DIY: Do It Yourself
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|04-08-2012, 10:46 PM||#1|
Suspension overhaul: diagnosis, parts selection, DIYs, torque values, links and tips
I am definitely an amateur mechanic and I would do extensive reading on these subjects beyond this post. As some e46Fanatics would say, when you've read to the point you feel like you're going to puke, you understand what you need to know. My previous experience includes a little bit of work on a Ford Taurus and on my current car: VANOS, oil filter housing gasket, water pump, and rear brake pads.
I never really found a single, comprehensive post on new suspensions that included all the "little parts," all the DIYs you need, and research/reviews for all the required new parts. I tried to do that here and be as comprehensive as possible.
I wrote this to the level of even the most amateur of mechanics, but the torque values, part numbers, new part research/reviews, and a couple other things may be useful to more experienced e46Fanatics.
I have a 2005 e46 330Ci ZHP with 62k mi and 20k are from me. In terms of suspension, a ZHP has a few minor differences, which are noted here and in the other sections:
Metal inner front control ball joints
Slightly thicker sway bars
Sport shock/coils/struts, which many non-ZHPs also have
This post should be useful to you no matter which e46 model you have.
Generally speaking, the suspension components work together to smooth out your ride, maintain smooth travel of the wheels up and down, maintain alignment, minimize body role and minimize noise. Since the suspension is constantly moving while the car is in motion, you'll notice that almost all the metal components are mated together via a metal-rubber-metal combination of components. The rubber prevents noise and significantly affects the smoothness of the ride. (Racers and enthusiasts replace many of these rubber components with metal or polyurethane aftermarket parts, which are stiffer but offer greater responsiveness via less flex.
Lots of great suspension info here: http://farnorthracing.com/autocross_secrets6.html
Huge thanks to many e46Fanatics, who I have tried to give credit where credit is due, and also ModBargains.com (Gilbert), bimmerworld.com (Bryan), PowerFlexUSA.com and oembimmerparts.com. Gilbert was especially helpful and answered many emails and phone calls for even the dumbest questions. Also, thank you to Silver Spring (formerly Tischer) BMW just north of DC. $60 for all new nuts and bolts is a really good deal compared to the $130 I was looking at from other dealerships around here. They do not quite fit the 'stealership' stereotype given to most dealerships. You can order discounted parts from them online, too (see link below.) Thanks to everyone listed here, I saved a ton of money and was able to come up w/the right combination of OEM and aftermarket parts for longevity, performance, and ride comfort.
Before trying to diagnose and DIY, it's important to understand where you're starting from, i.e. the stock OEM e46 suspension.
The stock OEM e46 suspension components
FRONT e46 suspension components
Front only. This is a shock/coil spring combo assembled as a single unit. They can be assembled by the manufacturer (e.g. BMW or a H&R Cup Kit) or they can be assembled by the home mechanic/dealer/independent shop if the shocks and coil springs were purchased independently of each other, e.g. Koni FSD shocks combined with H&R coils.
Front Control Arms (FCA)
These affect alignment and act as a guide when your wheels move up and down over bumps in the road. They contain an inner ball joint, an outer ball joint, and a Front Control Arm Bushing (FCAB). The inner ball joint typically needs replacement anywhere from 30k-100k, although inner ball joints on ZHPs are part metal and tend to last longer.
See #5: http://www.realoem.com/bmw/showparts...53&hg=31&fg=05
Front Control Arm Bushing (FCAB)
The FCAB is oil filled and almost guaranteed to go bad between 30k and 75k (mine went at 61k). When these go bad, things are worse than ever.
Rubber part inside of #6 (not labeled with a number): http://www.realoem.com/bmw/showparts...53&hg=31&fg=05
In this diagram, #1: http://store.powerflexusa.com/bmw-e4...ings-p112.aspx
This is the metal housing for the FCAB and it joins the FCAB to the car's frame.
See #6: http://www.realoem.com/bmw/showparts...53&hg=31&fg=05
The sway bar helps prevent body roll when turning. An upgraded sway bar typically results in less body roll, and these very much affect understeer and oversteer so figure out what you're doing if you upgrade. I didn't upgrade because I didn't want to change the factory understeer/oversteer...yet.
See #1: http://www.realoem.com/bmw/showparts...17&hg=31&fg=10
Stabilizer/Sway Bar Mounts
These are the polymer (rubber) attachment points for the sway bar to the Frame.
See #2: http://www.realoem.com/bmw/showparts...17&hg=31&fg=10
See #2: http://store.powerflexusa.com/bmw-e4...ings-p112.aspx
Sway Bar Linkage/End Links/Swing Supports
These attach the sway bar to the front struts.
See #5: http://www.realoem.com/bmw/showparts...17&hg=31&fg=10
These are rubber and mate the bottom of the coil spring to the shock and the top of the coil spring to the spring plate/perch (#7).
See #11 and #8: http://www.realoem.com/bmw/showparts...08&hg=31&fg=10
These are the metal (rigid) support that are used to hold the compressed coil spring to the top of the shock. They have a bearing that allows the strut to swivel and prevents torquing of the strut during turning.
See #7: http://www.realoem.com/bmw/showparts...08&hg=31&fg=10
Inner/Outer Tie Rods
This is a steering component that is commonly replaced with the suspension components listed here. Tie rods are linked to the steering column/steering wheel and push the steering knuckles (and wheels) left and right. The end of the outer tie rod has a rubber joint that tends to go bad. The inner tie rod has a ball joint. It's made entirely of metal, but most people replace both inner and outer tie rods because by the time you replace the out tie rod joint or any of the suspension parts listed here, your inner tie rod will have taken a significant amount of wear and tear, too. Since new tie rods and suspension require an alignment ($180-$270 at the dealer), many people replace their tie rods while doing all this other work. If you don't replace the tie rods and they fail soon after replacing the suspension, you'll have to pay for another alignment. I bit the bullet because knowing the typical OEM rubber fittings, they probably aren't going to last a whole lot longer. If you have someone else do your work, it's also a lot cheaper to have them replace the tie rods if they're already working on the suspension.
See #4 and #10: http://www.realoem.com/bmw/showparts...40&hg=32&fg=25
REAR e46 suspension components
Located separate from the coil springs in the rear of the car. These provide damping, i.e. prevents your car from bouncing after the initial compression of the coil spring over a bump. Without these, your car would look like an old Buick that bounces down the road.
See #1: http://www.realoem.com/bmw/showparts...25&hg=33&fg=45
Located separate from the shocks in the rear.
See part between #15 and #18: http://www.realoem.com/bmw/showparts...25&hg=33&fg=45
Rear shock mounts (RSM)
The rear shocks require a small rubber mount, gasket, and several washers to mount the top of the shock to the frame of the car. RSMs typically come with the gasket, washers, and any other parts needed for mounting the top of the shock to the frame.
See #6 through #14: http://www.realoem.com/bmw/showparts...25&hg=33&fg=45
I started looking into suspension problems in my e46 when the cornering just didn't feel as crisp as it did when I first got the car 20k ago (40k at the time). The car became much noisier over bumps. Some e46Fanatics claim to hear 'clunking' and others claim that the car doesn't maintain it's line well, particularly in windy or high speed conditions. I'm sure there are many other symptoms, but the bottom line is if you suspect suspension issues, they're probably starting to develop so do some of these inspections as they are very simple. Also, if you're not sure if your suspension is developing problems, you'll know it in another couple hundred miles by the way it drives - the handling will deteriorate rapidly. I'm not advising this over an inspection (by you or a mechanic), but that's basically what happened to me.
Related link about vulnerable e46 points from Stinger 9: http://forum.e46fanatics.com/showthread.php?t=896234
Begin with a bounce test. Look this up on Google - it's not the most reliable test, especially for an amateur mechanic, but if you have a real shock/strut/coil problem, you'll be able to tell. My rear end felt like the coil springs were shot and sagging too much (the appearance of the height of the car also confirmed this). I pushed down on the rear bumper and then stood in the trunk, pushing my weight down. I think I bottomed out the car pretty easily and it just didn't feel smooth/normal.
Also, you may be able to see hydraulic fluid running down the rear shocks (Google image this)...time for replacement.
And the most sure fire way of dianosing the shocks and springs is this. Before jacking up the rear, remove the rear shock mount bolts (inside the trunk - see DIYs below). Jack up the rear and remove the rear wheels. You can see if a spring is cracked or broke. Then, manually compress the shock. When I did this, the shock didn't spring back up...time for replacement. With the front wheels off (or just jack up the front to create some space), you can manually inspect the springs and look for hydraulic fluid leaks.
Front Control Arms (FCA) Ball Joints
I can't confirm this diagnosis method as I think my ball joints are still in good condition, but I read somewhere that if you jack the car up, grip the wheel at the 12 and 6 o'clock position, and shake hard, you'll be able to feel play when there should be no play whatsover. Many e46Fanatics seem to figure out that their ball joints were shot after removing their FCAs to replace the FCABs.
Front Control Arm Bushings (FCAB)
These are among the most failure prone e46 suspension components and worn FCABs will significantly affect corning, noise, and ride comfort. While your car is still raised from the FCA ball joint inspection, grip the wheel at the 9 and 3 o'clock position and shake hard. I actually heard 'clunking' and could see my front control arm shaking back and forth. Just imagine the wear and tear on the FCAB housing and bolts when you're driving down the road...time for replacement
Stabilizer/Sway Bar Mounts
Like all the other e46 suspension components, these go bad, too. See a trend? Excess wear is obvious from a visual inspection. The holes in the rubber where the bar passes through will be stretched out.
Sway Bar Linkage/End Links/Swing Supports
I think mine were fine, but I read that worn end links are obvious if you grab a hold of the end of the sway bar and shake hard. Then, try shaking the end links and feel for play, too.
Rear Trailing Arm Bushing (RTAB)
I never found diagnosis instructions for these but they're known to go bad between 30k and 40k.
I replaced all of the parts above with the exception of:
I think many on here would argue that I should just get new ones because it is the most bang for the buck component, you maximize the potential of upgraded shocks/coils/struts, and you can feel the difference in body roll when cornering. I hadn't done the research on understeer/oversteer yet and didn't want to spend anymore money at this point.
Spring pads and front spring perches
My suspension choice did not require these because they were a different design altogether. Many people reuse these if they fit.
Front strut mount
Like many people, I just reused these. Racers who want to adjust the camber use camber plates instead.
Front and Rear strut braces (not an OEM part)
Some e46Fanatics recommended these but I didn't buy them at the time of this writing.
Final parts list:
Struts (came with new, shorter sway links)
Front control arms
Front control arm bushing (FCAB)
Front tower reinforcement (because the stock frame is not designed to handle a stiffer/stronger-than-stock suspension)
Spring perches (because the stock frame is not designed to handle a stiffer/stronger than stock suspension)
Rear shock mounts (RSM)
Rear trailing arm bushing (RTAB)
Wheel spacers and hub extensions
Pics from Gilbert/ModBargains:
Spring perches http://www.rebmw.com/mm5/graphics/00.../rein1_300.jpg
What can happen without spring perches
What can happen without RSMs http://www.rogueengineering.com/mm5/...m_fail_300.jpg
Note: Turner Motorsport makes various reinforcement kits that are probably wise to install. They're custom metal plates that are designed to be welded to the existing frame.
There are a decent number of people out there who believe in the BMW design and would practically think it is a sin to put any non-OEM part on their car. As an engineer, I definitely appreciate the engineering and design work that goes into the Ultimate Driving Machine, but I just couldn't justify replacing parts that fail so soon with the exact same parts.
There are many options and opinions out there on the best e46 suspension parts. These decisions ultimately depend on your driving preferences, driving conditions, and location. Organized reviews of different setups can be found here (thanks FreeRide1645):
non-xi e46's http://forum.e46fanatics.com/showthr...192&highlight=
xi e46's (Not sure about the link - anyone else know this?)
The options seem to fall in several categories:
You know what they feel like and you know they were designed exactly for your model, but they don't last long enough and are pricey compared to other options with better performance.
At ~$650 from H&R, you get the same (or better?) performance than stock and some lowering.
There are many choices out there - the shocks I came across the most were Koni Yellows and Koni FSD. Eibach springs seem to be the most popular, although I was considering going with Yellows/OEM springs to maintain the stock ride height. UUC also had many good reviews, but I did not look into their setups. The combo route for good shocks and springs is going to run $800+ unless you get a deal.
This type of suspension was formerly available on race cars only. They offer the best combination of performance and ride quality, and start at $850 (www.bavauto.com). A common argument is why go with anything else when these are not much more expensive. They have adjustable ride height and the springs and shocks are perfectly tuned to match each other. I considered Suspension Techniques Variant 1 (ST V1) and Bilstein PSS, both around $1050.
These were my concerns and what led me to the ST V1s:
I was really just looking to gain the stock performance back, or better as long as I was replacing parts. I do not track my car and the ST V1s seemed to be one of the best coilovers for daily driving and spirited driving.
I didn't want to go much lower than the stock height. I also don't prefer the aggressive look with a lower front end - I wanted to stay level. I read somewhere that the ZHP package lowers the car by .75" (can anyone confirm?) from the stock e46 in the front and rear. According to http://www.bimmerfest.com/wiki/index...rmance_Package the ZSP package has the same springs so I assume the ZSP height is the same as the ZHP height. The ST V1s have adjustable height of 1.2"-2.8" in the front and 1.2"-2.0" in the rear. This equals .45" lower than stock at the highest height.
The consensus on this site and from Gilbert at ModBargains.com seemed to be that the ST V1s are more comfortable for daily driving than the Bilstein PSS', but have equivalent or better performance.
The ST V1s are the same as the KWs (and built by KW), but the ST V1s have some parts made of high grade galvanized steel while these same parts in the KWs are made of stainless steel. As a result, the ST V1s are $300-$400 cheaper. Gilbert said he wouldn't recommend the ST V1s to e46 owners in Canada and the northern states and that I would probably be OK here in DC/Northern VA. I was OK with the ST V1s knowing that I wash the undercarriage of my car regularly in the winter.
Front Control Arms (FCA), Front Control Arm Bushing (FCAB) and FCAB housing
Meyle HD appears is the gold standard for FCAs.
There is a lot of debate between PowerFlex polyurethane bushings, Meyle HD, and well, not many people go with the oil filled OEM bushing. They fail too quickly. Once all the oil leaks out, you're in for a choppy ride. Those who went with PowerFlex have a wide range of opinions, and some even went so far as to remove them soon after installing them. My main concern was sacrificing ride comfort. What I gathered is that the ride comfort for the passengers remains unchanged, but the feedback from the road is greater through the steering wheel.
I bought the FCAB pre-installed into the housing because as someone with limited experience doing all these jobs at once, I wanted to save myself a little time and effort.
Total cost: $440 including shipping from bimmerworld.com
These came with the new ST V1's - they're shorter than stockc.
Stabilizer/Sway Bar Mounts
I did not replace these at the time of this writing, but I plan to soon.
Meyle HD appears to be the gold standard. They're $130 with free shipping at oembimmerparts.com and they arrived in 2 days.
Rear Shock Mounts (RSM), Rear Spring Perches and Front Tower Reinforcment
I believe Gilbert at ModBargains.com steered me in the right direction for buying all the important extra parts beyond the ST V1s, i.e. spring perches, front tower reinforcement, and RSMs. The RSMs and spring perches he sent me are Rogue Engineering and the front tower reinforcement has a sticker that says 'BMW Group' so I assume they are OEM. See #13 here: http://www.realoem.com/bmw/showparts...08&hg=31&fg=10.
Rear Trailing Arm Bushings (RTAB)
It seems like most e46Fanatics go with PowerFlex or OEM M3 RCABs with spacers/limiters by Vorshlag (www.vorshlag.com). I went with the later for the reasons described on Vorshlag's website, which I verified at several other racing sites.
Nuts and bolts
Most manuals, including TIS, recommend that you replace all the nuts and bolts when doing any job on your car. Some of the nuts are lock nuts and should definitely be replaced. These were for my car and you should to double check the part numbers at realOEM.com for your model:
Wheel spacers and hub extension
After installing everything, I learned that my rims were rubbing . I went with 5mm H&R spacers and TMS hub extensions in the front and 12mm H&R spacers in the rear. I haven't received them in the mail so I can't comment on the look yet.
Info on wheel spacers and hub extensions: http://www.turnermotorsport.com/t-wh...yclopedia.aspx
Price: ~$250 but varies depending on brand and size
33306760652 Front control arm bushing housing bolts (4)
07119904295 Sway bar bushing support nuts (4)
31306779487 Bolts for attaching bottom of front struts to steering knuckle (2)
33306760587 Nuts for attaching sway bar support/linkage to front struts (2) (came with ST V1s)
31316769731 Nuts for attaching front strut mounts to frame (6)
33326760386 Bolts for attaching rear control arm bushing housing (6)
33326760389 Bolts for rear control arm bushings (2)
33326760668 Nuts for rear control arm bushings (2)
07119900402 Bolts for attaching rear shocks (2)
I bought the nuts/bolts from Silver Spring (formerly Tischer) BMW for $60. (Thanks, Tony!) MSRP is $130 so if your dealership charges you MSRP, Tischer is still a lot cheaper includiong shipping: http://www.trademotion.com/parts/?ac...2&make=&model=
Price for RSMs, rear spring perches, front tower reinforcement, and ST V1s: $1208.41
TOTAL PARTS COST: $2100
(Not including any sway bar parts or strut braces)
DIYs and other tips
Socket set going at least up to 19mm plus 21mm and 22mm sockets (21 is stock stut rod nut and 22 is aftermarket strut nut)
Torch if you have bad rust
Whatever you use to jack up your car - I use a floor jack, the OEM jack, floor stands, and 2x6's
RTAB specialty tool - rent one from an e46Fanatic (search: RTAB Tool) or buy one, e.g. http://www.mistools.net/shop/article...1%26aid%3D1%26
Pickle fork/ball joint separator for FCA ball joints (Note I used these tools and they did NOT work well: http://www.autozone.com/autozone/acc...questid=832135)
For FCABs, research DIYs if you're reusing your FCAs and installing new FCABs in their housings - this requires several special tools
Copper anti-seize compound (RTAB)
Hub grinder (sander) or sandpaper
Order of Work
1. Pre-work in the couple days before the installs.
2. Replace all parts except tie rods and RTABs
3. After car settles, replace tie rods and RTABs and then get an alignment immediately. Installing new tie rods and RTABs will alter the alignment more than any other parts and it's best not to drive around with bad alignment while the suspension is settling. These two parts do not need time to settle like the springs do.
On two different days while I was researching and waiting for parts, I used WD-40 to help loosen some bolts and the wheels. I sprayed all the bolt threads being careful not to spray any rubber pieces (although most of them were getting replaced***8230. Chemicals aren't good for them. I sprayed where the rims meet the rotors by poking the WD-40 tube between the rim spokes. I also took off the wheel caps to spray where the rims meet the rotors.
Wheels and wheel spacers
Per the TIS, be sure to keep the wheel holes lined up with the holes in the brake disks. Also, put the lug nuts back in their same holes. To do this, before jacking up the car, I aligned the tire stem so it's at the bottom (per the TIS). When removing the lug nuts, I noted which holes they were in with respect to the wheel. When reinstalling the wheel, I kept the stem at the bottom and spun the brake disks so the holes were lined up again. For my car, I knew where to position the brake disk because the pattern on the back of the rim was slightly different around the allen screw in the brake disc. The rust pattern allowed me to know how to line up the brake disc. Per the TIS, DO NOT put any chemicals (lube, oil, etc.) between the rim, brake discs, and spacers. DO apply a thin layer of grease exactly where the rim meets the hub, but not anywhere else on the rim. Also, when using the spacers, you'll want to get the surfaces of the rim and brake disc that meet perfectly smooth so the spacers fit flush to these surfaces - otherwise, you'll get wheel wobble. Use a drill and wheel hub grinder (I just used sandpaper) to get the rust off the rim and brake disc. The portions of the disc surfaces that had a lot of rust had to be sanded down quite a bit. Using my fingers, I was able to tell when the disc surface was smooth throughout. It's not the most technical, but it worked.
I'm not going to reinvent the wheel with DIYs.
Bilstein PSS9 install: http://www.my330i.com/mod10.php
From 5speedsteve: http://forum.e46fanatics.com/showthread.php?t=407443
I used this DIY the most, except I found that I didn't have to unscrew the nuts for the outer tie rod in order to remove the front struts.
Notes on the rear suspension DIY
I didn't need a spring compressor to install the new springs. Also, despite what some say, it's not hard to install the springs with the adjuster on top (per the instructions) instead of below, and then set the height. To do this, adjust the adjuster so the ride height is relatively low. Pull down on the brake/hub assembly and put the springs in. Again, with one hand, push down on the brake/hub assembly and with the other hand manually adjust the adjuster. Pushing down on the brake/axle assembly creates enough height in there that you can adjust the adjuster by hand.
There is some black insulation around both rear shock mounts. This stuff is extremely fragile and breaks apart very easily. I destroyed the first one by accident. On the second one, I used a knife to carefully cut a nice circle around the strut mount so then the insulation was in two pieces instead of a million. When I was done, I just duct taped the piece back on. Yes, the integrity was sacrificed a little, but it's a lot cleaner then shredding the insulation and probably a lot easier then actually removing it in one piece. If you try to remove them completely and in one piece, there's a lot of extra parts particularly around the battery side, and there's not a lot of room to work with anyway. It seemed like more hassle than it was worth.
Notes on the front suspension DIY
With the ST V1's (or KW V1's), the dimple at the bottom of the strut goes in the slot in the steering knuckle clamp. This keeps the strut positioned properly. The diameter of the strut increases slightly as you go up the strut. If you use a jack to jack up the steering knuckle up into the strut, the strut will naturally come to rest where it's supposed to in the steering knuckle.
Also, you have to figure out a way to tighten the 22mm nut on the top of the coilover because the strut shaft spins as you tighten the nut. I couldn't fit an open ended wrench on the nut because the strut swivel/mount was in the way. I ended up jamming a 7mm open end wrench between the nut and the swivel and using an allen wrench to turn the strut shaft. Maybe some people on here can weigh in on an easier way of doing this... I've read that using an impact gun in few, very short spurts works, but some say that it could damage the seals at the bottom of the piston rod. Others used something like a vice grip with a rag, but I don't know how safe this is for the piston rod.
FCA and FCAB DIYs (from the e46Fanatics DIY collection threads)
I was fairly concerned with how to know where to position the FCABs an the FCAs. The TIS has you measure a 290.9mm from the center of the inner ball joints to the edge of the FCAB housing, but this didn't make sense when I made the measurement on the Meyle FCA. This is possibly why a couple e46Fanatics' indy shops don't like these FCAs because they say that the dimensions of the Meyle FCAs are not the same as the OEM FCAs. Regardless...Bryan at Bimmerworld told me that once I install and tighten the FCAs/FCABs/FCAB housings, the FCABs will position themselves. This worked perfectly fine, and it makes sense when you consider the bushing design. The FCA fits fairly loosely on the FCAB.
The ball joints will need to be tightened at first with an allen wrench and open ended wrench. Once they're snug, you can tighten the nuts with a torque wrench and the ball joints won't spin. You can't get to the passenger side inner ball joint unless you have a crow's foot wrench and an elbow or something like that. I didn't bother with it.
Front Tower Reinforcement
These go on top of the strut swivel/mount and under the strut tower (in the wheel well)
Spring Perch Location (thanks Gilbert/Modbargains.com)
These came with good instructions, although you'll probably need a crow's foot wrench to apply the proper torque to the center nut at the top of the shock. I didn't bother.
Rear Trailing Arm Bushings (RTAB) and RTAB Vorshlag limiters
http://www.vorshlag.com/instructions.php (scroll down)
Pull the old RTABs out towards the outside of the car! The RTABS will not pull out of the trailing arm towards the drivetrain/differential. I found this out the hard way and broke an RTAB tool. I believe the diameter of the RTAB changes slightly, even though it looks the same throughout.
TIS: "To avoid damage to rack and to suspension mounting, move rack in as far as possible."
TIS torque values - FCA
FCA to steering knuckle nut: 65Nm/47.94lb-ft
FCA to frame/chassis nut: 90Nm/66.38lb-ft
FCAB housing bolts: 59Nm/43.52lb-ft
TIS torque values - Front Struts
Strut to steering knuckle bolt: 81Nm/59.74lb-ft
Three nuts that attach at the top of the strut tower: 34Nm/25 lb-ft
Sway link to strut: 65Nm/47.94
TIS torque values - Rear Shocks/Springs
Rear shock mount nuts (factory and Rogue Engineering): 28Nm/20.65lb-ft
Upper shock bolt (with Rogue Engineering mounts): 11lb-ft
Lower shock bolt: 100Nm/73.76lb-ft in "Normal Position"
TIS torque values - RTAB
Trailing arm to front bracket (bolt that goes through RTAB): 110Nm/81lb-ft
Trailing arm front bracket to body (3 bolts): 77Nm/57lb-ft
TIS torque values - Tie Rods
Tie rod to steering knuckle nut: 65Nm/47.94lb-ft
Tie rod to steering rack: 100+10Nm / 73.76+7.38lb-ft
Tie rod clamping nut (I believe this is the nut that is used to secure the length of the inner and outer tie rods?): 45Nm/33.19lb-ft
Spring settling and height adjustment
Wait until your suspension settles before getting an alignment. You'll know when the springs have stopped settling if you measure from the fender edge to the bottom of each rim (TIS) or center cap (ST V1 instructions) and these values stop changing.
For the front suspension, I jacked up one side and used the tool that came with the ST's to make adjustments with the wheel still attached. For the rear suspension, it was a PITA, but I raised one side slightly, removed the bottom shock bolt, raised the car higher, and then adjusted the spring adjuster as described above.
I'm still waiting for the wheel spacers to arrive so the car is out of commission for another few days. I probably won't push it until I get it aligned...reviews coming soon.
Last edited by astonmartini03; 04-23-2012 at 07:35 PM.
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|04-10-2012, 02:04 PM||#2|
Join Date: Nov 2009
Location: La Habra
My Ride: F82 M4
It's always awesome helping out another fellow E46 member! Can't wait to see pictures of how everything turned out.
Alan Wei | Alan@ModBargains.com | (714) 582-3330 ext. 8006
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|04-18-2012, 02:01 PM||#5|
Join Date: Apr 2012
Location: Atlanta, GA
My Ride: 2005 325i
This is incredible. Great job and thanks. I'm about to do some of this, now thinking of doing the whole smash as well. For $1,840 in parts you probably saved $5K or more by DIYing it. My dealership wants $900 just for the differential bushings.
|04-18-2012, 02:22 PM||#6|
Join Date: Jan 2009
Location: Greensboro NC
My Ride: 325it 5-speed
Great write up, five stars for you
|04-23-2012, 12:40 PM||#7|
Kimaamja - I forgot to include the price of wheel spacers, hub extensions, and bolts in that total so tack on another $250 to that $1840...
Also, in the 'stock e46 suspension' section in the original post, I forgot to include a bunch of bushings that are in the rear. When I started doing the rear springs/shocks, I noticed that at least one of them was shot. There are four on each side - #'s 2, 3, 6, and 14: http://www.realoem.com/bmw/showparts...40&hg=33&fg=30
I'm not planning on replacing them because they probably affect your suspension less than any of the above mentioned parts, and I'm generally tired of wrenching on her right now.
Overall, I really like the new setup. At slow speeds, the springs are softer than stock and above 30mph, their comfort is about equivalent to stock. The combination of new struts and FCABs provides a little more feedback through the steering wheel, but is no less comfortable for passengers. I didn't like this at first, but now that I'm used to it, I like it more. I'm experiencing less body roll around turns, and I haven't even installed the new sway bar bushings yet.
Aesthetics - I started out a little lower than I had hoped, but I really like the dropped look. ST says the V1's are .75" lower than stock and I currently have them at .5" lower than the max height in the front (total drop = 1.25") and roughly the same in the back. Somehow the car still has an agressive stance even though the wheel gap in the front is much greater. I'd like an equally dropped height all the way around and before I get an alignment later this week, I will probably raise the car so it doesn't look like the body is resting on the rear wheels. Even at the current height, it does not look aftermarkety at all. The wheel spacers (5mm/12mm) did no change the look very much, and the average person couldn't tell the difference.
I have one complaint or...something I'm not sure about. The ST V1's have two spring types in the front - a smaller set for small bumps and then the main, stiffer set. With the smaller spring set, you do get the added benefit of a comfy ride, but I would question how the entry and exits of corners compares to say...the Bilstein PSS'. The Bilsteins are equally stiff throughout. When entering corners with the ST V1's, I get a slight rocking of the car to the outside, which is the small spring set compressing completely, before I get firm cornering from the stiffer spring set. Notice the two spring sizes on the strut on the left: http://www.modbargains.com/ST-Suspen...0232-90233.htm
I haven't decided yet if I like this transition from the smaller springs to the larger springs when entering corners. If possible, I would recommend you drive an e46 with the suspensions you're considering before pulling the trigger. Don't get me wrong - I love the new ST V1's, but I do wonder if I would've been willing to sacrifice a little bit of ride comfort for potentially improved cornering with the Bilsteins.
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