BreakMyWindow 1870 Report post Posted May 8, 2012 Hi All, I'm in a bit of a pickle, and need some clarification before I go ahead with my suspension upgrade. I recently picked up a set of rear springs which are supposedly out of an 01 540i with the M sport II suspension. I was also given another set of rear springs from a 540i that could also be M sport II springs. The springs themselves have no part numbers, and the bmwfans site is of no help either, as the pics of the springs are generic, and have a coil count of 8. The springs that I suspect are the M sport II ones have a coil count of 11, and have a rubber type coating on the top half of the springs. They look identical to the ones in the following link, which is an ebay ad for 03 540i oem sport rear springs and struts. Furthermore, the top mount part number in the pictures matches that of the rear top mount for an e39 540i with m sport suspension II. http://www.ebay.co.uk/itm/2003-BMW-E39-OEM...T-/180581648353 The coil count appears to be correct, and the rubber type coating is there. However, I found another pic of some 01 540i oem sport springs, which have a coil count of 9, and don't have the rubber-type coating on the top half of the springs : http://forums.bimmerforums.com/forum/showt...d.php?t=1723030 Can any one please help with identifying the correct rear springs for an e39 540i with m sport suspension II? Anyone with m sport suspension II in their e39 540i be able to confirm if there rear springs have the rubber type coating in place, and 11 coils? I will post up some pics of the springs I have shortly. Thanks in advance!! Martin Quote Share this post Link to post Share on other sites
BreakMyWindow 1870 Report post Posted May 10, 2012 Here is a pic of 1 of each rear spring sets I have. The one on the left i suspect is the m-sport II spring, and the one on the right, I am not sure. The one on the left also has an extra coil which seems odd if it's an m-sport II spring, and thus should make the car sit lower.. I really wish the springs had part numbers. Can anyone with an e39 540i that has the m-sport suspension II option chime in here? Quote Share this post Link to post Share on other sites
BreakMyWindow 1870 Report post Posted May 10, 2012 Thanks for your input. The ones in the pic on the left have an extra coil, but the guage of the wire is about 3mm thicker. So it's a bit contradictory.. extra coil (softer) thicker guage (stiffer)... The more research I do about m-sport suspension II the more i found out that alot of the components are the same as the e39 m5. i.e the rear top mounts, the upper and lower spring pads, and the shocks themselves all share the same part numbers. I'm wondering if the springs are the same too? I've noticed that the springs have paint on them, I've seen white paint, red paint, and even orange paint on the rears from different 540i models. I'm wondering if this paint colour represents the type of suspension used.. The saga continues. Quote Share this post Link to post Share on other sites
kiwi535 538 Report post Posted May 11, 2012 (edited) Thanks for your input. The ones in the pic on the left have an extra coil, but the guage of the wire is about 3mm thicker. So it's a bit contradictory.. extra coil (softer) thicker guage (stiffer)... The more research I do about m-sport suspension II the more i found out that alot of the components are the same as the e39 m5. i.e the rear top mounts, the upper and lower spring pads, and the shocks themselves all share the same part numbers. I'm wondering if the springs are the same too? I've noticed that the springs have paint on them, I've seen white paint, red paint, and even orange paint on the rears from different 540i models. I'm wondering if this paint colour represents the type of suspension used.. The saga continues. take the springs to a local spring place ,they can calculate the properties.Re motorsport suspension i think the M5 is slightly lower again than a motorsport Edited May 11, 2012 by kiwi535 Quote Share this post Link to post Share on other sites
BreakMyWindow 1870 Report post Posted May 18, 2012 Anyone know of a place in Auckland that has equipment to be able to work out what the spring rates are? Quote Share this post Link to post Share on other sites
HELLBM 1531 Report post Posted May 18, 2012 This info might be of some use: How is the E39 M5's suspension different from that of a regular 5 Series? The suspension of the E39 M5 shares its basic aluminum-intensive MacPherson strut/multi-link design with that of the V8-powered E39 5 Series models but incorporates several specific changes from BMW M: -Specific spring rates with reduced spring height (0.9-inches shorter than standard E39 springs, 0.1-inches shorter than M-Technic E39 springs) -Specific shock valving -Thicker anti-roll bars front and rear -Polyurethane auxiliary springs in place of rubber units -Steel balljoints in place of rubber rear suspension bushings Quote Share this post Link to post Share on other sites
BreakMyWindow 1870 Report post Posted May 29, 2012 (edited) I Have taken both different springs in to a suspension specialist. The spring with the top half coated in a rubber like material have a spring rate of approx 160 pounds/inch. The other, approx. 130 pounds/inch. The spring with the lower spring rate sits approx 20mm lower with 500pounds of weight placed on them, compared to the spring with the rubber type coating with 500pounds of weight on it. So my thoughts at first are that the spring with the lower spring rate, that sits 20mm lower should be the sport spring (since I know that sport model e39's sit lower than non sport models) However, the springs with the higher spring rate, which sits higher seems to fit better in to the spring pads that are specified with cars that had the m-sport suspension II option. The spring pads accomodate for the slightly thicker spring coils... hrmmm.. I wonder if the rubber type coating on the rear springs of e39's is only for m-sport suspension II cars, or if this was something that BMW did for later model e39's. I do know that there were various spring rates used for cars based on their options. So a car with lots of the options carries more weight on the springs, thus the spring rate needs to be higher. This I think is represented by a coloured marking on the springs. This adds to the fun. Ray - do you have any late model 540i rear springs that are out of a non sport model, that have the rubber type coating in the yard? Edited May 29, 2012 by BreakMyWindow Quote Share this post Link to post Share on other sites
BreakMyWindow 1870 Report post Posted October 18, 2012 Thought i'd update this thread with some of my research efforts. BMW springs do indeed have part numbers afterall, after cleaning the springs i bought, i noticed some faint numbers on the bottom coil. I put some paint stripper over the area, and cleaned off the paint. The part numbers are engraved in to the steel. Using the WebETK and a chassis number i got off a 2001 540im sport, i looked up the spring table. Knowing that there are several spring part numbers front and rear, based on an individual cars axle weight, the part numbers go up or down in sequential order. The front springs I bought happened to match the part number (the last half of the full bmw part number that Webetk shows is engraved in to the spring) The rears were off by one number. That's close enough for me to confirm the springs I got were indeed of an 01 540i m -sport. New springs and shocks going in next week! :-) Quote Share this post Link to post Share on other sites
qube 3568 Report post Posted October 18, 2012 ^ seems like you went through a lot of effort! nice enthusiasm... Quote Share this post Link to post Share on other sites
