Are the trailing arms “torque in final position?”

[kolosy]

Newtis has both, depending on the thread? https://www.newtis.info/tisv2/a/en/e...struts/5fOkTQS

not sure I understand the need — those bushings don’t need to be preloaded, do they?

[Muzz258]

The usual advice on the forum is to "torque in final position". If you don't, you'll end up putting a twisting moment on the rubber bushing when the car is lowered to the ground.

If you are working on axle stands, you need to put a jack under the trailing arm and lift it until it just raises above the jack stand on that corner of the car. Then torque the bolts.

[kolosy]

The usual advice on the forum is to "torque in final position". If you don't, you'll end up putting a twisting moment on the rubber bushing when the car is lowered to the ground.

If you are working on axle stands, you need to put a jack under the trailing arm and lift it until it just raises above the jack stand on that corner of the car. Then torque the bolts.

meaning the trailing arms should be roughly parallel to the ground? It’s on a quick jack right now, with the subframe off and on a transmission jack.

[solimans]

Not at a certain angle but bearing the weight of the car...

After you have it all back together.

I guesstimated the angle because I was not sure I would have access


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[kolosy]

Not at a certain angle but bearing the weight of the car...

After you have it all back together.

I guesstimated the angle because I was not sure I would have access


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how is that even doable without a 4 post lift? drop it onto bricks or something?

also -- since my subframe is out at the moment, i can't speak to the clearance up there once it's in, but i can't imagine it being good.

[solimans]

how is that even doable without a 4 post lift? drop it onto bricks or something?

also -- since my subframe is out at the moment, i can't speak to the clearance up there once it's in, but i can't imagine it being good.

Yes on to ramps for example. Or put a block of wood on a floor jack and lift the c. arm

I hear you on the clearance. I can’t say because i lifted my arms and torqued them while the whole assembly was on a trans jack...


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[kolosy]

Yes on to ramps for example. Or put a block of wood on a floor jack and lift the c. arm

I hear you on the clearance. I can’t say because i lifted my arms and torqued them while the whole assembly was on a trans jack...


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so that's not "bearing the weight of the car" then... i assume the only thing the car's weight can do other than rotate the TAs is possibly shift the bolt + RTAB upward if there's any clearance to do so. Given how tight that clearance is, I'd expect the rotational position of the TA to be most of the concern then..

[solimans]

so that's not "bearing the weight of the car" then... i assume the only thing the car's weight can do other than rotate the TAs is possibly shift the bolt + RTAB upward if there's any clearance to do so. Given how tight that clearance is, I'd expect the rotational position of the TA to be most of the concern then..

Correct. That is how I did it (lifted the arms). Others may be able to comment on the clearance

In Bentley and in TIS (iirc) it does say to have it on the ground


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[kolosy]

Correct. That is how I did it (lifted the arms). Others may be able to comment on the clearance

In Bentley and in TIS (iirc) it does say to have it on the ground


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I just did them with lifted arms, and omg i cannot imagine getting a wrench in there with the subframe fully in. i could barely finagle it in there with a solid 6" of clearance above.

[solimans]

I just did them with lifted arms, and omg i cannot imagine getting a wrench in there with the subframe fully in. i could barely finagle it in there with a solid 6" of clearance above.

I remember feeling the same way at the time...


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[PbFut]

If you are using rubber TA bushings you for sure want to lift the arm into a normal ride height position before the final torquing down of the bushing bolt. If you don't the bushing will be in place with the "normal" position being a fully extended arm. That means the bushing rubber will always be in a twisted state unless the arm is in a full down position which is almost never. Remember the rubber is connected to the inner and outer sleeve on a rubber bushing. So you want the sleeves and rubber in a untwisted state at normal ride height. That allows the bushing to be a neutral as possible through the arc. Urethane bushings don't have this issue as the inner sleeve rotates inside the urethane. Thats why you grease the urethane so it doesn't squeak.

[kolosy]

If you are using rubber TA bushings you for sure want to lift the arm into a normal ride height position before the final torquing down of the bushing bolt. If you don't the bushing will be in place with the "normal" position being a fully extended arm. That means the bushing rubber will always be in a twisted state unless the arm is in a full down position which is almost never. Remember the rubber is connected to the inner and outer sleeve on a rubber bushing. So you want the sleeves and rubber in a untwisted state at normal ride height. That allows the bushing to be a neutral as possible through the arc. Urethane bushings don't have this issue as the inner sleeve rotates inside the urethane. Thats why you grease the urethane so it doesn't squeak.

the reason for preloading fixed bushings makes sense to me, just looking at the TA ones (vs the FCAB, for example) it wasn't obvious what was going to grab the bushing, since the bolt spins freely inside it. I'm assuming that the issue is that the mounting bracket gets compressed slightly when it's torqued to spec, pinning the bushing at the edges?

[PbFut]

Correct. You would have metal shavings in the area over time if the bolt spun inside that bushing.