— Before assembly clean and check all parts to be sure they are in good operating condition. Lay parts out in order of assembly on a work bench.
Install shims (arrow) on differential housing studs. NOTE—
Unless the pinion bearing is being replaced or repairs have been made to the differential, install the same shims that were removed during disassembly. If the differential bearing is replaced or repairs have been made to the differential, special differential setup procedures must be carried out. Differential rebuild and setup is not covered in this manual.
Insert 1st - 2nd selector rod into lower hole in housing, making sure locking detent is in correct position.
Install 1st - 2nd gear shift rod detent, spring and plug,
♦ Detent plug to transmission case 17 Nm (12ft-lb)
Place 1 st - 2nd gear selector fork on operating sleeve. Insert output shaft into case so that bearing is supported on case.
Mesh input shaft to output shaft and push both shafts into place so that bearing flanges are fully seated.
— Install bearing flange nuts with lock washers and tighten.
• Bearing flange to differential housing ... 25 Nm (18 ft-lb)
— Install and finger tighten 1st - 2nd gear shift fork pinch bolt.
^ Remove pinch bolts from 3rd - 4th gear shift fork and shift guide. Slide shift fork and shift guide back on selector rod.
manual transmission-controls and case 340-23
Position shift fork onto 3rd - 4th operating sleeve and then slide selector rod into case. Install pinch bolts in forks.
— Insert 3nd - 4th shift rod detent, spring and plug.
Install Porsche special tool P 260 a over shift rods and gear shafts.
Install 5th gear on input shaft with stepped collar facing gearbox. Install reverse gear on input shaft with marking facing away from gearbox.
— Place 5th gear back in neutral position and remove input shaft lock (special tool P 37 a).
^ Turn 1st - 2nd gear selector shaft to left until it stops. Turn it back until unmachined flat inner surface of shift guide is almost vertical.
Do not turn shaft back beyond the center point.
Install washer and spacer onto output shaft. Install 5th gear with needle bearing. Install 5th - reverse gear operating sleeve hub and install operating sleeve.
Lock transmission input shaft with Porsche special tool P 37 a or equivalent.
• Engage 5th gear by sliding 5th - reverse gear operating sleeve forward.
With input shaft locking tool (special tool P 37 a) installed and transmission in 5th gear, both shafts should be locked in place.
— Install and torque input and output shaft nuts.
— Set 1 st - 2nd gear shift fork so that operating sleeve is precisely centered between 1st and 2nd gear synchronizers. Tighten clamping bolt, making sure shift guide is still in vertical position, as described above.
Set 3rd - 4th gear shift fork so that operating sleeve is precisely centered between synchronizers. Install and tighten clamping bolt.
^ Position 3rd - 4th gear shift guide with 2 - 3 mm (0.08 - 0.12 in.) clearance to 1st - 2nd shift guide.
— Tighten 3rd - 4th gear shift guide pinch bolt.
— Engage 5th gear and lock input shaft using special locking tool P 37 a. Loosen and remove nut from end of output shaft.
— Remove 5th - reverse gear operating sleeve.
— Remove shift fork support plate (Porsche special tool P 260).
— Install new gasket between differential housing and gear housing. Place shifter selector rod in gear housing.
^ Install gear housing, making sure detents in housing are correctly positioned in case. Install and tighten housing nuts with washers.
• Gear housing to differential housing 25 Nm (18 ft-lb)
— Install 5th - reverse gear shift rod into housing with detent cutouts up. Position rod in neutral position.
^ Install 5th gear with reverse idler shaft:
• Place gear in cutout in idler shaft and place shaft with gear into position. Stepped collar on gear must face housing.
• Notch in shaft end must engage locating pin in housing.
Install reverse gear on input shaft.
• Lock input shaft using Porsche special tool P 37 a.
• Install castle nut and tighten.
Install thrust washer and 5th gear needle bearing race to output shaft. Install 5th gear with needle bearing.
— Install 5th - reverse gear operating sleeve hub onto output shaft.
— Unlock input shaft by removing Porsche special tool P 37 a. ^ Slide reverse idler gear assembly onto shaft.
— Install sealing O-ring to shaft end.
^ Place 5th-reverse gear shift fork on 5th - reverse gear operating sleeve and gear together. Slide operating sleeve and shift fork on hub and selector shaft.
— Install reverse light roll pin into 5th - reverse gear selector rod with pin flush to back side of shaft.
Lock input shaft with Porsche special tool P 37 a.
• Manually engage 5th gear.
• Install new output shaft nut and tighten.
Reverse idler gear
^ Push reverse idler against stop and position 5th - reverse shift fork so play between reverse idler gear and reverse operating gear is approximately 1 mm (0.04 in.).
— Tighten shift fork pinch bolt.
• 5th gear shift fork pinch bolt 25 Nm (18 ft-lb)
After tightening shift fork pinch bolt, check the play between reverse operating gear and reverse idler gear by lightly rocking reverse operating gear back and forth. The gears must not contact each other. Readjust shift fork if necessary.
^ Turn transmission over and install shift cover in place, making sure operating pawl (arrow) engages shift rod guides.
• Shift cover to transmission housing 24 Nm (17 ft-lb)
— Turn transmission over and install new O-ring to reverse gear idler shaft.
^ Install new selector shaft oil seal in end cover. Install reverse light switch operating pin into case hole (arrow).
— Using new transmission end cover gasket, slide end cover over selector shaft and gears.
• Install cover nuts and washers and torque.
— Install new input shaft seal into clutch release guide tube. Install new O-ring to guide tube and reinstall guide tube.
• Guide tube to differential housing 10 Nm (7 ft-lb)
Install reverse light switch with new sealing washer.
• Reverse light switch to transmission 35 Nm (25 ft-lb)
— Reinstall transmission as described in 101 Engine Removal and Installation. Transmission fluid specification are given below.
Transmission Fluid Specification
• Viscosity SAE75W90
• API classification GL5
• Alternate classification MIL-L2105B
Transmission Fluid Capacity
_transmission & clutch-general 300-1
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