E36 and E46 BMW Rear Trailing Arm Bushing (RTAB) Replacement

BMW's previous two generations of 3 series cars (sedan, coupes, and convertibles) are extremely popular. There are many thousands of them on the road. The oldest E36 BMW's are now 15 years old and often have well over 150,000 miles on them. The oldest E46 3 series' on the road are now 8 years old and are cracking the 100,000 mile mark. As both generations share very similar rear suspension design, both generations have exhibited similar wear item issues for BMW enthusiasts to be aware. One of those issues is the failure or exteme wear of rear trailing arm bushings, which can be worn out in as little as 50k miles! Symptoms of bad trailing arm bushings include side movement of the rear end under acceleration, general looseness of the rear over bumps, and abnormal tire wear. There are two ways for the backyard/DIY bimmer enthusiast to address this: one repair involves purchasing or renting a special tool for the job, this write up allows you to get the rear trailing arm bushing (RTAB) done without using special tools. You will definitely want to see if your car is in need of this repair. Some instances of RTAB failure were so extreme that the threaded holes for the 3 mounting bolts fatigued, allowing the arm to break away from the car body! You will need new, upgraded RTABS, preferably the OEM or aftermarket specification ones for the 1996 - 1999 E36 M3. Several companies also sell shims for further peace of mind, but this is not crucial. You will need 2 18mm sockets for getting the 18mm bolt out of the rear trailing arm bushing, a large straight slot or flathead screw driver, a hammer, power drill, 7/16" drill bit, and other metric sockets to remove items to get at the rear trailing arm. Once your BMW is securely supported on jackstands, remove the rear wheels. Remove the 10mm bolts that hold the brake lines to the rear trailing arms. This prevents unnecessary strain on the brake lines. Remove the bracket but only after making sure you have noted where bracket lines up. I mark both sides and take pics with a digital camera! Remoe the 3 18mm bolts and then then the 18mm bolt securing the RTAB to the bracket. I recommend liberal use of a penetrating oil like PB Blaster or similar, plus a breaker bar or similar tool to get this off. Now we have to figure out how to get the old bushing out of the arm. Use a 5/16" drill bit to drill holes around the aluminum center in the bushing. What you are trying to do here is rip out the center part of the rear trailing arm bushing. Measure the gap between the flange and the trailing arm with feeler gauges and note the gap measurements as you'll need to put the new bushing in with the same gap. To get the rest of this bushing out take your huge flat head screw driver and put it between that flange and the trailing arm and start hammering away on it. The metal of the bushing should start to bend inward toward the hole you drilled. Use a large flat head screwdriver to bend the bushing in and eventually wedge the bushing right out of the RTA. An air chisel was suggested in another write up of this repair. Hint: Dish soap liquid makes a good bushing lubricant. You are going to either have to get the special tool to press your E36 or E46 rear trailing arm bushings in, or make your own crude press. Stay tuned for the next installment of this repair...but first I've got some E34 5 series stuff to work on...