How to Rebuild a Jetta 1.8L Transmission

Rebuilding the transmission of your 1.8 Liter Volkswagen Jetta may save you a considerable amount of money. The cost to have someone else work on the transmission of your vehicle can be cost prohibitive, regardless of the make or model. With foreign-made cars the costs can be even higher due to the unavailability of parts and qualified technicians to work on the transmission.

Instructions

Removal

1

Prepare the transmission for removal by mounting the Jetta's transaxle in a mounting fixture and installing a shaft support bridge.

2

Drain the gearbox for the oil and take the clutch push rod out of the Jetta's input shaft.

3

Remove the housing cover bolts with a wrench or a ratchet. Take out the shaft lock nut, the vehicle speed sensor, the selector shaft cover and spring.

4

Place the selector forks in the neutral position and pull out the selector shaft. Remove the reverse idler gear shaft by taking out the Torx bolt.

5

Take out the drive flange cover, washer and circlip and then pull out the drive flange.

6

Engage and reverse the transmission's fifth gear. Take out the retaining bolt for the synchronizing hub and the plate that secures the selector tube. Remove the shift fork by turning the selector tube counter-clockwise. Pry out the fifth gear, shift fork and synchronizer hub all at once. Pry carefully to avoid damage.

7

Take off the tension bracket on the deep groove ball bearing located on the input shaft. Remove the shift fork after first pulling the selector rod. Take off the fourth clip from the output shaft. Make sure that the transmission is not in reverse and then take out the input shaft assembly, along with the second and third gear, synchronizer ring and needle bearings. Knock out the reverse gear shaft by butting a bolt against it and hitting the bolt with a plastic hammer or rubber mallet.

8

Remove the reverse gear, synchronizer hub, first gear and second gear inner needle. Also take off the cover bolts for the bearings, along with the thrust washer and cover. Additionally remove the output shaft, drive flange on the right side, differential assembly, tapered ring and thrust washer.

Assembly

9

Place the differential into the clutch housing and then install both the bearing cover and the output shaft. Tighten the output shaft bearing cover to 30 foot-pounds of torque. Also install the inner thrust washer, synchronizer hub, first and second gear needle bearing inner race on the output shaft. The synchronizer hub should then be heated to about 212 degrees Fahrenheit.

10

Install the bearing race for the second gear needle, along with the needle bearings, second and third gear and the synchronizer ring. Ensure that the second gear is facing the shoulder. Install a new circlip as well.

11

Place the input shaft into the clutch housing and then replace the fourth gear with the shoulder facing the fifth gear. Install a new circlip here also. Put in the deep groove ball bracket and then install the tension bracket and then the selector into the clutch housing. Install the shift forks, including the fork for the reverse gear. Put the selector rod in position and then ensure that the reverse idler gear shaft is properly aligned.

12

Reinstall the housing for the transmission, ensuring that the support bridge provides enough support to do the job properly. Place the Torx bolt into the gear shaft for the idler and tighten it to 15 foot-pounds of torque. Secure the housing with hex head bolts, torquing each one to 18 foot-pounds. Tighten the tension bracket for the deep groove bearing to 11 foot-pounds.

13

Heat the fifth gear to 212 degrees and then install it, along with the thrust washer and the appropriate-sized circlip.

14

Turn the shift tube in a clockwise direction using a tube wrench and then engage both the fifth gear and reverse. Thread the bolts of the synchronizer hub bolt using threadlocker. Tighten it to 111 foot-pounds of torque. Place the shift fork in the neutral position and then insert both the selector shaft and the selector shaft spring before covering them with a new seal seal ring. Tighten this assembly to 47 foot-pounds.

15

Add sealant to the selector shaft lock bolt and then tighten to 30 foot-pounds of torque. Adjust the selector fork for the fifth gear, but be careful that you don't cause the transmission to come out of gear in the process. Check and adjust the shift tubes. Attach the gear selector lever onto the selector shaft by bolting it in place. Engage the fifth gear. Raise the operating sleeve and the shift fork, if necessary, to compensate for any free play between the various components.

16

Make adjustments, as necessary, and ensure that the synchronizer ring can move freely. Use a new securing plate to ensure that shift fork is supported and then release the tension on the support bridge. Install the clutch pushrod by pushing it through the end of fifth gear first. Also install the clutch release bearing, the housing cover gasket and the cover.

17

Ensure that all gears shift properly and then finally install the drive flanges, flange covers, dished washers and circlips to finish the job.