BMW E34 clutch and flywheel: most common faults
E34 clutch pedal is soft or has no feel - why?
The most common cause is air in the clutch hydraulics, especially after a clutch job. Bleed the hydraulics so that the fluid reservoir does not run empty. If bleeding does not help, the fault may be a leaking slave cylinder (the hydraulic cylinder on the gearbox that operates the clutch).
Why does the E34 engine stall when I press the clutch pedal to the floor?
The clutch does not release properly, so the drivetrain stays engaged and the engine stalls. Gears go in only by force. The cause can be, for example, a faulty slave cylinder that leaves the pedal without feel. Check the hydraulics first.
What is checked on the flywheel during a clutch replacement?
The surface is machined on a lathe to remove glazing. The flywheel is replaced if it has clear bluing or many cracks, because they indicate overheating. The dual-mass flywheel's play is checked: a worn one rattles, and a fully worn one must be replaced with a new one.
What else should be replaced when the gearbox is out for a clutch job?
It is worth replacing the gearbox seals, the gear lever bushings and the gearbox oils at the same time. The rear crankshaft seal is replaced unless it is completely dry. Also check the guibo (the rubber driveshaft coupling), the driveshaft centre support bearing and the linkage bushings. On the M20 engine the pilot bearing of the clutch shaft must also be inspected.