question about the upper A-arms...

[supraguy@aol]

I was reinstalling them today, and the TSRM says to torque the A-arm pivot bolts once the suspension has the car's weight on it. I guess I'm wondering- do the A-arms actually move up and down in their suspension travel by pivoting along the pivot bolt, or do they simply move by flexing the bushings?

 

[rayall01]

I was reinstalling them today, and the TSRM says to torque the A-arm pivot bolts once the suspension has the car's weight on it. I guess I'm wondering- do the A-arms actually move up and down in their suspension travel by pivoting along the pivot bolt, or do they simply move by flexing the bushings?

They flex the bushings. If you don't torque them at ride height, you run the risk of tearing the bushings, due to over extension and that won't be a good thing. It's the same thing with the lower control arm as well. The TSRM doesn't give instructions just for the fun of it.

 

[supraguy@aol]

Well, that's how it seemed to work to, yes. As for tearing the bushings, I'm surprised that I haven't- After replacing the springs/ struts years ago, I'm sure I torqued all of the A-arms down at a fully-extended position. However- the bushings looked fine when I checked them.
Now what about aftermarket bushings, like the Energy Suspension items? Being that they're a tougher material, do those bushings still work the same way- by flexing? Or, do they rotate within the A-arms themselves?

 

[rayall01]

Well, that's how it seemed to work to, yes. As for tearing the bushings, I'm surprised that I haven't- After replacing the springs/ struts years ago, I'm sure I torqued all of the A-arms down at a fully-extended position. However- the bushings looked fine when I checked them.
Now what about aftermarket bushings, like the Energy Suspension items? Being that they're a tougher material, do those bushings still work the same way- by flexing? Or, do they rotate within the A-arms themselves?

In my post, I said risk, it's not a lock that you'll tear them. IIRC about aftermarket bushings, it's recommended that you use lubricant during installation to prevent noisy operation, which would indicate to me that some rotation could occur, but I can't say for certain.

 

[supraguy@aol]

Yes, got it- risk. I'm just saying I guess I got lucky, as the first time I removed all the upper A-arms and improperly torqued them was about 12 years and 140,000 miles ago. And yeah- I think you're right about the aftermarket items, because the inner sleeves look to be what locks up tight against the suspension pivot mount, meaning the bushings are free to rotate, which seems like a better way to do it anyway.

 

[Poodles]

No, they don't twist the bushing....

It's to prevent unnecessary binding that would cause preload and issues with ride height...

 

[rayall01]

No, they don't twist the bushing....

It's to prevent unnecessary binding that would cause preload and issues with ride height...

While I may be wrong about the Supra's bushings, a blanket statement like that seems wrong as well.

http://findarticles.com/p/articles/mi_qa3828/is_200306/ai_n9257837/

This article shows that some types of bushings are indeed bonded to the metal, and as such could fail due to excessive twisting. Are we sure about the Supra's bushings? How were they manufactured? Are they shot, or hot bonded? My statement was a blanket one as well, and for that I apologize.

 

[IJ.]

You're actually correct the Supra Bushes are bonded and the long travel of the stock suspension requires them to be locked down while at ride height to prevent tearing the centres out.

We mods are wrong from time to time don't hold it against us, I welcome corrections as long as it's done without malice.

 

[rayall01]

I was nice about it, wasn't I?:icon_bigg

 

[Poodles]

See what I get for looking at the aftermarket bushings :3d_frown:

 

[Asterix]

More than one person on my350z.com has had bushings fail after lowering their car because they didn't re-center the bushing. The one that fails is a front lower bushing and is load-bearing, so it gets much more abuse than the upper ones. (I'd post a link, but the board is down right now...)

You'll get away with the uppers not being centered at ride height for much longer than the front lower ones. Also, the uppers are pretty squishy...

Asterix

 

[rayall01]

More than one person on my350z.com has had bushings fail after lowering their car because they didn't re-center the bushing. The one that fails is a front lower bushing and is load-bearing, so it gets much more abuse than the upper ones. (I'd post a link, but the board is down right now...)

You'll get away with the uppers not being centered at ride height for much longer than the front lower ones. Also, the uppers are pretty squishy...

Asterix

It ain't that difficult to tighten the bolt at ride height, so why even try to get away with it?