing chain this could cause the chain to jump time and lead to severe engine damage.

This problem was corrected in the production line for late MY2007 cars and beyond, but if you have a 2006 or 2007 car with a 3.6L VR6 you should assume the bolt is bad and can back out at any time unless you have proof that it has been replaced. Replacement is not difficult but it is labor-intensive due to the bolt’s location. More information can be found in the Oil Pump Bolt Failure Thread.

Serpentine Belt Tensioner
The 3.6L VR6 uses the same serpentine/accessory belt tensioner as the 3.2L VR6 in the MkV R32/8P Audi A3. This tensioner is known to fail catastrophically by seizing up somewhat commonly in those cars. It has happened to a few B6 forum members but for whatever reason failure doesn’t seem to be as common on the 3.6. Still, it is something that should be inspected at every oil change by checking ease of movement of the tensioner’s roller and using a mechanic’s stethoscope to listen for bearing noise while the tensioner is spinning.

Note that the 3.6 has quite a bit of belt whine from the accessory drive under normal circumstances, and that this noise is not necessarily and indication that the tensioner is bad.

Thread with several experiences of tensioner failure and discussion of replacement
Videos of some failing tensioners in R32s
Replacement DIY from the MkV R32 Forum Note that you need a very short (less than 1.25") triple square bit to do the job in the 3.6 due to the location of the A/C hardline.

Startup Noise
The 3.6 can sometimes make a loud clattering noise for a second or two after a cold start. It appears that hearing this every once in a while, especially if the engine hasn't been started in several days, is normal. It seems to be caused by the hydraulic lifters, cam adjusters, and/or chain tensioners losing pressure as they sit, leading to noise as they re-pressurize. No damage to the engine has been found to be caused by this. However, if the sound persists for more than 5-10 seconds and happens more frequently, it may mean that one or more tensioners is no longer holding pressure and needs to be replaced or there is one or more bad lifter.

Battery
The battery is located in the trunk/hatch area on the driver's (left) rear side. The parts catalogs used by almost everyone in the US are wrong and specify the battery for the base model 2.0T for all B6 Passats. If you have a B6 3.6 4motion, you need a Group 49/size H8 battery rated for at least 760CCA and 92 amp-hours. OEM P/N for an AGM is 4F0 915 105 E or 000 915 105 E; standard lead-acid is 000 915 105 DK-DSP.

High Idle
Some owners experience an elevated idle speed (above 1000rpm), usually in hot weather conditions when the car is under high electrical loads. There is some variation in symptoms and circumstances, but in most cases the cause seems to be excessive electrical resistance, probably caused by a bad ground. A vacuum leak can cause similar symptoms, so both should be checked. More discussion can be found in this thread.

Some owners have replaced the Crank Position Sensor (G28) to solve this issue. User 4mo_jay has reported success with this approach.

MAINTENANCE

Timing Chain: VR6 Jedi master G60ING has put together a comprehensive thread dedicated to the timing chain system on the 3.6. If you think you hear timing chain noise, or are getting fuel system related codes that don’t make sense, or if you are just interested in learning more about how the 3.6 works, check out the thread.

Spark Plugs: OEM is usually easiest to find, but some people have had luck with NGK or Bosch,
0.36 gap and heat range 7

Oil: The 3.6 requires an oil compliant with VW 502. Mobil1 0w40 is 502 compliant and easy to find in most auto parts stores, or you can order any of these other oils online:
Audi USA's list of 502-compliant oils available in the US
An older list from the Oil and Lubrication Forum

Changing the oil is relatively simple. Here's a good post listing all the tools you'll need and some helpful tips.

PCV System: The PCV system is much simpler than in a forced-induction engine. There’s one valve, and while it rarely goes bad according to VW it can only be replaced as part of the valve cover. There is a trick to blocking off the system temporarily so you can still drive the car until you replace the valve. Fortunately a BMW tuning company has made a copy of the diaphragm and sells it in Europe for around US$50. You can also get it in the US from RKX Tech for around US$26. User dkarolj has replaced the diaphragm on his valve cover.

I did this on my own car, so I wrote up a DIY with pictures: DIY: Replacing the Intake Manifold Gaskets, Valve Cover Gasket, and PCV Oil Separator Diaphragm Valve in a 2008+ 3.6 VR6

Valve Cover Torque Specs

Intake Valve Cleaning: Like all direct-injection engines, in the VR6 FSI unburnt fuel builds up on the intake valves causing carbon deposits that can cause the car to run poorly. For whatever reason buildup happens much more slowly in this engine, but you should still plan on cleaning the valves once mileage gets past 100,000-120,000mi. To DIY you need to remove the intake manifold and it is helpful to get a media blaster and walnut shells to get the heaviest crud off.

Timing Chain Replacement: One thing to remember is that while the oil pump sprocket appears to be round, it is slightly elliptical and must be aligned correctly in order for the timing to be set properly.

This website has an excellent reference including special tools required, locations of timing marks, and torque values.

Head Gasket: User nater has put together an excellent DIY for 2008 cars with the two-piece manifold. 2007 is similar but removing the one piece manifold will add some extra work.
Head Gasket R&R and DIY 3.6L BLV 2008 Passat

Thermostat Housing (a.k.a. "Crack Pipe"): The thermostat housing is also a junction for 5 different coolant lines and resembles an implement for smoking a certain type of rock. As with older VR6 engines, it's made of plastic. While it isn't as failure-prone in the 3.6 as it was in older designs it can still, well, crack. If it does, or if you need to replace the thermostat, you can replace the housing with a cast aluminum version. More info, including part numbers for hoses and gaskets you should replace while you're at it, in this thread.

ENGINE REPLACEMENT

Forum member nater has had a long and unique experience owning a 2008 VR6 4motion since it was new. At 120,000mi he spun a main bearing and chose to replace only the bearing by dropping the oil pan. His conclusion at the time was that the bearing failure was due to low engine oil (and not the "dry start" problem which may not actually exist). His timing chains became progressively noisier and at 195,000mi he began getting intermittent "Low Oil Pressure/Turn Off Engine" warnings. It turns out one of the timing chain guides had disintegrated, clogged the oil intake, and caused the original bearing failure and subsequent problems. He chose to replace his engine with a remanufactured unit. The entire thread is worth reading for a detailed account of troubleshooting and recovering from catastrophic failure in the 3.6:
I spun a bearing...(now with pics!)

The 3.6 has been used in many different vehicles over the years, and while there are differences they are all pretty much physically compatible. User G60ING has made a list of things to look out for when swapping a newer 3.6 VR6 long block into an older 3.6 Passat or Touareg.

2014-03-17: added info regarding replacing the crank position sensor to fix the high idle problem
2014-03-30: added links to lists of VW 502-compliant oils for the US market, and to an oil change DIY
2014-09-09: added section on Nater's bearing failure/engine replacement
2015-07-02: added section on aligning the oil pump sprocket during timing chain replacement
2015-12-14: renamed section to "Engine & Electrical" and added information about the correct size for a replacement battery
2015-12-20: added link to nater' head gasket DIY
2016-02-25: clarified model year ranges for US and Canada
2016-05-09: added info on replacing the PCV diaphragm without having to replace the whole valve cover gasket.
2016-09-27: added link to US supplier for PCV diaphragm.
2016-12-08: added link to PCV diaphragm replacement DIY
2018-03-14: modified section on Startup Noise to include bad hydraulic valve lifters as being a potential cause
2018-08-17: added link to timing chain replacement reference.
2019-05-22: added section linking to G60ING’s timing chain resource thread.
2020-04-23: added info on the metal thermostat housing/"crack pipe" and swapping a newer 3.6 block into an older 3.6 Passat.
 

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Discussion Starter #3 (Edited)
Transmission / 4Motion System

TRANSMISSION / 4MOTION SYSTEM

Transmission
B6 VR6 Passats in North America were all equipped with the 09M 6-speed automatic transmission, manufactured for VW by Aisin-Warner. It is identical to the 09G used in 2.0T Passats except for a few modifications to deal with the VR6 engine’s extra torque.

For 2006-2008 cars VW stated that both the 09M and 09G had lifetime fluid and that the fluid and filter never needed to be changed. Starting in 2009 they went to a 40,000mi change interval, despite no changes to the hardware, software, or fluid and we are aware of. Due to this some believe that any VW with an 09M and 09G transmission should have its fluid and filter changed every 40,000mi, since the alternative could be a transmission rebuild.

The fluid/filter change procedure is the same for the 09M and 09G unit, although 4motion wagons use a different (larger) filter than FWD wagons and FWD & AWD sedans. An excellent DIY is posted on PassatWorld. A VAG-COM to monitor transmission fluid temperature is recommended but not required.

In Europe the DSG transmission was available on 4motion B6 cars as well. User bonestockglx installed a DSG unit from an Audi TT 3.2 in his car and documented it in this thread. In theory any manual transmission from another AWD/VR6 car will work too.

Final Drive/Power Takeoff Unit/PTU/Bevel Gear
The driveline component that would traditionally be called a Transfer Case in a 4WD vehicle is attached to the transaxle in 4motion cars, and the driveshaft to the Haldex Unit and Rear Differential comes out the back. Again, VW has no specified fluid change interval for the PTU. Most owners never change the fluid, but if you decide to make it part of your maintenance, Audi_Mechanic in the Mk V R32 forum has you covered:
Mini DIY: How to drain/fill bevel box, haldex and rear differential housing

4motion
AWD B6 Passats used a 2nd-Generation Haldex unit, similar to the one in the MkV R32, 8P Audi A3, and first generation (PQ35-based) Tiguan.

As with the transmission and PTU, VW does not specify a service interval for the Haldex unit or rear differential, but consensus on the MkV R32 forum seems to be that every 40,000mi is a good idea if you drive aggressively. Otherwise you may be able to get away with a longer interval. FWIW there are very few instances of Haldex unit failure on B6 Passats. Fortunately it is an easy DIY job, as long as you keep the drain and fill plugs for the Haldex unit and rear differential straight:
Haldex DIY
Rear Differential DIY

Neuspeed offers upgrade kits to replace the Haldex 2 unit with a street or race-tuned Haldex 4, with or without remotely-switchable programming.

2014-03-19: Added Rear Differential Fluid Change info
2016-01-18: Added DSG and Manual Transmission swap info
2016-02-11: Added PTU Fluid Change DIY
2018-03-29: Updated the sentence describing which other cars use the same Haldex system now that there are two generations of Tiguans.
 

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Discussion Starter #4 (Edited)
Intake & Exhaust

INTAKE & EXHAUST

Intakes
There are no cold air intakes made specifically for sale for the 3.6 in the US, but many made for the R32 such as the HPA Velocity will work. Here is a short video of a 1st-gear pull with the intake installed.

2006 and 2007 3.6s had a one-piece, variable length intake manifold that used a vacuum-actuated flapper to increase torque by reflecting the pressure wave from the intake valves closing back into the cylinder heads. In 2008 this was replaced by a two-piece fixed-length manifold that was less expensive to manufacture and to install while maintaining power levels. The R36 used the same two-piece manifold. The one-piece variable length manifolds are silver, and the two-piece fixed length manifolds are black.

Here are two DIYs for removing the intake manifold courtesy of nater:
Removing the One-piece (silver) Intake Manifold
Removing the Two-piece (black) Intake Manifold

It is possible to use a two-piece manifold in a 2008 car, as long as the ECU is re-coded to actuate the flapper:
https://forums.vwvortex.com/showthr...-my-Passat&p=80617097&viewfull=1#post80617097
https://forums.vwvortex.com/showthr...-my-Passat&p=84539186&viewfull=1#post84539186

Exhaust
The 3.6 has two exhaust manifolds, one for each cylinder bank. The two exhaust pipes join in a large resonator, a.k.a. the Suitcase, in the center of the car, before splitting again and passing through one more resonator per side before exiting through two exposed tips on either side of the rear valence.

In the US there are two catalytic converters per bank for a total of 4 due to the EPA’s more stringent NOx emissions limits. In the rest of the world, there is only one catalytic converter per bank. Since the O2 sensors after the second pair of catalytic converters are not monitored by the ECU (link goes to TSB 26 07 08 with details), US-spec 3.6s can be converted to use the two-cat setup by using R32-spec downpipes and cats.

One or more of the above components can be removed or replaced on the exhaust to change the sound or power response. Below are some examples:


There's a good thread in the 3.6 VR6 engine forum with a lot of info on exhaust options. Some of the info pertains to the American B7 Passat, but the principles are the same.

Bastuck makes a cat-back exhaust for B6-platform 3.2/3.6 4motion cars. It used to be only available in Europe, but some US suppliers are now importing it. Here's one thread showing the installation process along with some video clips of how it sounds in action, and another video of the Bastuck on a 3.6 4motion CC (same under the skin as our cars) with accompanying build thread.

Replacement Exhaust tips: MagnaFlow 35121 Stainless Angled Double-Wall Tips

edits: 2014-03-29: Added link to thread in the 3.6 engine forum
2015-05-18: Corrected error in intake manifold section and added info on identifying manifold types by finish.
2015-07-02, 2015-07-06: Added info on Bastuck cat-back exhaust
2016-07-26: Added nater's DIYs for removing the two types of intake manifolds.
2017-11-14: Removed some dead video links.
 

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Discussion Starter #5 (Edited)
SUSPENSION

Many items designed for the MkV R32 such as sway bars, front control arm bushings, and transmission mounts will fit the B6 Passat. However, the 3.6 is heavier than the 2.0T, and the 4motion system also adds weight in the rear. This means that 3.6/4motion owners shouldn’t assume that suspension components like coils, shocks, or springs that aren’t specifically designed for their cars will work. Here are some threads discussing our options:


Beware any springs, shocks, or coil overs that claim to work for both wagons & sedans, 4motion and FWD--they will most likely ride too low in the back and in the worst case the rear springs or shocks could fail.

Here is a shopping list of parts for replacing front CV joints, ball joints, tie rods, and struts.

MOUNTS & BUSHINGS

User nater has successfully installed the VF-E poly transmission mount for MkV Jettas/Golfs on his 2008 wagon with good initial results. He's tracking his experience in this thread.

The rear engine mount (a.k.a. pendulum mount a.k.a. dog bone mount) is similar to the one for 4-cylinder B6 cars and MkV-based cars, except that like the TT-RS and Tiguan 4motion it uses a larger front bushing and mounting bolt. User DBVeeDB has posted photos with dimensions in this thread (scroll past the breakfast photos).

edit 2014-12-23: Added information about transmission mounts and bushings.
edit 2018-03-14: Added link to front end rebuild parts list.
 

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Discussion Starter #6 (Edited)
Brakes

BRAKES

To deal with the extra weight, 3.6 4motion cars come with the same big brakes as the MkV R32: 345x30mm vented rotors in the front and 310x22mm vented rotors in the rear. Aside from excessive brake dust the stock setup is excellent. The only downside is that 17 wheels are the smallest that will clear the rear calipers.

3.6 FWD cars use the same brakes as 2.0T-equipped cars.

Here's a good discussion on aftermarket brake options for 4motion cars.

Like all B6 Passats, the rear parking brake is electronic.
 

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Discussion Starter #7 (Edited)
Build Threads/General Ownership

BUILD THREADS/GENERAL OWNERSHIP

How much does X weigh?
A question that comes up around here every so often is some variation on "how much more does A weigh than B?", like "how much does 4motion add to the weight of the car" or "how much heavier is a wagon than a sedan?"

Well, using Cars.com's handy comparison tool I compared the weights of 2008 models with comparable levels of trim and equipment (2.0T Lux, 3.6 FWD, and 3.6 4motion) and ran the numbers.

Here are the results, with the weights rounded to the nearest 10 pounds:

  • Wagons are 130 lbs heavier than sedans
  • A car with the 3.6 is 200lbs heavier than a car with the 2.0T*
  • 4motion adds 250lbs to the weight of the car*
* Note that since these are calculated using the VW-provided Curb Weight you can't use this to say that the 3.6 engine is 200lbs heavier than the 2.0T engine or that the 4motion system weighs 250 lbs. The weight increase includes all and any additional structure, heavier-duty suspension components, larger brakes, beefier transmission, etc. There is also some additional weight from items that were optional on the 2.0T Lux and 3.6 FWD cars and standard on the 3.6 4motion cars (Dynaudio, 18" wheels, AFS), but this should be good enough for settling arguments at the bar :)

------------------------------------------------------------------------------------------

The information in this thread would not be available without the hard work of these people, among others. There’s lots of great inspiration and discussion in these and others:

Build Threads
DBVeeDB: http://forums.vwvortex.com/showthread.php?5502094-I-m-Devin-this-is-my-Passat/
Shtbox: http://forums.vwvortex.com/showthread.php?6020759-Shtbox-s-3-6-4motion-Wagon
Aonarch: http://forums.vwvortex.com/showthread.php?6042752-Aonarch-s-Swaggin-Wagon
MDAce15: http://forums.vwvortex.com/showthread.php?5594106-The-story-of-MDAce15-s-B6-Passat-3-6-4Motion-Wagon
[email protected]: http://forums.vwvortex.com/showthread.php?5967165-My-arctic-blue-3-6-4motion-wagon

General Ownership
nater's list of repairs done over 7 years/189,000mi of ownership since new

Trailer Hitch Options
Finding a hitch that fits the 3.6 4motion cars typically either means getting one fabricated from scratch or ordering one from Europe or Canada. User carangeljr reports that the SRG 15048MT hitch and Tow Ready 118530 wiring harness work. More information can be found in this thread: Passat B6 VR6 4motion Wagon Hitch or Tow Mount

edit 2016-08-17: Added Trailer Hitch Information
edit 2017-03-13: Weight Information
 

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BRAKES


To deal with the extra weight, 3.6 4motion cars come with big brakes: 345x30mm vented rotors in the front and 310x22mm vented rotors in the rear. Aside from excessive brake dust the stock setup is excellent. The only downside is that 17wheels are the smallest that will clear the rear calipers.
Thanks for creating this thread! Just one question: Are the rear brakes vented or solid? I thought they were solid (whick might explain the relative lack of brake dust there versus the fronts in the rear-biased setup).
 

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Discussion Starter #12
Just wanted to note that my car still had the center resonator and rear mufflers, I had only deleted everything on the downpipe. I'll try to get a new video uploaded with the Vibrant cats and Ultra Quiet resonator welded in.

Great idea to put this all in one thread though. :thumbup:
Thanks, I'll update the post accordingly!
 

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Discussion Starter #13
Thanks for creating this thread! Just one question: Are the rear brakes vented or solid? I thought they were solid (whick might explain the relative lack of brake dust there versus the fronts in the rear-biased setup).
Rears are vented on 4motion cars, solid on FWD. 3.6 FWD cars have the same brakes as 2.0T FWD cars.
 

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This is a great idea, awesome composition!

Couple things to add:

Mk5 R32 brakes are the exact same as 3.6 4 motions, excluding the EPB. So pads/rotors that fit R32s will fit our cars.

R32 sway bars also are compatible with our cars. It seems as if you need something relating to suspension (unless it's springs/coilovers for the wagon rear) R32 parts will work as well.

I should really update the coilovers thread with this info but...got a wagon? If you find a set of used KWs or HPA SHS' for a good price that are for an R32, KW will sell a set of rear coilover springs. They are not cheap, ~$225 + shipping from across the pond. But the option is there. That is the only difference between a KW/HPA wagon coilover set. Rear shocks are the same. A cheap set pops up from time to time, so it can be cost effective if you get the original kit for a really good price.

Or, if you're in a position like me and don't want to shell out the cash quite yet, pick up a pair of mk5 FK/Solowerks rear perches. It will let you adjust the rear much higher, and the perches are not very expensive Nater has thrown caution to utilizing R32 rear springs as he had a rear spring snap. So use this method at your own risk.
 

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Discussion Starter #17
Couple things to add:

Mk5 R32 brakes are the exact same as 3.6 4 motions, excluding the EPB. So pads/rotors that fit R32s will fit our cars.

R32 sway bars also are compatible with our cars. It seems as if you need something relating to suspension (unless it's springs/coilovers for the wagon rear) R32 parts will work as well.
Quite right! I'll update the post.

Good point too on only using coils/shocks/springs that are designed for the 4motion wagons on those cars--the extra weight makes a big difference!
 

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Wow this is perfect! Just picked up my 3.6 4Motion and will be reading this religiously.
 

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Discussion Starter #19 (Edited)
Just checking something before I add it to the Suspension section: based on my research the stock front sway bar for 3.6 B6 Passats was 23mm in diameter, and the rear was 21mm for the normal suspension and 21.7mm for sport. Anyone find anything different from that?

edit: Now I'm thinking that the 3.6 got 23mm front/21mm rear stock, and 23.6mm front/21.7mm rear sport. Guess I could go measure mine but it's cold! :D
 
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