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Discussion Starter #1
I've just installed new LCA's and strut bushings (yep, OEM Ford). The car is still up on stands and I wondered about torquing down the shock bolt and LCA cam bolt nuts with the wheels off.

I don't currently have a pair of ramps, so is there a reason why I couldn't just lift the relevant side of the vehicle off the stand at the LCA near the ball joint and tighten these nuts?
Isn't that essentially the same thing as mounting the wheels and lowering the car to do it, since the knuckle/shock/spring are supporting the body either way and would thus prevent bushing wind-up just as well as when done with wheels on and lowered?

Btw, I jacked the knuckle assembly in an early attempt to press in the new ball joint taper so that I could tighten the new Moog crimp nut -- that didn't work, even lifted the vehicle off the stand, so I ended up using the OEM nut to pull up the taper tight, then removed that nut and the Moog nut went on no prob after that.

Anyway, it's SO much easier to get at these nuts and see what I'm doing (such as aligning my pre-removal cam marks) with the wheels off and the car lifted.

Is this a no-no?
 

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I've torqued these nuts by putting a jack under the LCA (under the ball joint, just like you're saying) and jacking it up just enough to get the weight of the vehicle off the jack stands. Never had an issue doing it this way and I've done it to 3 cars now, just make sure your jack stands are ready to go in case the unexpected happens. :)
 

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Jacking the LCA inward of the lower ball joint changes the leverage ratio, you will see that while it does compress the spring and shorten the front shock some, it's not at all the same as when the car rests on the wheel itself (which takes the weight out at the end of the LCA at the lower BJ.)

The purpose behind tightening the control arm pivot bolts, upper and the lower one as well as the lower shock mount on some cars / PUs like my '07 F150 is because the inner sleeve and rubber bushing and outer sleeve are molded as a unit and the rubber flexes instead of twisting on the inner bushing. That way the rubber isn't squeaking so much and wearing out where it rubs the sleeve 'cause it ain't rubbing ... it's "flexing". Tightening the bolt when the suspension is loaded the same as at rest on the wheels "parks" the bushing in a neutral position so it's not "parked" in a perpetual state of "twist".

It'll last longer that way.
 

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^^^ True dat. The suspension seems to compress more before lifting off the jack stands the further out on the lower arm you jack it up. Truth be told, most of the time I do it a few inches from the knuckle since it is much more convenient. It is better than nothing :)
 

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The suspension seems to compress more before lifting off the jack stands the further out on the lower arm you jack it up.
Exactly. ;)

Look at the LCA as a "lever", the forces working both ways and the pivot. The inner pivot is the pivot. You have a handle and are pulling up to compress a spring against a wall. The longer the lever, the easier you can pull up to compress the spring.

The car's weight pushing down (gravity pulling it) is the same as you pulling up on that lever. The lever is the length between the lower ball joint center and the inner pivot. Move the lower shock mount in and it will seem easier to compress, move it out towards the BJ and it gets harder to compress or the better it supports the car's weight.

Imagine a 8 foot long 2x4 mounted to a hinge on the wall 3 feet off the floor. You are holding the other end level. Let's say you can hold up 200 pounds. If Sally sits astride that 2x4 in the center, as long as she weighs 400 or less, you can hold your end up. If she comes up real close to you, she's gonna feel heavier. Sitting on that 2x4 right at your hand, she only has to weigh 200 to max you out. Slide her back towards the wall and she can weigh a whole lot more and you can still hold her up.
Sally was a good size girl, and like the song said ....
"Sally was a good ole girl,
Sally was a good ole girl,
No matter what the request,
She gave it her best,
Sally was a good ole girl ...."
:D
 

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Discussion Starter #6 (Edited)
Well, I finished the job yesterday before catching the latest replies.
The jack point was just barely inside the ball joint, right next to it in fact (not under it as I didn't want to risk crushing the cup).

I've lowered the car but haven't taken it for a test drive.

I'm wondering how much damage I'll do to the new bushings if I only drive it far enough (on smooth roads) to buy some ramps.

I suppose I might be able to get at the nuts with wheels turned fully to their extremes. I'll likely have to use a socket extension and one long enough from the shock bolt may not let my torque wrench clear the body -- I dearly hate the thought of trying to use one of my socket u-joints for this.
That shock bolt took a fair amount of effort with wheels off (145 lb-ft.), and I'm pretty sure I won't be able to do it at ground clearance level if I have to get under the vehicle.

Is the difference in movement of the knuckle with wheels down vs. how I just did it enough to make a real world difference to bushing life; not theory but proven out by physical long term tests? Is the difference in bushing/sleeve rotation 3°? 30°? More? I doubt anyone has bothered measuring the actual difference, since most probably do the job in the prescribed fashion on alignment lifts or at least ramps (even though ramps also change the relative angle, which slightly modifies the results), but if anyone has eyeballed it, please offer up a rough estimate.

I'm wondering if it's enough to matter, though. These LCA bushings outlasted the ball joints, so if the set I just installed will last only as long as the ball joints themselves, I'll buy new LCA's which include new bushings.

I'm assuming it'd be an unwise move to put the lug nuts on and lift by the rotors or the lug bolts. The lugs support the weight normally, of course, but that's all 5 of them in unison, so 2 probably couldn't handle the load (plus me bearing down to torque the nuts). :beek:
 

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Discussion Starter #7
I ended up loosening and retorquing the nuts with wheels down before driving it.
I got the shock nuts to spec, but there was insufficient room for my wrench on the cam nuts.
I got them almost done with a shorter wrench and spec'd them after jacking the car up with wheels off the ground to give my torque wrench clearance. The cam nuts will be redone by the alignment tech anyway, so I'm not too concerned about them.
 

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If you get them good'n'tight with the cars wheels resting on the ground so the inner sleeve is gripped tight enough to not slip ...
... then you can jack and block with stands and get under there and pull the nuts to final torque values if ramps aren't handy.

It's how I did some of the nuts on my '07 F150 recently.

You probably didn't hurt them driving short term, it'ld be same as driving with overloaded or broken spring or with 4 FB players in the car.
 

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Yup. I like to tighten them with tension on the control arm. Driving onto ramps will have the suspension at its normal rest "height"
 
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