This article is one in a series that have been released in conjunction with Wayne's new book, 101 Performance Projects for Your BMW 3 Series. The book contains 272 pages of full color projects detailing everything from performance mods to timing the camshafts. With more than 650+ full-color glossy photos accompanying extensive step-by-step procedures, this book is required reading in any 3 Series owner's collection. The book was released in August 2006, and is available for ordering now. See The Official Book Website for more details.
In this continuing series of E30 suspension technical articles, I will focus on replacing the rear sway bar bushings. Over time these bushings swell due to heat and pressure, and eventually will start to erode and crack. If you hear any squeaking or clunking from the rear of the car when you go over dips or holes, chances are the bushings have worn and need replacement. The good news is that replacement is relatively easy and can be performed with hand tools in little more than an hour.
The first step is to loosen the rear wheel lug bolts (but do not remove). Next, jack up the rear of the car on both sides and support the car with some quality jack stands. Keep in mind that you must jack the rear up from a good structural point on the car, such as a frame rail or a suspension carrier. Otherwise, you risk putting the jack right through the floor of the car. (I have seen this happen on a Porsche 914, and it's not pretty). For those of you who are not familiar with jacking the car up, I highly recommend you read Wayne's article on jacking up the E36. It does not apply to the E30, however it is a good reference guide.
Once the car is up in the air and secured on the jack stands, remove the rear wheels. Behind the rotor/hub assembly, you will see the complete sway bar assembly attached to the rear trailing arms. The first step in restoring the bushings is to locate the suspension drop links. These are used to attach the sway bar to the trailing arms. If you look on the top the arms, you will see the mounting nut and bolt for the drop link. Remove the nuts on both drop links. Use an open-end wrench to hold the bolt, while you loosen and remove the nut on the end. Don't try to remove the drop links from out of the bracket just yet. We need to remove the upper connection point. There is a cotter pin on the end of the sway bar that holds the drop link on. Cut the old cotter pin off and slide the drop link off the bar.
Now, take some grease and lubricate the end of the sway bar. Now slide the new drop link into place and put the washer on the end. Once in place, install a new cotter pin and bend it over the sway bar to prevent it from coming out of the hole. Now slide the bottom of the drop link into the mounting bracket and re-install the long bolt and nut on the end. Use an open-end wrench to hold the nut while you torque the bolt to 50 ft./lbs.
Now re-mount the wheels and snug up the lug bolts. Jack the car up again and remove the jack stands from under the car. Lastly, lower the car and tighten the lug bolts.
And that's it, you're done!
As always, if anyone has any questions about this or any other tech article, feel free to email me at The Pelican Parts Message Center