Center support, replace

Remove exhaust system

Remove heat shield from above exhaust. Secured by two 10mm screws at the rear (yellow arrows) and a total of twelve 13mm bolts (green arrows) including the 6 securing the cross brace just behind the transmission.
Remove the three 17mm nuts and bolts securing the "Guibo" coupling to the transmission. Leave the Guibo attached to the driveshaft.
Loosen threaded ring at center support. This is best achieved with two large pairs of pliers, apply one set of pliers to the threaded ring (green arrow) and the second set to the weld in the driveshaft tube (yellow arrow). The weld is a rough surface and gives good grip, preventing the pliers from slipping and scarring the tube. It is also the strongest section of the tube. Loosen ring approximately 5 turns.
CAUTION: Drive shaft is balanced as a unit, do not separate the two halves without marking them for correct re-assembly. The factory marks both halves with a dot of silver or white paint. Ensure these paint spots are present, or add new ones before continuing.
Remove bolts from center support, push front section of driveshaft backwards, collapsing the slide joint at the center. Pull driveshaft down at center and off transmission.
Slide front section of drive shaft out of rear section. Tie rear section up with wire so that it does not rest on fuel transfer pipe.
Remove circlip from splined shaft and remove metal dust cover from bearing.
Press center support off splined shaft.
Remove dust guard from behind center support.

Installation:

If dust guards are damaged, replace with new ones.
Place new center support so that open end is facing universal joint.
Check center bushing on transmission end of shaft, replace if necessary, lubricate bushing with grease.
If Guibo has been removed from driveshaft, ensure that arrows on Guibo point to a flange. White arrows show position of arrows on Guibo. Green arrows show orientation of those arrows. Each arrow is pointing towards either the transmission output flange, or the driveshaft flange.
Damper (if fitted) bolt holes are to match transmission output flange bolt holes.
Pre-load center support by moving forward 4 - 6mm from it's relaxed position, before tightening. Ensure bracket is straight before tightening.
Replace gasket and nuts at exhaust manifold flange. Use copper nuts.
Install manifold nuts and muffler mount and tighten before installing other mounts.
Correctly positioned exhaust must have tailpipes in center of opening in rear valance.
Install transmission bracket on exhaust so that there is no stress on either part.
Install rubber hangers and brackets at rear sub-frame and position bracket so that rubber hanger has slight tension only.

Torques
Center support :	22 Nm (16 ft lbs.)
Guibo :	10mm 8.8 bolts, 46 Nm (33 ft lbs.) ; 10mm 10.9 bolts, 72 Nm (52 ft lbs.) ; 12mm bolts, 123 Nm (89 ft lbs.)
Rear flange to differential :	72 Nm (52 ft lbs.)
Threaded sleeve :	17 Nm (12 ft lbs.)
Pipe to manifold, spring style :	10 Nm (7ft lbs.), after all are at this spec, back off all nuts 1˝ turns.
Pipe to manifold, triangular flange :	22 Nm ( 16 ft lbs.)
Pipe to manifold, all others :	Step 1, 30 Nm (22 ft lbs.) Step 2, 50 Nm (26 ft lbs.)
Bracket to transmission :	22 Nm (16 ft lbs.)
Muffler brackets :	M10, 16 Nm ( 11 ft lbs.). All others, 14 Nm ( 10 ft lbs.)
Hanger bracket to rear sub-frame :	22 Nm (16 ft lbs.)

E30 M3 Repair Manual V2.7. Copyright Š1999-2001 Koala Motorsport & Brett Anderson