//Audijimâ€™s .658 5th gear installation procedure on a Mk IV Golf TDI (ALH)/ 02J (EGR) 5 speed: Parts needed: 02Z 311 158 A (Large Gear) 02Z 311 361 A (Small Gear) 02A 311 324 C Concave Spring Washer for small gear 02A 301 215 A Gearbox Cover Gasket 2.0 liters (+/-) VW G50 (or alternate brand) full synthetic gear oil 75W/90 Tooling: Metric Tool set 11 mm socket for gearbox Cover bolts 17 mm socket to remove wheel lug bolts 17 mm Allen socket for drain/fill plugs 8 mm Triple Square for the Selector Fork mounting bolts T60 Torx socket for the bolts that hold on 5th gears T25 bit to remove the screw for the inner fender liner Electric heat gun or propane/MAPP gas torch (as needed) Gear Puller, 3 arms Torque wrench in ft/lbs. Oil Catch Impact gun (if you have air tools available) Procedure: -Inventory your parts. -Inventory your tool list. -Review Maintenance Manual Procedure(s). -Position vehicle for maintenance. -Place Wheel Chocks behind rear wheels. -Jack up the front of the vehicle. (Refer to Ownerâ€™s Manual or Maintenance Manual for proper Jack Points) -Place vehicle on jack stands. (Refer to Ownerâ€™s Manual or Maintenance Manual for proper placement) -Remove Front Left (driver side) wheel with 17 mm socket. -Remove Inner Fender Liner with T25 Torx bit. -Clean the area around the Fill and Drain plugs to prevent internal contamination. -Loosen and Remove Fill Plug. Clean Fill Plug. -Loosen Drain Plug. -Position Oil Catch under the Drain Plug. -Continue with the removal of the Drain Plug. Clean Drain Plug. -Remove the 5 Bolts that hold on the Gearbox Cover with the 11 mm socket. Loosen the top bolts first in the event that all the gear oil has not drained out of the Drain Plug hole. There will be residual gear oil behind the gearbox cover. -Remove the Gear Selector Bolts with the 8 mm Triple Square socket. -Remove the Gear Selector Pins and Gear Selector Lever. -Remove both Torx bolts with the T60 Torx socket. You may need to have a second person help you by applying the brakes to hold the transmission from turning. These were easily removed with an impact gun. -Note how the OLD GEARS are oriented on the shafts. The NEW GEARS will be installed the same way. Pay attention to how flush the gears are to the ends of the shaft. -The Synchronizing Hub has Spring Circlips on the Outside (facing you) and Backside of the gear. The Circlips hold the 3 Locks in place. -Remove the Spring Circlip and slide the Locking Collar BACK. -Reinstall the T60 Torx bolt finger tight. -Install the Gear Puller arms into the 3 slots that do not have the Locks. The gear puller arms need to fit behind the synchronizing hub. -Apply heat to the Synchronizing hub and/or Aerokroil/PB Blaster, ect to the splined shaft area. -Remove Remove Synchronizing Hub with Locking Collar. -Note the position of the 3 Locks that are being held in with the Spring Circlip on the back side of the synchronizing hub. -Remove the Synchronizing Ring. This may have come off with the Synchronizing Hub and Locking Collar or it may still be on the Large 5th Gear. -Remove Large 5th gear. It rests on Needle Bearing set in a plastic cage. -Remove the Small 5th gear. It is on a splined shaft. A little wiggling of the gear will allow it to slide off. - Clean the Synchronizing Hub and Locking Collar, Needle Bearings, Spring Circlips, Locks, Synchronizing Ring, Selector Lever and Pins, and the Gearbox Cover. -Clean the transmission case. -Heat the new Small 5th gear with Electric Heat Gun or Propane/MAPP gas torch. -Install new Small 5th gear (02Z 311 361 A) on Splined Shaft. -Lubricate the Needle Bearings with VW G50 (or alternate brand) full synthetic gear oil 75W/90 -Install Needle Bearings on shaft. -Install new Large 5th gear (02Z 311 158 A) -Install Synchronizer Ring on the Large 5th gear. -Assemble the Synchronizer Hub/Locking Collar/Locks and Spring Circlips. Note the 3 grooved teeth on the Locking Collar. The Locks fit at these positions between the Narrow Grooves on the Synchronizer Hub and the Locking Collar. Note the orientation of the Locks were they were removed and Install the same way. Install the Spring Circlips. -Heat the hub of the Synchronizer Assembly with an Electric Heat Gun or Propane/MAPP gas torch. -Install Synchronizer Assembly on the Splined Shaft. Be careful not to damage the Synchronizer Ring that sits on the Large 5th gear, it may have slipped off the Large 5th gear. Make sure it is resting flush against the Large 5th gear. -Install the Small Concave Spring Washer (02A 311 324 C) with the T60 Torx bolt on the Small 5th gear. -Note the orientation of the Concave Spring Washers. The cone should be against the bolt, the outer edge of the Concave Spring Washer should be against the Small 5th gear. -Install the Concave Spring Washer that was removed earlier with the T60 Torx bolt onto the Large 5th gear shaft. -Note the orientation of the Concave Spring Washers. The cone should be against the bolt, the outer edge of the Concave Spring Washer should be against the Synchronizer hub. -Torque T60 Torx bolts to 59 ft/lbs (80 Nm). You may need the assistance of a second person to apply brake pressure while you torque these bolts. -Install the Selector Lever and Pins with the 8mm Triple Square bolts. -Torque the 8 mm Triple Square bolts to 18 ft/lbs (25 Nm) - Install the Gearbox Cover with new gearbox Cover Gasket (02A 301 215 A) with 5 11mm bolts. -Torque the Gearbox Cover bolts to 9 ft/lbs. -Install Drain Plug with 17mm Allen socket. -Torque 17mm Drain Plug to 20-25 ft/lbs. -Service Transmission with 2.0 liters (+/-) or until full of VW G50 (or alternate brand) full synthetic gear oil 75W/90. Make sure vehicle is Level when Servicing Transmission. Fill gear oil to the Lower Edge of the Filler Plug Hole. -Install Fill Plug with 17mm Allen Socket. -Torque 17mm Fill Plug to 20-25 ft/lbs. -Install Inner Fender Liner with T25 Torx screws. -Install Front Left (Driver Side) wheel. -Torque Wheel Lug Bolts to 95 ft/lbs. -Start vehicle and check for leaks. -Test drive vehicle, check for leaks again. -Enjoy the added fuel mileage by dropping your RPMs at highway speeds!