BMW E30 rear subframe and trailing arm bushings
How do I replace the E30 rear subframe bushings?
The easiest way is to remove the whole subframe: disconnect the brake hoses, cables, driveshaft, shock absorbers and ABS wires. The old bushing is pulled out with a puller, and a stuck centre sleeve can be drilled open. Do not burn the bushing out of the beam; remove it by pulling.
How can I install the new bushings without a press?
Clean the bushing hole and use soapy water or silicone as lubricant. Pull the bushing into place with a threaded rod, a nut and a large washer. The strength class of the threaded rod must be at least 8.8, preferably 10.9.
Is it worth replacing the rear trailing arm bushings at the same time?
The trailing arm bushings can be left in place if they are intact, and the subframe bushings get replaced in any case. The rear trailing arm bushings are the hardest to remove and install. A two-piece polyurethane bushing is easier to install than the original.
Are polyurethane bushings as stiff as the originals in the rear subframe?
No. The original bushing is bonded to both the trailing arm and the centre sleeve and acts as stiff as a bearing. A polyurethane bushing has play in every direction, so it does not give the same torsional stiffness.