View Full Version : changing OE rear shocks to bilstein
08-02-2008, 12:11 AM
Hey guys, I need some help here.... I wanna change my rear OEM shocks to bilstein and I need to know if the spring have to be change also.
08-02-2008, 09:45 AM
No you need not change springs as long as the Bils are matched. That means stock Bils if your suspension is stock or sport if sport. My Bils are for M3 only and bet yours are too.
Replacing the rear shocks is very easy compared to the front struts.
You didn's spec where you have a coupe, sedan or vert but in general all you need to do is to remove the two nuts on top of the shock on the inside of the trunk (all sensible things apply here like jack stands, etc). The car should be jacked up and supported but you need not even remove the wheels, it makes it easier to do so. The location of the top shock is dependent on which M3 you have as the coupes and sedans are close in location while the convertible is under a rubber cover and you have to have the top rear cover open.
Once that is done just remove the bolt holding the lower shock on. From memory I think it is an 18m/m while the top nuts again from memory are 13m/m.
Once you get the old shock out DO NOT reuse your rear shock mounts unless they show no damage. It is smarter to replace them with upgraded E46 RSMs that are more robust.
Put the new RSM on the new Bils and reinstall the shock. It helps to have someone on top to get one of the nuts on the shock by the way.
Both nuts tightened down then reinstall the 18m/m bolt. Be aware that you will have to push the shock some as it is a pressurized shock and that is normal when trying to align the bottom shock hols, bolt and treaded area...
08-03-2008, 10:21 PM
OMG u have been very helpful... I didn't even think about the shock mount to be changed...btw I have a m3 coupe (forgot to mention)
I got all my tools and i just wanted to make sure about changing the spring
thanks a million, I going to write that down
08-08-2008, 03:07 PM
Don't do it... The only Bilstein for the M3 is a the sport. It was designed to work (but not well), but that's just my opinion) with stiffer lower springs. (In my opinion, they have too much compression damping and feel really harsh unless you run seriously stiff springs. You really should mix and match shocks either. If you are changing shock, buy a complete set. If the car already has Billys in front, go ahead, but I would get Koni's...
08-11-2008, 04:03 PM
Changing the rear shocks is a very simple and staightforward DIY so long as you have all the neccessary tools.
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