My rear spring broke. Apparently, this is quite a common occurrence on the E46 BMWs. I mean, why wouldn’t a car that was $35,ooo when new have springs that break by 100k miles for no good reason at all? Gotta love BMWs!
Because it’s such a common problem, here’s a DIY guide to fixing it.
Vehicle • BMW E46. 325xi, specifically. As far as I know, this applies to all years and models of the E46.
Difficulty • 3/10 If you’ve ever done any suspension work, or replaced your brake pads or rotors, this will be quite easy for you.
Time • 20 to 30 minutes per side.
- Floor jack and two Jack stands, and a roughly 1 foot piece of a wood 2×4
- Long 1/2 ratchet or breaker bar
- 1/2 ratchet
- Torque wrench (optional, but preferable)
- 17mm socket for wheels bolts
- 18mm socket for the rear shock bolt
- New rear coil springs
- Spare tire jack from your trunk
- Penetrating oil (PB Blaster or similar)
(All photos show the new spring. Please ignore that.)
Step 1 • (No picture, sorry.) Car off and in park, e-brake on. Loosen your wheel bolts.
Step 2 • Jack up the rear of the car by placing your floor jack under the rear differential carrier. I like to use a piece of wood so that the steel doesn’t get damaged by the jack. Your jack has to go under the car with the handle down. Your first pumps on the jack will be quite short. It’s kind of tedious, but this is the correct way to do it.
Step 3 • Put jack stands under the rear jack pads, closer to the front of the car because the pads will go forward as the car is lowered onto the stands.
Step 4 • (No picture again) Remove the wheel bolts and the wheels from both sides. I didn’t realize this originally, but someone pointed out to me that it’s important to do both sides together–as opposed to doing the whole job on one side, then putting the wheel back on and switching to the other–so that sway bar isn’t a problem when pushing down the control arms.
Step 5 • Place your jack–again, using a piece of wood so you don’t damage the steel–under the shock, just enough to relieve pressure but not enough to lift it up. Use an 18mm socket–1/2 drive, preferably–to remove the bolt. If you have any trouble, spray the bolt with penetrating oil and let it sit for a few minutes. Pull out the bolt and lower the jack. Go to the other side and repeat so that both control arms are detached from their shocks.
Step 6 • Remove the wires from the trailing arm so that you don’t damage them, and place the base of your spare tire jack on the trailing arm. You can see the jack placement in the photos. Carefully raise the jack, making sure to not hit the car’s paint. As you do this, the control arm will lower, and the spring should pop out. Repeat on the other side so that both springs are removed.
Step 7 • (No picture) Remove the upper and lower pads from the springs, and transfer them to your new springs.
Step 8 • Carefully guide the new spring into position, making sure the upper and lower pads are oriented correctly. Once you’re confident that the spring is in the right place, and the metal protrusions from the car body and control arm are in the openings in the spring pads, you can decompress the jack and repeat on the other side.
Step 9 • Jack up the mounting point for the rear shock, making sure it’s level with the bolt hole in the shock. Reattach the bolt, and torque it to 100Nm. ( http://www.argyrides.eu/bmw/mods/suspension/pdf/torque_values.pdf ) Repeat on the other side.
Step 10 • Mount your wheels, lift your car up from the differential carrier to remove the jack stands, lower it down, clean up, then go for a short test drive!