Author Topic: Achieving "Static Laden Condition" For Wishbone Bushing Torque  (Read 389 times)

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Offline thehackmechanic

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Achieving "Static Laden Condition" For Wishbone Bushing Torque
« on: Monday,December 23, 2019, 06:51:16 PM »
I'm buttoning up the front end rebuild of my TCS and need to torque down the wishbone bushings. I'm well aware that this shouldn't be done while the vehicle is in the air and the wishbones are drooping. The manual says to "Leave all nuts slack until vehicle is in static laden condition and then tighten to the recommended torque figures outlined in the Technical Specifications section of this manual." The "static laden condition" is 150 pounds in each seat. Unfortunately, I have no easy way to do this, and even if I did, I can't see how to reach the nuts and bolts with the vehicle weighted down and on the ground.

I do, though, have a mid-rise lift. Is it sufficient to pick the vehicle up on the lift, put a set of blocks under the front wheels, and lower the front wheels onto the blocks, compressing the front springs while the rear wheels are still in the air? That'll compress the springs more than just the weight of the car would, and also allow me to get under it to torque things down. I realize it's not exact, but do you think that, like hand grenades and horse shoes, it's close enough?

--Rob
'74 TCS, 24k miles, up and running after 40 years
'72 BMW 2002tii
'72 BMW Bavaria
'73 BMW 3.0CSi
'79 BMW Euro 635CSi
'99 BMW Z3M Coupe
'99 BMW Z3
'96 Winnebago Rialta

Five books available on Amazon (www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias%3Daps&field-keywords=rob+siegel)

Offline Pfreen

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Re: Achieving "Static Laden Condition" For Wishbone Bushing Torque
« Reply #1 on: Monday,December 23, 2019, 07:01:30 PM »
Yes

Offline BDA

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Re: Achieving "Static Laden Condition" For Wishbone Bushing Torque
« Reply #2 on: Monday,December 23, 2019, 07:18:28 PM »
As Pfreen says, that is fine.

The reason you are supposed to tighten the fulcrum pins with the suspension at ride height is because the outside of the bushings are locked on the suspension arms and the inside of the bushings is locked by the nuts on the fulcrum pins. If the suspension rotates too much, the rubber will tear. By tightening the suspension at ride height, that neither the movement in the suspension up nor down is enough to tear the rubber in the bushings.

Offline jbcollier

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Re: Achieving "Static Laden Condition" For Wishbone Bushing Torque
« Reply #3 on: Monday,December 23, 2019, 07:57:00 PM »
It is not good practice to load a lift that way.  I agree that a Europa is so light you are unlikely to kill yourself, but, why take the risk?  No, I'm not being too cautious.  I have seen cars fall off lifts and I lost a neighbour that way -- curiously also working on a Lotus.

Put the car on the ground.  Set the handbrake or block the rear wheels.  Jack up the front of the car and put it on stands or ramps.  Do not use random piles of stuff that can slip out of place.  Do not use concrete blocks.  Once you know it's safe, bounce on the front end to settle it.  Then tighten the suspension fittings.  You may be off by an inch or so but you are close enough for the bushes not to be overstressed by full suspension travel.

Offline Certified Lotus

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Re: Achieving "Static Laden Condition" For Wishbone Bushing Torque
« Reply #4 on: Tuesday,December 24, 2019, 03:31:24 AM »
I had no problem tightening these nuts while the car was on the ground. I used socket extensions for the front and back and was able to tighten to spec. Agreed a long extension will throw off the torque wrench setting, but not by much.

And I’m in JB’s camp regarding blocking the car at height. No way. I value my life and limbs.

Offline thehackmechanic

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Re: Achieving "Static Laden Condition" For Wishbone Bushing Torque
« Reply #5 on: Tuesday,December 24, 2019, 04:56:20 AM »
Got it, thanks all.
'74 TCS, 24k miles, up and running after 40 years
'72 BMW 2002tii
'72 BMW Bavaria
'73 BMW 3.0CSi
'79 BMW Euro 635CSi
'99 BMW Z3M Coupe
'99 BMW Z3
'96 Winnebago Rialta

Five books available on Amazon (www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias%3Daps&field-keywords=rob+siegel)