LCA bushings when the front end is jacked up

[bc3j]

When the suspension drops to its limit when the car is jacked up or on a lift, do the LCA bushing suffer any long term damage?

[RUNCHARGER]

Yes: They are twisted out of shape, they are likely to crack.

[bc3j]

Thanks.
I guess it would be prudent to jack under the lower control arm (as stated in the FSM) when changing a wheel. I have been using the lower control arm jack point now.  Just don't want to stress that bushing.

[ply64post]

When the suspension drops to its limit when the car is jacked up or on a lift, do the LCA bushing suffer any long term damage?

I don't know all the answers, I would not think there would be any damage when doing normal service work.
There are many lifts used today that  the suspensions hang while being serviced. ( Frame support lifts. ) Even in emergencies you would use a bumper jack to change a tire along the road. I have worked as a technician for 50+ years and never seen any damage on bushings while doing service work. If that was the case there would be a lot of vehicles with damaged suspensions.           

[JS29]

I would think if left for a long period of time (weeks or months) it would be a concern. 

[GoodysGotaCuda]

I would think if left for a long period of time (weeks or months) it would be a concern. 

Yep

[ply64post]

I would think if left for a long period of time (weeks or months) it would be a concern. 

Yep

Yes I would agree on long time storage, just not for service work.

                                                 Jeff

[bc3j]

I appreciate the info. Going to change wheels and the car has the potential to be in the air for several hours while I transport the wheels back and forth. LCA bushing where changed two years ago and I didn't want them damaged during the process. Thanks

[RUNCHARGER]

Two hours is no big deal. I was thinking several months as being long term.

[IRON MAN]

If the e body is on a lift and the suspension hanging with the wheels bolted on, I can understand how this will twist the LCB rubber bushings and cause damage. If the wheels are removed the LCB bushings should be fine? I ask this because a friend has had his 70 Challenger on a single post lift with the suspension hanging for three months now. With the wheels off it seems the lower control arm bushings would be less likely to twist enough to cause damage. Steel wheels with tires are very heavy. He is not a member here so I will ask him to read the thread.

[GoodysGotaCuda]

If the e body is on a lift and the suspension hanging with the wheels bolted on, I can understand how this will twist the LCB rubber bushings and cause damage. If the wheels are removed the LCB bushings should be fine? I ask this because a friend has had his 70 Challenger on a single post lift with the suspension hanging for three months now. With the wheels off it seems the lower control arm bushings would be less likely to twist enough to cause damage. Steel wheels with tires are very heavy. He is not a member here so I will ask him to read the thread.

Wheels on or off will make no difference when suspending a car on a lift. The torsion bars are still going to relax and let the suspension sit on the upper control arm bump stop. Wheels on, or not.

That relaxation is twisting any suspension bushing which is torqued at ride height.


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[bc3j]

I guess to play it safe, I'll jack under the lower control arm (per FSM) and replace the wheel with the spare. Then go to the other side and jack under the lower control arm and remove that wheel and have it remain on the jack, backed up by a jack stand, until I get back from the shop with the new wheels. I don't think I'll be twisting the bushings this way. If this was simply an up and down operation I wouldn't be worried about it, but when dealing with third party schedules it can sometimes takes longer than expected. Hope I'm not being overly paranoid over these bushings.

[IRON MAN]

[/quote]

Wheels on or off will make no difference when suspending a car on a lift. The torsion bars are still going to relax and let the suspension sit on the upper control arm bump stop. Wheels on, or not.

That relaxation is twisting any suspension bushing which is torqued at ride height.


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[/quote]
Two questions: Does it matter if the control arms have polyurethane bushings when the suspension is hanging ?
                       Does this apply if the control arm's bolts are loosened before leaving the vehicle on a lift for a long
                       time, with the suspension hanging? Later, lower vehicle and tightened bolts.

[GoodysGotaCuda]

Two questions: Does it matter if the control arms have polyurethane bushings when the suspension is hanging ?
                       Does this apply if the control arm's bolts are loosened before leaving the vehicle on a lift for a long
                       time, with the suspension hanging? Later, lower vehicle and tightened bolts.

Loosening the upper control arm bolts and the lower pivot bolt will certainly relieve the concern about damaging the bushings. You'll need to retighten them once lowered again. I can't say one way or the other on poly bushings making a difference or not.

[jt4406]

 

Loosening the upper control arm bolts and the lower pivot bolt will certainly relieve the concern about damaging the bushings. You'll need to retighten them once lowered again       

REALIGN vehicle AND retighten.