Suspension Upgrade (Rear)

Rear Suspension Replacement - Springs & Shocks

Lifted from E30 Tech Website   Disclaimer: E30tech.com cannot be held responsible if these instructions are not correct or do not work for any reason. You perform these instructions at your own risk.

 

Parts List

The following parts were used in this replacement:

2 Rear Ireland Engineering Stage 3 Race Springs - Part # e30rspring
2 Rear Bilstein Sport Shocks - Part # B36-2027 

Tools

You will need many various items/tools to complete this installation:

Various socket wrenches & sockets spanners wrenches 
Vice grips 
Cutting Pliers 
Safety Goggles & Mechanics Gloves (highly recommended) 
Torque Wrench(s)
Jack 

  I suggest you start by placing your E30 securely onto jack stands. Be sure to remove your rear wheels, and make sure your engine is off.   In this article, we will be looking mostly at the passenger side.

Removal

1. Unbolt the exhaust hangers and let the exhaust suspend freely. This will allow your CV joints enough room for clearance during spring removal.

(EDIT: I didn't actually drop my exhaust when I did mine and really didn't need to either)

2. Remove the differential's 19mm mounting bolt. Then, slowly lower the differential an inch or two onto a jack.  

3. Disconnect the speed sensor from the differential. You will be lowering the differential more in a few steps and you do not want to have the speed sensor connected while doing that.

4. Disconnect the rear stabilizer bar connecting link from the trailing arm.  

  5. Remove the bolt connecting the shock to the trailing arm. Once you remove this bolt, the trailing arm will drop down a few inches. Be sure to drop the differential down some more, so you do not place added stress on your CV joints. Lowering the differential in unison with the CV joints will relieve those added stresses.

6. Place your foot on the brake disc and put your weight on it, while you remove the rear spring.

7. Move your inner trunk lining enough to give yourself access to the upper shock mounting bolts. Then, remove the upper shock mounting bolts, while holding onto the shock. If you are performing this on a Touring, learn more about replacing Touring rear top mounts.

Components

Once you remove the shock from your E30, you should have something like the upper part of the picture below. Remove the old hardware from the old shock and reinstall them onto the new shock.

  If your rear shock mounts look anything like that in Picture 9, then I suggest you replace them with new ones.  

Refitting

Installation is the opposite of removal   Be sure to torque your items to the following: - Shock absorber to upper mounting bracket - Bilstein recommended torque - Lower shock mount to trailing arm - Bilstein recommended torque - Stabilizer bar connecting link - 30 ft. lb. (42 Nm) - Differential mounting bolt - 58-63 ft. lb. (80-87 Nm)   Once installed, your springs and shocks should look like that in Picture 10. (Driver side shown)

All Done!!!