VW Passat & Audi A4 1990-2000

Halfshafts

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The front halfshafts are used to couple the transaxle to the road wheels. This allows power to be delivered as the suspension moves up and down and while the wheels are turned side to side to negotiate turns. In order to accomplish the ability to simultaneously supply rotational power and the ability to change direction, an axle must have a component that can pivot and rotate at the same time.

This is accomplished by using a halfshaft with an inner and outer Constant Velocity (C/V) joint. In order to lubricate the CV joint, the joint is assembled using approved high-temperature molybdenum disulfide grease capable of withstanding extreme pressure and heat. The grease is retained in the CV joint by a tapered accordion boot, which is installed over the axle and the CV joint.

The CV boot allows the CV joint to rotate and pivot, while retaining the lubricant and protecting the CV joint from water and debris.

A torn, damaged or leaking CV boot should be replaced immediately. Loss of lubricant will cause the joint to overheat and damage it. Because these are precision-machined components, they can be quite expensive to replace. The cost of the boot is about 10-20% of the cost of a CV joint.

Typically a failed CV joint makes a clicking noise during acceleration, especially when accelerating from a stop and turning.

removal & installation
1990-97 Passat Models

NOTE
When loosening or tightening axle nuts, make sure the vehicle is on the ground. The axle nut torque is high enough that attempting to loosen or tighten it may cause the vehicle to fall off the jackstands or lift assembly.

  1. With the vehicle on the ground, use a 12-point socket to loosen, but do not remove, the front axle nut.
  2.  
  3. Now, loosen, but do not remove, the front lug bolts.
  4.  
  5. Raise and safely support vehicle.
  6.  
  7. Loosen all and remove all but one of the CV joint to stub axle inverted hex head bolts retaining the halfshaft to the transaxle flange. If necessary have an assistant hold the tire, or remove the tire, install two of the lug bolts and have an assistant hold a suitable and sturdy 3 foot (1 meter) prytool between the lug bolts to prevent the axle from spinning.
  8.  
  9. If not previously removed, remove the front wheels.
  10.  
  11. Disconnect the sway bar link.
  12.  
  13. Matchmark the ball joint to the control arm.
  14.  
  15. Separate the strut from the control arm by removing the bolts securing the ball joint to the control arm. Make sure to matchmark the ball joint to the control arm before loosening the mounting bolts.
  16.  
  17. Remove the remaining CV joint to stub axle bolt and remove the halfshaft from the transaxle drive flange and support it out of the way. Do NOT let it hang unsupported.
  18.  
  19. Remove the outer axle nut and press the halfshaft out of the hub. A suitable press tool may be necessary as a locking agent is applied to the outer CV joint-to-hub splines.
  20.  



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Fig. The lower ball joint-to-control arm mounting bolts are removed to allow enough movement in the strut to withdraw the halfshaft



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Fig. A press tool may me necessary to push the splined end of the outer CV joint out of the hub. The outer CV joint splines have a locking agent installed on them



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Fig. With two bolts installed a suitable prytool can be used to prevent the axle from spinning



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Fig. Support the inner portion of the halfshaft with suitable mechanic's wire



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Fig. Press the axle out of the hub using a press tool



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Fig. Once loosened, a suitable drift can be used to drive the axle out of hub



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Fig. Thoroughly clean the spines of the outer CV joint

To install:

  1. Thoroughly clean the splines of the outer CV joint.
  2.  
  3. Fit the halfshaft to the drive flange and install, but do not fully tighten, the bolts at this time.
  4.  
  5. Apply a 1 / 8 inch (3mm) bead of thread locking compound around the splines of the outer CV joint.
  6.  
  7. Slide the splines through the hub and loosely install a new axle nut.
  8.  
  9. Assemble the front suspension, being careful to align the matchmarks.
  10.  
  11. Tighten the ball joint bolts to:
  12.  
  13. Ball joint-to-control arm bolts: 26 ft. lbs. (35 Nm)
  14.  
  15. Install the wheel and hold it to keep the axle from turning. If necessary have an assistant hold the tire, or with the wheel removed, install two of the lug bolts and have an assistant hold a suitable and sturdy 3 foot (1 meter) prytool between the lug bolts to prevent the axle from spinning.
  16.  
  17. Torque the inner CV joint-to-stub axle bolts to:
  18.  
  19. CV joint-to-stub axle bolts: 33 ft. lbs. (45 Nm)
  20.  
  21. If not previously installed, install the wheel without the wheel trim. Do NOT fully tighten the lug bolts until wheels are fully on the ground.
  22.  
  23. With the vehicle on the ground, torque the wheel lug bolts in a crisscross pattern, then torque the axle nut as follows:
  24.  

Lug bolts:



M12: 81 ft. lbs. (110 Nm)
 
M14: 89 ft. lbs. (120 Nm)
 

Axle nut (Always Replace):



1990-93 Passat 2.0L 9A 16V: 170 ft. lbs. (230 Nm)
 

Passat 2.0L ABA/2.8L AAA:



Step 1: 66 ft. lbs. (90 Nm)
 
Step 2: 45° ( 1 / 8 th turn)
 

  1. Check and adjust the front wheel alignment as necessary.
  2.  

A4 & 1998-Passat Models

NOTE
When loosening or tightening axle nut or bolt, be sure the vehicle is on the ground. Axle nut torque is high enough that attempting to loosen it may cause the vehicle to fall off the support.

  1. Remove the hubcap or center cap.
  2.  
  3. Loosen but do not remove the hex collar bolt.
  4.  
  5. Loosen but do not remove the wheel lug bolts.
  6.  
  7. Raise and safely support the vehicle.
  8.  
  9. Loosen all, and remove all but one of the CV joint to stub axle bolts retaining the halfshaft to the transaxle flange. If necessary have an assistant hold the tire, or remove the tire, install two of the lug bolts and have an assistant hold a suitable and sturdy 3 foot (1 meter) prytool between the lug bolts to prevent the axle from spinning.
  10.  
  11. If not previously removed, remove the front wheels.
  12.  
  13. Remove the remaining CV joint to stub axle bolt and remove the halfshaft from the transaxle drive flange and support it out of the way. Do NOT let it hang unsupported.
  14.  
  15. Remove the outer axle hex collar bolt and press the halfshaft out of the hub. A suitable press tool may be necessary, otherwise drive the axle out using a suitable drift.
  16.  
  17. Remove the ABS wheel speed sensor cable from the brake caliper bracket.
  18.  
  19. Slide the ABS speed sensor partly out of its mount.
  20.  
  21. Remove upper control arm pinch bolt and nut, then remove both arms up and out of the steering knuckle.
  22.  


WARNING
The slots in the steering knuckle must not be widened. Do NOT loosen any other steering knuckle fasteners, otherwise the axle geometry must be checked.

  1. Tilt the steering knuckle out and to the rear of the vehicle, then remove the halfshaft. If necessary, use a press tool to remove the axle from the hub.
  2.  



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Fig. A threaded plastic guide dowel is included in the vehicle's tool kit. Thread it into place to guide the wheel on



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Fig. Apply a light coating of an anti-seizing compound to the lug bolts



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Fig. The screwdriver handle supplied in the vehicle's tool kit is used to start the lug bolts



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Fig. Always loosen or tighten the axle nut or bolt with the vehicle on the ground



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Fig. A close up view of the wheel lug bolts and the axle bolt-1.8L Passat model shown



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Fig. Loosen nut (1), remove the hex bolt, and pull both arms (2) upward and out-A4 model illustrated



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Fig. Always torque the lug bolts using a suitable torque wrench in a crisscrossed pattern

To install:

  1. Install the halfshaft into the wheel hub.
  2.  
  3. Install the upper control arms into the steering knuckle and tighten to:
  4.  
  5. Upper steering knuckle pinch bolt: 30 ft. lbs. (40 Nm).
  6.  
  7. Install the wheel and hold it to keep the axle from turning. If necessary have an assistant hold the tire, or with the wheel removed, install two of the lug bolts and have an assistant hold a suitable and sturdy 3 foot (1 meter) prytool between the lug bolts to prevent the axle from spinning.
  8.  
  9. Attach the inner halfshaft-to-transaxle flange and tighten to:
  10.  

Inner CV joint-to-transaxle flange:



M8 fasteners: 30 ft. lbs. (40 Nm)
 
M10 fasteners: 59 ft. lbs. (80 Nm)
 

  1. install the ABS wheel speed sensor, and the sensor cable into the caliper bracket.
  2.  
  3. If not previously installed, install the wheel without the wheel trim and do not fully tighten the lug bolts.
  4.  
  5. With the wheels installed and the vehicle on the ground, tighten the lug bolts in a crisscross pattern and then the axle bolt as follows:
  6.  
  7. Wheel lug bolts: 89 ft. lbs. (120 Nm)
  8.  

Axle bolt (Always replace)

M14 bolt:



Step 1: 85 ft. lbs. (115 Nm)
 
Step 2: 90° ( 1 / 4 turn)
 

M16 bolt:



Step 1: 140 ft. lbs. (190 Nm)
 
Step 2: 90° ( 1 / 4 turn)
 

 
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