Lower Control Arm Rebuild- E4WD, Notes and Observations
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Lower Control Arm Rebuild- E4WD, Notes and Observations
[updated:LAST EDITED ON 02-Oct-02 AT 04:53 PM (EST)]Rebuilding notes and observations for future reference concerning the all wheel drive lower control arm assembly.
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1.) A rebuild was performed in conjuction with replacement of the power steering rack and pinion as both lower control arms must be removed to access the steering rack.
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2.) The vehicle was a 1991 Aerostar E-4WD, 4.0l with 209,000 miles registered.
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3.) REMOVAL: Steps employed in removal were essentially the same outlined in both the Ford and Chilton repair manuals. The notable exception concerned releasing the lower ball joint from the spindle. The manuals both use a Pittman arm ball joint remover. The surface area surrounding the ball joint is too small to use a regular 2 or 3 jawed puller. There is a puller arm access slot built into both the thin sheet metal brake shield and the spindle. In my case however, the two openings did not match up and the brake shield was slightly higher than the spindle. The Pittman puller arm would have severely distorted the sheet metal if used to remove the lower ball joint. The options were to either completely dismantle the bearing hub and remove the brake shield or use an alternative removal method. Two alternatives were tried, both with success:
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A.) A ball joint/tie rod "pickle fork" was inserted between the ball joint stem and spindle. A single blow with a 3# mallet was sufficient to release the ball joint. The disadvantage to this method is the rubber boot will be destroyed in the process.
B.) The second joint was removed by backing off the retainer nut until just flush with the outer end of the ball joint stem. A single sharp blow with a 3# mallet cause the joint to separate easily. The retainer nut could stilll be removed with finger pressure alone.
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4.)Notes: both ball joints despite the high mileage were in excellent condition. Before removal, there was no detectable looseness or wear when tested, both with the coil spring in place and after the coil spring had been removed. The excellent condition of the lower ball joint is in contrast to the upper joints which had both been replaced earlier due to severe wear.
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5.) Removing the ball joint involves removal of a spring clip retainer and pressing out the old joint. This is not covered in the manuals as they recommend replacement of the entire control arm. While pressing out the old ball joint (as well as the rubber bushings) is feasible, it is difficult due to the shape of the control arm. Mostly featuring compound curves and angles, making it very difficult to provide a level, stable platform for the press to operate against. The amount of force required to separate the ball joint from control was excessive, resulting in a violent, explosive separation. Replacement of the new joint was so much easier than removal, in hindsight, it must be considered whether the design of the control arm actually causes the control arm to bind the ball joint when being pressed out. A recommendation would be to try to drive the old ball joint out with a hammer and punch before trying to press out the joint. I was unable to test this therory as both joints were pressed out, each with the same explosive result. Only after observing how easily the new joints could be driven back in place, did I wonder about the press causing the problem. The new joints were measured with a micrometer against the old to ensure they were not undersized. Both were exactly the same dimensions.
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6.) The lower control arm utilizes two different sized rubber bushings, both a rubber/metal composite design, fairly large in size (1.5 to 1.75 inches in diameter). These too, are pressed into place and again, due to the design of the control arm, are very difficult to remove. Each bushing is held in place by two 'rings' at the rear of the control arm. While these rings are tremendously strong in one axis, they are very weak in the lateral axis. To understand this, extend and slightly separate the index and second fingers of your right hand. Now, curl these two fingers as if around an imaginary bar. Your fingers have enough strength to support your weight if you did hang from a bar, however, a child could force your two fingers together, as you have very little strength in that direction.
These bushings are held in place in a similar manner and when you apply force to try to remove the bushing, the two "fingers" want to collapse together. You can easily ruin the lower control arm if you inadvertently bend these two "fingers" holding the bushing. It is for this reason, I believe, the manuals suggest replacing the control arm rather than attempt removal. I was able to remove them but it required lots of aggravation and cobbling up special support pieces to fit between the "fingers" to prevent their collapse.
Now for the good news. After 200,000+ miles, these bushings were in perfect condition and did not need to be replaced. I could find no appreciable wear compared to the new ones. I only replaced them because I had already purchased new ones, not because they need replaced.
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7.) Note: When removing the coil springs, TWO spring compressors are the ideal method. Once that spring is compressed and out of the car, it is very difficult to find a way to hold the spring while you remove the internal style compressor. If you do succeed, you then must re-compress the spring to put it back in, a total of 4 manipulations per spring. A coil spring under compression is an extremely dangerous character and should be treated as if it were a high explosive, i.e. handled as little as possible. I feel the small cost of second compressor is minimal compared to the damage a spring can inflict. You can purchase a decent internal style compressor at Harbour Freight for around $15, less if on sale.
Respectfully submitted
10-02-02
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1.) A rebuild was performed in conjuction with replacement of the power steering rack and pinion as both lower control arms must be removed to access the steering rack.
>
2.) The vehicle was a 1991 Aerostar E-4WD, 4.0l with 209,000 miles registered.
>
3.) REMOVAL: Steps employed in removal were essentially the same outlined in both the Ford and Chilton repair manuals. The notable exception concerned releasing the lower ball joint from the spindle. The manuals both use a Pittman arm ball joint remover. The surface area surrounding the ball joint is too small to use a regular 2 or 3 jawed puller. There is a puller arm access slot built into both the thin sheet metal brake shield and the spindle. In my case however, the two openings did not match up and the brake shield was slightly higher than the spindle. The Pittman puller arm would have severely distorted the sheet metal if used to remove the lower ball joint. The options were to either completely dismantle the bearing hub and remove the brake shield or use an alternative removal method. Two alternatives were tried, both with success:
>
A.) A ball joint/tie rod "pickle fork" was inserted between the ball joint stem and spindle. A single blow with a 3# mallet was sufficient to release the ball joint. The disadvantage to this method is the rubber boot will be destroyed in the process.
B.) The second joint was removed by backing off the retainer nut until just flush with the outer end of the ball joint stem. A single sharp blow with a 3# mallet cause the joint to separate easily. The retainer nut could stilll be removed with finger pressure alone.
>
4.)Notes: both ball joints despite the high mileage were in excellent condition. Before removal, there was no detectable looseness or wear when tested, both with the coil spring in place and after the coil spring had been removed. The excellent condition of the lower ball joint is in contrast to the upper joints which had both been replaced earlier due to severe wear.
>
5.) Removing the ball joint involves removal of a spring clip retainer and pressing out the old joint. This is not covered in the manuals as they recommend replacement of the entire control arm. While pressing out the old ball joint (as well as the rubber bushings) is feasible, it is difficult due to the shape of the control arm. Mostly featuring compound curves and angles, making it very difficult to provide a level, stable platform for the press to operate against. The amount of force required to separate the ball joint from control was excessive, resulting in a violent, explosive separation. Replacement of the new joint was so much easier than removal, in hindsight, it must be considered whether the design of the control arm actually causes the control arm to bind the ball joint when being pressed out. A recommendation would be to try to drive the old ball joint out with a hammer and punch before trying to press out the joint. I was unable to test this therory as both joints were pressed out, each with the same explosive result. Only after observing how easily the new joints could be driven back in place, did I wonder about the press causing the problem. The new joints were measured with a micrometer against the old to ensure they were not undersized. Both were exactly the same dimensions.
>
6.) The lower control arm utilizes two different sized rubber bushings, both a rubber/metal composite design, fairly large in size (1.5 to 1.75 inches in diameter). These too, are pressed into place and again, due to the design of the control arm, are very difficult to remove. Each bushing is held in place by two 'rings' at the rear of the control arm. While these rings are tremendously strong in one axis, they are very weak in the lateral axis. To understand this, extend and slightly separate the index and second fingers of your right hand. Now, curl these two fingers as if around an imaginary bar. Your fingers have enough strength to support your weight if you did hang from a bar, however, a child could force your two fingers together, as you have very little strength in that direction.
These bushings are held in place in a similar manner and when you apply force to try to remove the bushing, the two "fingers" want to collapse together. You can easily ruin the lower control arm if you inadvertently bend these two "fingers" holding the bushing. It is for this reason, I believe, the manuals suggest replacing the control arm rather than attempt removal. I was able to remove them but it required lots of aggravation and cobbling up special support pieces to fit between the "fingers" to prevent their collapse.
Now for the good news. After 200,000+ miles, these bushings were in perfect condition and did not need to be replaced. I could find no appreciable wear compared to the new ones. I only replaced them because I had already purchased new ones, not because they need replaced.
>
7.) Note: When removing the coil springs, TWO spring compressors are the ideal method. Once that spring is compressed and out of the car, it is very difficult to find a way to hold the spring while you remove the internal style compressor. If you do succeed, you then must re-compress the spring to put it back in, a total of 4 manipulations per spring. A coil spring under compression is an extremely dangerous character and should be treated as if it were a high explosive, i.e. handled as little as possible. I feel the small cost of second compressor is minimal compared to the damage a spring can inflict. You can purchase a decent internal style compressor at Harbour Freight for around $15, less if on sale.
Respectfully submitted
10-02-02
