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Replacing Audi Front Upper Control Arms
 
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Pelican Technical Article:

Replacing Audi Front Upper Control Arms

Peter Bodensteiner

Time:

1.5-2 hours

Tab:

$100 to $150

Talent:

****

Tools:

13mm, 16mm, 17mm, 18mm, 19mm sockets, 16mm, 17mm, and 19mm wrenches, ratchet, extensions, torque wrench, rubber mallet

Applicable Models:

 
Audi A4 (1997-01)
Audi A4 Quattro (1997-01)
Audi TT (2000-04)
Audi TT Quattro (2000-04)
VW Beetle (1999-02)
VW Golf (2000-02)
VW Jetta (2000-02)
VW Passat (1996-00)

Parts Required:

New control arms, all new nuts and bolts to replace old hardware, anti-seize lubricant

Hot Tip:

Rips or tears in the ball joints on the outboard ends of the upper control arms are a sure sign that you need to do this project

Performance Gain:

Properly functioning control arms will help your car handle properly and will eliminate common front-suspension noises

Complementary Modification:

Front shock/spring replacement, front tie-rod replacement

The front suspension of the B5-chassis A4 is a bit unusual, and that's probably a charitable way of putting it. Primary among its goofy characteristics is an arrangement of two separate upper control arms to form the upper "A-arm" or wishbone. Each of these arms has a ball joint at its outer end. These two ball joints fit into holes at the top of the upright and are held in place by a "pinch bolt."

The pinch bolt is a source of frustration to almost everyone who works on these cars. They are prone to corroding in place, which can cause the bolt to break during its attempted removal. I thank my lucky stars that when working on my Minnesota car, a prime candidate for a difficult pinch bolt, it came off without a hitch. It's a great idea to hit your pinch bolt with a liberal application of penetrating lubricant well before you try to remove it. Spray both the nut and bolt ends, as well as the small gap between the ball joints.

You'll note in the photographs that I have already removed the spring and shock assembly. You can remove the upper mounting plate, control arms, and spring and shock assembly all at once if you wish. The only real difference is whether you remove the two nuts holding the top of the spring/shock assembly to the upper mounting plate while it is in the car or after it is out of the car. If you remove the whole assembly, you can avoid having to remove the two rubber plugs in the engine compartment above those nuts.

Some of the steps and photos in this project are the same as those in the Front Springs and Shocks project. Reference that project for additional information about the front suspension, particularly if you plan to change the springs or shocks along with the upper control arms.

This is the dreaded pinch bolt mentioned earlier.
Figure 1

This is the dreaded pinch bolt mentioned earlier. I'm pointing to the nut on the forward side of the bolt. This long nut and bolt help hold the ball joints at the ends of the two upper control arms in place by pinching that portion of the suspension upright. Many people have reported that this bolt is difficult or impossible to remove, particularly when corrosion is present. A soaking in penetrating lubricant should help. It's a good idea to have a spare pinch bolt prior to removal just in case it is damaged when removing.

A pair of 16mm sockets made quick work of this pinch bolt.
Figure 2

A pair of 16mm sockets made quick work of this pinch bolt.

A stout screwdriver can be used to coax the bolt out of the upright, toward the rear of the car.
Figure 3

A stout screwdriver can be used to coax the bolt out of the upright, toward the rear of the car.

A sharp whack to the underside of the control arm popped the ball joint out of the suspension upright.
Figure 4

A sharp whack to the underside of the control arm popped the ball joint out of the suspension upright. The same technique dislodged the rear arm as well.

Here the ball joints have been removed from the upright.
Figure 5

Here the ball joints have been removed from the upright. Both joints were shot and needed to be replaced, which requires the replacement of the whole arm.

The upper mounting plate is secured to the chassis with three 16mm bolts, which are visible in a triangular configuration within the engine compartment at the top of the shock tower and indicated by red arrows.
Figure 6

The upper mounting plate is secured to the chassis with three 16mm bolts, which are visible in a triangular configuration within the engine compartment at the top of the shock tower and indicated by red arrows.

Use a wrench and/or socket to remove the three bolts and the accompanying washers.
Figure 7

Use a wrench and/or socket to remove the three bolts and the accompanying washers. The forward-most bolt is obscured slightly by the wiring emerging from the ECU enclosure as seen here.

The only remaining fastener holding the shock/spring/upper mount assembly in place is the long 19mm bolt and nut securing the bottom of the shock to the front lower control arm.
Figure 8

The only remaining fastener holding the shock/spring/upper mount assembly in place is the long 19mm bolt and nut securing the bottom of the shock to the front lower control arm. The shock mounts to the forward lower control arm with a nut and bolt that must be removed to extract the strut assembly. Use two 19mm wrenches or sockets.

When the nut is off you can slide the bolt out to the rear, but the rear lower control arm is in the way and prevents its removal.
Figure 9

When the nut is off you can slide the bolt out to the rear, but the rear lower control arm is in the way and prevents its removal. I tried rotating the front lower control arm a bit counterclockwise along its axis, using the still-mounted strut assembly as a lever. This gave enough clearance to remove the bolt. During reassembly, you might try reversing the position of the bolt and nut to avoid this problem next time. You may need to disconnect the front sway bar from the link to do this.

Slip the bottom of the shock off of the control arm and remove the assembly from the wheel well.
Figure 10

Slip the bottom of the shock off of the control arm and remove the assembly from the wheel well.

As mentioned, I had already removed the two top nuts securing the spring/shock assembly to the upper mount before removing it from the car.
Figure 11

As mentioned, I had already removed the two top nuts securing the spring/shock assembly to the upper mount before removing it from the car. This is what you're left with once the upper mount is freed. I've already removed one of the control arm bolts, as seen to the left.

The rubber boot on this ball joint is torn, and the joint itself is damaged and ready for replacement.
Figure 12

The rubber boot on this ball joint is torn, and the joint itself is damaged and ready for replacement.

If you have separated the upper mount from the spring/shock assembly, here's a way to remove the bolts securing the control arms to the upper mount.
Figure 13

If you have separated the upper mount from the spring/shock assembly, here's a way to remove the bolts securing the control arms to the upper mount. Turn the assembly upside down and secure the mount with your foot. This allows you apply the torque necessary to loosen the 16mm bolt and nut.

For the reassembly I have placed the shock/spring assembly in a bench vise.
Figure 14

For the reassembly I have placed the shock/spring assembly in a bench vise. Note the four holes provided for the two studs on the top of the spring assembly. Use the 8 and 2 o'clock positions for the left-side front suspension, as shown here. The right-side front suspension would use the holes at the 10 and 4 o'clock positions.

Attach the upper mount to the top of the assembly with two 13mm nuts
Figure 15

Attach the upper mount to the top of the assembly with two 13mm nuts - you should use new hardware here. Tighten to 15 ft-lbs.

Attach each control arm in its appropriate position with new hardware.
Figure 16

Attach each control arm in its appropriate position with new hardware. Consult the earlier photos for the correct configuration of the unique control arms. The longer arm is toward the front of the vehicle. The nut and bolt are 16mm. Tighten them just enough to hold the control arms in place in a horizontal position.

The Bentley manual specifies that you measure a drop of 47mm, +/- 2mm, from the tip of the upper mount down to the top surface of the control arms.
Figure 17

The Bentley manual specifies that you measure a drop of 47mm, +/- 2mm, from the tip of the upper mount down to the top surface of the control arms. This is where the arms should be positioned as they are tightened into place. The torque spec is 37 ft-lbs, plus a 1/4 turn-a spec that should be finalized after the car is back on the ground. You may find that it's impossible to get a torque wrench onto these bolts at that stage, so get it close for now and then add that 1/4 turn on the ground using a conventional wrench. Alternatively, you could jack up the suspension to where it would be with the car on the ground and then tighten it--this method would give you better access.

The assembly is ready to go back in the car.
Figure 18

The assembly is ready to go back in the car. Note the new shock absorber from the .

As you put the assembly in place, this body-mounted stud threads through a hole in the upper mount to assist you in aligning mount with the bolt holes in the body.
Figure 19

As you put the assembly in place, this body-mounted stud threads through a hole in the upper mount to assist you in aligning mount with the bolt holes in the body.

Replace the three upper mount bolts and their washers.
Figure 20

Replace the three upper mount bolts and their washers.

Tighten the three 16mm bolts to 48 ft-lbs.
Figure 21

Tighten the three 16mm bolts to 48 ft-lbs.

Position the bottom of the shock so that you can secure it to the lower control arm.
Figure 22

Position the bottom of the shock so that you can secure it to the lower control arm.

Use a new nut and bolt to secure the shock.
Figure 23

Use a new nut and bolt to secure the shock. Note that I've put the bolt to the front side of the arm rather than the rear to make it easier to remove the bolt in the future. On this side its removal won't be obstructed by the rear control arm.

24
Figure 24

Tighten the bolt to 74 ft-lbs

Remove the plastic protective caps from the upper control arm ball joints.
Figure 25

Remove the plastic protective caps from the upper control arm ball joints.

Place some anti-seize lubricant on the ball joints to assist in their installation and potential removal later.
Figure 26

Place some anti-seize lubricant on the ball joints to assist in their installation and potential removal later. Note the semi-circular groove around the post of each ball joint. The pinch bolt rests in this groove when it is installed--you'll need to get that groove deep enough into the upright that the pinch bolt can pass through.

Align the ball joints with the holes in the upright.
Figure 27

Align the ball joints with the holes in the upright. You will need to manipulate the ball joints themselves to get the metal posts of the joints to align perfectly with the holes. Once you get them into position, use a rubber mallet to tap the joints down into the holes in the uprights. It's a tight space to work in. Your goal is to get the end of the metal post of the ball joint roughly flush with the underside of the hole in the upright to allow the pinch bolt to line up with the semi-circular groove in the ball joint.

Once the ball joints are pushed far enough into the upright, you can pass the pinch bolt through the upright from the rear and secure it with a 16mm nut attached to the front of the upright.
Figure 28

Once the ball joints are pushed far enough into the upright, you can pass the pinch bolt through the upright from the rear and secure it with a 16mm nut attached to the front of the upright. Use some anti-seize lubricant and new hardware and torque the nut and bolt to 30 ft-lbs.

As mentioned earlier, it may be easier to perform the final torque application for the upper control arm bolts without the wheel and tire in the way.
Figure 29

As mentioned earlier, it may be easier to perform the final torque application for the upper control arm bolts without the wheel and tire in the way. If you jack the front suspension up to an approximation of the resting ride height, you can access these bolts like so - but you probably won't be able to get a torque wrench in there.

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Comments and Suggestions:
JUNKERAVANT Comments: HA! HA! you were damned lucky on that pinch bolt! I've seen many use the flame wrench on it and then they had to hammer the entire assembly some good whacks with a heavy hammer. Another time I saw a mechanic use a air hammer vibrating the entire assembly to loosen the bolt. Lots of rust came out that way.
April 27, 2016
  Followup from the Pelican Staff: AGREED! They can be terrible to get out. - Nick at Pelican Parts  
ventogt Comments: which year audi control arm is compatible with a 1996 vw jetta? heard that the audi version gives more cushion vs vw's version
April 11, 2015
  Followup from the Pelican Staff: Don't know, never heard of this.

Give our parts specialists a call at 1-888-280-7799. They can figure out what part or repair kit you need.
- Nick at Pelican Parts
 
Audiwan Kenobi Comments: Once again I feel that I'm ready to do this job because of PELICAN AUTO!!!!...thanks!
March 26, 2015
  Followup from the Pelican Staff: Thanks for the feedback. Glad we could help.
- Nick at Pelican Parts
 
Jim Comments: I have been told that climate issues such as summer heat can erode the rubber containing the grease for these joints causing the need to replace the entire joint. . Is this an accepted opinion? And if so in an area such as central Florida for a normally driven SUV Ford Explorer what would you estimate is the normal time between replacements you would anticipate?

Thankyou

January 23, 2014
  Followup from the Pelican Staff: Can't offer insight on Fords. The grease in all non-serviceable ball joints seems to wear away over time. - Nick at Pelican Parts  
Tommy V Comments: Hello, So I followed this step by step, everything went nice and smooth. Got on the road and had to pull my steering wheel all the way to the right to keep the car straight, plus just over all doesnt feel right. From my understanding replacing just the upper's you dont need an alignment. What could have thrown it out of wack?
August 30, 2013
  Followup from the Pelican Staff: Did you install the tie road ends upside down? I have seen this done by accident before. Double check they are installed with the tie rod end ball joints pointing up. I normally suggest aligning a vehicle after this repair due to differences in manufacturing tolerance and distrubing the strut mount.- Nick at Pelican Parts  

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