Strange handling or noises in the rear may indicate a broken rear sway bar mount. The Factory fixed the mounting plates in late 911s, but all owners of 911 and 930 1978-89 can upgrade to this improved heavy gauge steel mount. Note: Before buying just one new plate, carefully inspect the other side. If one has broken, the other may be failing. To install, you must grind off the old mount and weld on the new one, so we recommend you have a shop do it.