Flex Disc / Guibo - E34 540i 6MT, E39 540i, E32 740i, E38, E31 840ci, Z8

The flex disc, aka guibo, for the 540i, 740i, 840i, and Z8 connects the driveshaft to the transmission and provides a buffer to absorb driveline vibrations. The rubber flex disc takes the torque coming out of the transmission and delivers a seamless transition to the driveshaft. But over time the rubber is subjected to constant loading/unloading and it will break down. The rubber is designed to be the weakest link so that the rest of the driveline lasts longer.

Fitment note: E34 540i is for 6-speed manual only.

Symptoms of a failed guibo will be a dull thunk when dipping in/out of the throttle and during shifts. You may also notice cracks in the rubber around the bolt holes. A great time to replace the guibo, and driveshaft center support bearing, is during a clutch overhaul, short shift kit install, or any time the driveshaft is removed from the car.

This part is manufactured by an aftermarket supplier of European auto parts, including many rubber components. While not carrying OEM status, this part follows the design of the original very closely and uses similar materials. An aftermarket part may even have the same TUV approval as its OEM counterpart. The brand may even be OEM to another manufacturer besides BMW. This aftermarket brand has a two year warranty - the same as Genuine BMW and OEM brands.

We also recommend replacing the 6 self-locking nuts at the same time.

Install note: the flex disc is directional. During install, look for an arrow on the outer rim. The arrow should point towards the flange and indicates the direction the bolt should go. Installing it backwards will cause premature failure of the flex disc.