11.02.2006: Saab NG900 Manual Transmission Installation

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11.02.2006: Saab NG900 Manual Transmission Installation

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Manual transmission installation on a 1996 Saab 900 (applies to all 1994-1998 900 and 1999-2002 9-3). The goal was to install a new clutch and replace the transmission with a newer, stronger unit. This article covers gearbox installation only, for removal refer to this section.

Tools:

24 mm socket: transmission fill plug (9-3);
22 mm crowfoot wrench: O2 sensors;
19 mm socket: flywheel bolts;
18 mm socket: transmission, subframe bolts;
18 mm wrench: ball joint nuts;
17 mm socket: wheel bolts;
16 mm socket: subframe bolts, engine mounts;
15 mm socket: transmission mount bolts, control arms (optional);
13 mm socket: exhaust, downpipe, shift linkage, battery;
13 mm wrench: delivery pipe bolt;
12 mm socket: pressure plate bolts;
11 mm socket: flywheel cover bolts, subframe brace nuts;
10 mm socket: battery base bolts;
9 mm wrench: battery terminals (13 mm on 9-3);
8 mm Allen socket: transmission drain plug;
8 mm hex screwdriver: lower shield screws;
7 mm hex screwdriver: delivery pipe hose clamps (or a flat screwdriver);
3 mm L-shaped Allen key: transmission lock;
engine support beam or engine crane;
car jacks and axle stands;
pressure bleeder and fresh brake fluid;
hand pump and a 40..50 cm long piece of clear tubing (if slave bleeding is needed);
fresh gearbox oil;
breaker bar.

11.02.2006: Transmission

The replacement transmission came from a 1999 9-3. It's an FM55 505 model, while the original gearbox on the car was FM55 501.

11.02.2006: Left side

The new gearbox came from a scrap yard, so it's a good idea to replace both differential seals.

11.02.2006: Seals

Pry the new seal out using a big screwdriver or a chisel. It's not necessary to remove the entire cover, but I find it easier than doing it right on the gearbox.

11.02.2006: Cover in

Carefully push the new seal in, use a rubber mallet if needed. Install the cover back on and tighten the bolts to 16 ft-lbs with a Torx T40 socket.

11.02.2006: Right side

Do the same on the right side of the differential.

11.02.2006: Seals

The bag shows a GM part number (useful if your dealer uses those, like they do in Canada). The Saab part is #8749046.

11.02.2006: Rear mount

Attach the rear engine mount (30 ft-lbs, 16 mm socket). For a later transmission model, the mount bracket might be different -- check the compatibility if you're upgrading to a newer gearbox.

11.02.2006: Pipe

Time to bleed the slave cylinder. Push the throwout bearing in slowly to compress the piston inside it. When you let go, the bearing will spring back out, but the piston will remain compressed.

11.02.2006: Brake fluid

Attach a 40..50 cm piece of clear tubing to nipple on top of the slave cylinder. Fill the tube with brake fluid to ¾ of its height.

11.02.2006: Pressure

Pump some air into the tube. The slave cylinder will expand, and you will see the fluid level dropping. When the cylinder maxes out, the fluid will stop and the pressure will go up. Release the pressure and compress the slave again. You might see small air bubbles coming out.

11.02.2006: Bleeding finished

Repeat the process several times, add more brake fluid if necessary. When you don't see the bubbles anymore, detach the hose (careful not to spill the fluid all over) and plug the nipple.

11.02.2006: Ready

Lock the transmission in third gear. Make sure you can undo the fill and drain plugs (but keep them in). Lubricate the shaft splines. The gearbox is ready for installation.

11.02.2006: New clutch

I am installing a Viggen pressure plate with a SPEC stage2 kevlar clutch plate. The clutch conveniently comes with an alignment tool.

11.02.2006: Flywheel

Inspect the flywheel. If it's visibly scratched or scored, or has cracks on the surface, you need to take it to a machine shop for resurfacing. Torque the bolts to 59 ft-lbs.

11.02.2006: Alignment tool

Install the clutch with the pressure plate and put the bolts in hand-tight. Insert the alignment tool and make sure the clutch plate it perfectly centered. Tighten the bolts alternately to 16 ft-lbs (12 mm socket).

11.02.2006: Jacks

A specialized transmission jack or a shop crane is preferred, but a pair of regular hydraulic jacks will do the job. Make sure the transmission is balanced, roll it under the car and raise to the engine level.

11.02.2006: Left side

Push the transmission in. Remember that you have to match the splines on the clutch plate and the intermediate shaft in the same time. If necessary, turn the flywheel and/or the driveshaft on the right side. The picture shows the brake line disconnected, it was a part of another job.

11.02.2006: Fitted

The transmission should be perfectly level with the engine in order to go in. Again, a lower control arm bolt works well as a guiding pin. Once you close the gap and the intermediate shaft snaps in on the other side, replace the front bolt with a proper one and tighten it.

11.02.2006: Upper bolts

The three upper bolts are easily accessible from the wheel well, just use a longer extention. Don't forget the fifth bolt in the rear. The torque for these is 50 ft-lbs (18 mm socket).

11.02.2006: Clutch line

Remove the cap from the slave cylinder nipple and attach the clutch line. If you have a cable clutch, attach the cable.

11.02.2006: Clutch line

Insert a locking clip to secure the clutch line. The nipple in front will be used to bleed the clutch once the job is done.

11.02.2006: Bracket

Attach the bracket for the transmission mount, as well as the mount itself (30 ft-lbs, 16 mm socket).

11.02.2006: Support beam

Raise the engine until the transmission mount fits its position on the side member.

11.02.2006: Mount

Tighten the transmission mount bolts to 46 ft-lbs (15 mm socket). Attach the ground wires to the mount bracket, and to the side of the gearbox (17 mm and 13 mm sockets).

11.02.2006: Driveshaft

Insert the driveshaft until the snap ring clicks. Plug in the reverse gear sensor wire.

11.02.2006: Flywheel cover

Install the flywheel cover (two 11 mm bolts).

11.02.2006: Linkage

Attach the linkage to the gearshift rod on the transmission (13 mm bolt), connect the arm to the ball pin and insert the shifter rod into its housing. After the entire installation is finished, the shifter needs to be aligned.

11.02.2006: Subframe

Position the subframe for installation.

11.02.2006: Front bolts

First, raise the front end and screw the bolts in hand-tight.

11.02.2006: Washers

Place the washers on the stanchion arm attachment points.

11.02.2006: Rear end

Jack up the rear end, insert the remaining bolts and align the subframe so it matches the position it was in before the removal. Connect the ball joints and tighten to 55 ft-lbs (18 mm wrench).

11.02.2006: Subframe bolts

Tighten the four corner bolts using a 16 mm socket: front to 85 ft-lbs and rear to 78 ft-lbs + 90°. Tighten the middle bolts to 141 ft-lbs (18 mm socket). If you had to remove the control arms, they need a 15 mm socket at 85 ft-lbs.

11.02.2006: Rear mount

Tighten the nuts on the rear engine mount to 37 ft-lbs (16/17 mm socket).

11.02.2006: Beam removed

Remove the engine support beam.

11.02.2006: Downpipe

Attach the downpipe to the turbo (three 13 mm nuts at 18.5 ft-lbs). Install the front O2 sensor (22 mm crowfoot wrench, 41 ft-lbs).

11.02.2006: Exhaust

Install the rear O2 sensor (22 mm crowfoot wrench, 41 ft-lbs). Seal the joint to the flexpipe and tighten the clamp to 15 ft-lbs (13 mm socket). Install the subframe brace if equipped.

11.02.2006: Delivery pipe

Install the delivery pipe and tighten the hose clamps. Attach the hoses to the bypass valve. Bleed the clutch, shift the transmission to fourth gear and align the shifter linkage.

11.02.2006: Gearbox oil

Fill the gearbox with oil (flush twice if switching to synthetic). Install the battery. Attach the lower shields. Fit the wheels (81 ft-lbs) and lower the car to the ground.

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