Replace seat bottom upholstery - Sport seat

# Replace seat cover - lower - sport seat.

When buying a seat bottom cover for a BMW sport seat, you get a kit that includes 3 pieces. The base and two side bolsters. Each piece is individually replaceable.
Place seat in lowest position. |
Move seats fully rearward, remove caps from nuts and remove the 17mm nut from front of each rail. |
Move seats fully forward and remove the two 17mm bolts from rear of rails. |
Disconnect seatbelt switch wiring from below drivers seat |
Lift seat out of car carefully to avoid damaging paint or trim. |
Release back rest and lay forward. Remove screw from each lower corner of backrest cover |
Pull knobs off release handles by inserting a small screw driver between the knob and the plastic base. Long handle knob on outside of seat shown. Shorter knob on inside edge of passenger seat is removed with the same method. Some force is required. |
Remove handle trim by prying on lower end. Lower end is secured by a push pin, upper end is secured by a hook, you must pull the lower end away from seat, then pull the trim downwards to release. |
Passenger seat: Remove screw from inner lever and remove. |
Pull seat back cover away from base of seat back and up to release from clips at top of seat back. Pull inboard side away from seat back and remove over handle on outboard side of seat by turning seatback cover as you remove it.
Unscrew plastic nut securing trim to each hinge. |
There is a pin securing the trim (blue arrow), approximately 50mm above the pin for the plastic screw (green arrow). |
Insert a long screwdriver behind the trim in this area and pry outwards to release. |
Gently pry tab back on white plastic cable guide and remove guide from each hinge. |
Pry tab back on cable end far enough to clear end of pin and remove cable on each hinge assembly. |
Remove the #3 Phillips screw from the back of each hinge. |
Heated seats: disconnect seat back heater wiring. |
Lift backrest straight up and off hinges. |
Raise seat base to it's highest position. |
Remove 17mm bolts from the rear of the seat rail, one side secures the seat belt latch. There may be a plastic cover over the outside bolt, pry this cover off with a screwdriver. |
Pry off the release lever on the pivot of the mechanism. |
Remove C clip from shaft. |
Use a screwdriver to pry the connecting tube from the hinge assembly. |
Unlock seat back release lever and rotate entire assembly until head of pivot shaft is at large end of opening. |
DANGER : Do not use a finger to unlock mechanism. Spring struts are under pressure and injury may result. Use a screwdriver to move back the lever.
Lift assembly up off pivot shaft and seat rail. Repeat process on other side. |

The forward seat rail pivots are secured by "Saxionia" pins. There are two slightly different types of pin, both work on the same principle. The idea is to pull back the hook(s) (green arrow) on the inside of the pin, then slide the pin out.

Often one or more of the pins will have been replaced with a bolt.

Pulling back the hook is achieved by inserting a narrow screwdriver into the pin, which forces the hook(s) to retract, then pulling the pin out. This procedure usually damages the pins, replacement on assembly is recommended. |
Disconnect linkage rod for seat adjustment by rotating clip off rod and pulling rod from socket. |
Move thigh bolster to a position where clip can be removed. |
Remove clip and pivot pin. |
Slide bolster off front of seat. Note, bolster is attached to seat base by upholstery. |
Pry back the two tabs on each end of bolster and pull upholstery over them. |
Pull channel off front and rear of bolster. |
Remove metal support and foam. |
To gain clearance for pliers to remove bolster adjusting knob, remove clips from thigh bolster adjusting mechanism and pull knob away from seat. |
Remove knob for bolster adjustment. Rod is spiked before installation of knob, to ensure secure fitment. Place a set of locking pliers on the shaft below the knob for leverage and use a pair of trim pliers or a pry bar to lever knob from shaft. |
Remove pin (green arrow) and slide plastic side cover forward to disengage rear pin (blue arrow). Click on image for enlarged view. |
Slide rails off connecting tube and remove. |
Slide steel connecting rod out of upholstery. |
Remove lever for front seat height adjustment (if fitted). |
Cut hog rings securing base to frame. |
Bend back retaining spikes along rear edge of seat and remove seat base from frame. |
Cut hog rings securing bolster covers. |
Bend back retaining spikes for side bolsters and remove covers. |
Gently remove foam padding from frame and check integrity of frame and welds. When bolsters are loose, it's usually due to a break at the arrowed point. |

### Installation:

Seat base material is stapled to foam. Hog rings can be used but are not as durable. Most upholstery shops will be able to staple the new material to the foam. |
Ensure correct fit of side bolster foam. |
Pull bolster material tight and secure with new hog rings. |
Outside bolster will require an additional hole if seat has adjustable front height lever. Install bolster cover totally, then locate adjusting rod, cut hole and install lever. |
Pivot pin must go totally through reclining mechanism. |
Ensure snap ring locks in on hinge mechanism. |
Check that back rest seats correctly on hinges. |
Fit rear edge of plastic side cover first. |
Ensure hinge section is in large cut out of sliding cover and cable is in small cutout. |
Hooks on back rest cover must engage frame. |
Screws for back rest cover must have load spreading washers fitted. |
Lever for inboard side of passenger seat must be inserted into slot in mechanism before installing screw. |

E30 M3 Repair Manual V2.7. Copyright ©1999-2001 Koala Motorsport & Brett Anderson