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Control Arm Install Question (Rear Control Arms)

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Old 08-07-10, 09:43 AM
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Lexus082
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Default Control Arm Install Question (Rear Control Arms)

I am planning to remove and replace the rear control arms. However, there's one problem I need to figure out before I can start. The control arm bolts must be torqued down with the car's weight resting on the suspension (compressing the spring). If you torque the control arm bolts while the car is in a raised position (ie: using a jack) then you will destroy the control arm bushings.

The problem is when you have the car sitting completely on the ground how are you suppose to torque down the control arm bolts. I could see it being possible to torque down the lower control arm bolts, but the upper control arm bolts? I just dont see how to properly tighten these bolts up to avoid destroying the bushings. Hopefully I've explained this well enough and I really hope someone has the answer.
Old 08-07-10, 10:02 AM
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Originally Posted by Lexus082
I am planning to remove and replace the rear control arms. However, there's one problem I need to figure out before I can start. The control arm bolts must be torqued down with the car's weight resting on the suspension (compressing the spring). If you torque the control arm bolts while the car is in a raised position (ie: using a jack) then you will destroy the control arm bushings.

The problem is when you have the car sitting completely on the ground how are you suppose to torque down the control arm bolts. I could see it being possible to torque down the lower control arm bolts, but the upper control arm bolts? I just dont see how to properly tighten these bolts up to avoid destroying the bushings. Hopefully I've explained this well enough and I really hope someone has the answer.
I do know exactly what you mean. If you can't get the car up on all fours with enough clearance underneath (use four ramps and some extra blocking maybe), then you should be ok if you can just tighten it up enough to drive straight to the alignment shop and have them loosen and retorque to spec while it's up on the rack.
Old 08-07-10, 03:56 PM
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BartleDoo
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If the inner bushing sleeves are freshly greased should it really cause any torsion on the bushings at all?
Old 08-07-10, 04:56 PM
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shouldnt matter...
Old 08-15-10, 12:10 PM
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Lexus082
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In the lexus repair manual it explains that once you have all the bolts finger tight your suppose to put the wheel(s) back on and bounce the vehicle up and down several times to stablize the suspension.

Then your suppose to jack it back up and remove the wheel and support the rear axle carrier with a jack and then torque everything down.

My question is do you torque the suspension bolts while the car is in a raised position such as on a rack or resting on the ground?

I thought you were suppose to torque the bolts down while the car is on the ground with its weight fully resting on the suspension evenly, so the geometry is correct between the control arms and the chassis.

To me it seems if you torque down the suspension while its on a rack "hanging" freely, its going to over extend the bushings when you put the car back on the ground causing premature failure. Which is the correct way?
Old 08-15-10, 09:15 PM
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I'm not sure what the correct way is; however instead of putting the full weight of the car on a wheel, you can always use a jack stand under the control arm to simulate full weight while still giving you access to the bolts.
Old 08-16-10, 08:50 AM
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To the best of my knowledge . . .

If the bushing are made of rubber that is attached/bonded/adhered to the inner sleeve, then you'll want them torqued in the normal operating position, NOT drooped!

If your bushing are NOT bonded to the inner sleeves, then yes, providing they are lubed, they should slip and adjust regardless of the attitude of the suspension when torqued.

The inner sleeve is what becomes immobile once torqued.
Old 08-16-10, 04:31 PM
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evileagle
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Does this apply to the front control arms as well? I changed out my lower front control arms and I didnt tighten them down when they were on the ground, but on the air....
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