NOTE: for those looking to find my final parts list, scroll down a bit through this first post.
I'm really new to suspension work and am a little overwhelmed with the loads of information and options available so I'm hoping someone can help me narrow down some things or at least point me in the right direction. Later this summer I plan to swap out my original shocks and struts for Koni Yellows (Sport). The original shocks and struts have only 50k miles on them but they've been on there for 10 years and it seems that a fair number of people believe that the original Sachs shocks/struts are only good for 40-50k miles so I'm guessing they're due to be changed anyways. My current plan:
- Koni Yellow (Sport) shocks and struts (on sale for $498 from Race Consulting Agency)
- Keep using the original springs
- BMW Strut tower reinforcement plates (part no. 51717036781)
- Rogue Engineering Rear Shock Mounts (http://www.rogueengineering.com/rogue/S_BUSH/RSM.html)
Now for the questions! First, since I'm only at 50k miles but 10 years on original equipment, I'm not sure what else I should replace while I'm doing the above parts. Should I assume I should also replace the following:
- Strut mounts
- Front and rear bump stops
- Upper and lower spring pads
- Dust boots (do these come with the Konis)?
If so, are there specific brands I should look for, or is OEM sufficient? Is there anything I am missing? I plan to do various bushings later and will post back here with questions about those.
My other question is about the Koni shocks. Currently a whole set can be had for $498 shipped from Race Consulting Agency thanks to a tip from FlyRide here. However, I have had my eye on TC Kline's modified Koni shocks (link: http://www.tcklineracing.com/webdocs.../Details30.cfm) that are externally adjustable like Koni's standard front struts but they're 2.7x more expensive than the normal Koni rear shocks. So my questions are:
- Are there other brands that modify Koni Yellows like TC Kline? I remember people talking about Ground Control but they don't seem to carry modified Konis other than full coilover kits.
- If the TC Kline shock fails/breaks, can they be repaired under Koni's warranty?
- Do I have to cut up my trunk liner/carpet to get the TC Kline shocks to fit?
$264 for the TC Kline vs $98 is a large premium to pay for rear shocks, one I would only consider if I don't have to cut up my trunk carpet/liner and knew that if the shocks failed they could be repaired/replaced by Koni.
All that said any info or suggestions would be greatly appreciated!
EDIT:
For those not wanting to wade through the pages of responses, below is the finalized list of parts that I ended up using for a relatively stock suspension refresh:
- Koni Sport (Yellows) struts (8741-1390RSPORT [front right], 8741-1390LSPORT [front left]) and shocks [2x 8040-1271SPORT])
- Rogue Engineering rear shock mounts (RSM) (no part number)
- Strut tower reinforcement plates (2x) (51717036781)
- Front strut mount (2x) (31336752735) (FCP Euro)
- Front spring pads (2x) (Upper: 31331091867, Lower: 31331096664)
- Rear spring pads (2x) (Upper: 33531136385, Lower: 33531094518)
- Bump stops (2x) (Front: 31306757046, Rear: 33506757047)
- Dust boots (2x) (Front: 31331094749, Rear: 33521136283)
- Z4M Front Control Arm Bushing (FCAB) (Left: 31107836862, Right: 31107836863)
- Z4M Rear Trailing Arm Bushing (RTAB) (2x) (33326770817)
- Hex bolt w/ washer for FCABs (4x) (33306760652)
- Locking nuts for strut mounts (6x) (31316769731)
Total cost (purchased June 2015): $1,002.78. Cost broken down by part can be found here
Notes:
- This list assumes you reuse your stock ZHP springs
- If you want a top-adjustable Koni Sport rear shock, you can use the ones meant for the Porsche 911 (part no. 82101159SPORT). This means the shocks won't have to be removed to be adjusted. I'm not 100% if any modifications are necessary to get the shock to fit or not.
- I chose Z4M front control arm bushings (FCABs) because they are solid rubber so they should last longer, and offer slightly increased caster (slight increase in straight-line stability, slight increased turn-in effort). Many members here have them and like them and have had no issues other than the aesthetic "issue" of the front wheels being pushed slightly forward in the wheel well.
- The strut mounts I purchased were by Lemförder because they were far cheaper than BMW Original and Dane vouched for their build quality.
- As far as I know the hex bolts (33306760652) and locking nuts (31316769731) are not strictly necessary. You can (I think) just use Loctite on the hex bolts and just reuse the locking nuts. I chose to get both since they were relatively cheap (~$15 total) and one of those "while you're in there" sort of things.
- According to the guide by Mango on E46Fanatics about suspension refresh items (link:http://forum.e46fanatics.com/showthread.php?t=932561), you should replace the reinforcement plate bolts (8x 31106772199). I opted not to, but definitely something to consider. On the whole the guide was very helpful.
- I opted to not do the rear trailing arm bushings (RTABs) with this refresh until I hear back from Peter (username: slater) with his opinions on the Bimmerworld sealed spherical RTABs he purchased. If not those, then I plan to purchase OEM M3 or Z4M RTABs with limiters, probably from Vorshlag (link: http://www.vorshlag.com/product_info...roducts_id=515). EDIT: I ended up not waiting on slater (Peter) and purchased the Z4M RTABs (part no. 33326770817) with Vorshlag limiters. I have had no issues and like them so far.
- Bimmerworld sealed spherical RTABs: if you jump to post #56 there's a pretty lengthy discussion about them compared to rubber and poly RTABs. Pictures of the spherical RTABs can be found here The spherical RTABs can be purchased here.
- I originally had the rear bump stops as 33531138109 but those are supposedly for lowered suspensions which is not the case for me since I will be reusing my stock ZHP springs.
- I did not include or replace the "upper spring pocket with spacer" (item 7, here: http://www.realoem.com/bmw/enUS/show...diagId=31_0408, part no. 31326769667) because no one mentioned I should nor did it seem necessary.
- Install notes can be found in my project thread here for the rear shocks and here for the front struts
Additional parts for a suspension refresh to consider:
Note: I have not purchased nor installed these parts, but they are the likely parts I would use if I were to replace these parts.
- Front sway bar end links (2x) (31356780847)
- Rear sway bar end links (2x) (33551094619)
- Front sway bar bushing (2x) (33556751269)
- Rear sway bar bushing (2x) (33551138104)
- M3 Rear outer upper and lower ball joints (4x) (33306852895)
- Front control arms (there is some confusion on part numbers: Link)
Additional Links:
- My thread discussing alternative wheel options
- My thread on maintenance spreadsheets and available templates
EDIT 2: 09/21/2015
I now have everything installed and had an alignment done (FCABs and RTABs w/ limiters installed by an indy). I used Shawn's (username: ELCID86) and Daniel's (username: NoVAphotog) previous alignment numbers to get a rough estimate of where they should be. Initial thoughts are the car feels great! The nose wants to dive into corners, the rear feels very planted when you step on the throttle out of the bends, and it feels very stable in a straight line at high speed. I would highly suggest this setup for anyone wanting to keep their car's ride comfortable but still agile. For a little more of a review on the feel of the car post-refresh and some installation advice, click here.
For those worried about the look of added caster from the Z4M FCABs, below is what my car looks like with them. You will notice the wheel sits ever so slightly forward in the wheel well but you can barely notice it. It doesn't bother me and I like things to match up and be symmetrical.