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Discussion Starter #1
I have just finished installing the new Protechs tonight. The rear was a breeze, the front was a major pain in the *ss.

While I was changing the rear shocks, I was on the lookout for the source of a very high pitch squeaking noise. It sounded like metal on metal, but I didn't see anything wrong with the bushings.

Well, when I changed the rear shocks, I found the problem. These were the original rear shocks (14 yrs old with 27K miles), and honestly they were in great shape in terms of corrosion, leaking, and dampening.

But they had both moved off the centering hole, and in another 20K miles, it could have been ugly if I had left them be.

The driver's side was wearing outward and the passenger side was wearing inward. The driver's side shock stem was about 1/2 worn through, and the passenger about 1/3 through.

If you have this squeak, you might want to check this before it's too late.
 

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There's something odd with what's happening. What's causing the upper shock mountings to shift to the left (both sides) with sufficient force to wear the shock stem. I would check the tracking alignment, I think. I can't figure out what would create that must side load on the upper shock mount.
 

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I wonder if your suspension bushings were tightened while the wheels were off the ground? The top of the shock was probably too loose as well, the bushing doesn't look distorted, and the washer isn't cupped as it should be to help center the bushing.
 

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Discussion Starter #4 (Edited)
I plan to get an alignment after I am sure the ride height is the way I like it, so I will report back.

Current tires have been on for almost 10 years and are worn about half way. The wear is very even and no cupping. So I don't think the alignment could be that far off.

I don't think the stock washers and bushing were set up to center the shock absorber. The Protechs have no inner washer and have bushings shaped to center the shock. I made sure to tighten them well.

Which bushings on the suspension need to be torqued when the car is on the ground?


1998 Lotus Esprit V8
 

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This is fairly common. Not tightened up when the shock is loaded and the bushings are overtightened. Easy fix, you weld a large washer over the hole.
David Teitelbaum
 

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To answer your question, all suspension bushings should be torqued with the wheels on the ground "at the specified ride height"...
 

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Discussion Starter #7
To answer your question, all suspension bushings should be torqued with the wheels on the ground "at the specified ride height"...
Don't doubt it, but I am curious why? Most of these bushings let the suspension pivot freely, so what bad is happening when you tighten the bolts with the car lifted up?


1998 Lotus Esprit V8
 

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Haven't seen a V8 factory setup, but looks same as the 4. The upper hole for the shock is oversized and there is a special washer which fits over the bushing and keeps the stud centered in the hole. Then everything is torqued so that there is no sideways movement of the stud possible.

Your original setup looks incorrect. I would be a little concerned about the Protech bushing surviving long term without the proper washer. Especially now that you have a couple of ragged holes.

Randy
 

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Discussion Starter #9
This is fairly common. Not tightened up when the shock is loaded and the bushings are overtightened. Easy fix, you weld a large washer over the hole.
David Teitelbaum
Sounds like this should be one of those "routine checks" for the Esprit then.




1998 Lotus Esprit V8
 

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Wingless Wonder
1988 Esprit Turbo
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Sounds like this should be one of those "routine checks" for the Esprit then.


Most of these bushings let the suspension pivot freely, so what bad is happening when you tighten the bolts with the car lifted up?
Re-torquing suspension bolts was specified as part of a B service by Lotus. That should happen mid-way between the routine oil change and the major C service (timing belt, coolant, brake fluid replacement).




Rubber bushings do NOT let the suspension "pivot freely" when properly tightened. Rather, they need to be "set" so as to be centered ("relaxed") at the midpoint of their designed range of twist.


So, after doing any suspension work, you leave the suspension bolts just-snug (not loose), drive it a few hundred feet, then tighten the bolts with simulated weight of driver and passenger. I've used water softener salt bags to add about 100 lbs to the seats when I do it on my parking lift (the kind with ramps).

(Although, as my age and weight increases, I REALLY need to consider adding more weight to my base setup...) -poke- rotfl
 

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Discussion Starter #12
Rubber bushings do NOT let the suspension "pivot freely" when properly tightened. Rather, they need to be "set" so as to be centered ("relaxed") at the midpoint of their designed range of twist.

Thanks for that explanation.

But there aren't too many bushings in the suspension that are just rubber. The top of the shocks is the only one I can remember. Most of them have a metal sleeve encased in rubber that then has a bolt through it, including the bottom of the shocks. Those with sleeves pivot freely, so does what you are describing apply to those bolts as well? And if so, I am curious to the physics of why?
 

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Typically you tighten rubber suspension parts when the car is "neutral" so you do not have any preload or "wind-up" on the rubber parts. That means you have the car on it's wheels so is there is weight on the suspension and the car is at ride height. If you are anal you will also have a 1/2 tank of gas and some weight in the driver's seat (and maybe some "junk in the trunk"). This applies to the control arm bushings, trailing arm bolts, and shock mounts. The ball joints, tie rod ends, and sway bar mounts should not be affected.
David Teitelbaum
 

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The large rubber bushings with the sleeve inside (8 in rear, 2 in front) do not pivot freely when torqued, they rely on compliance of the rubber in a twisting motion to control the movement of the A-arms in the front and upper/lower links in the rear.
 

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Wingless Wonder
1988 Esprit Turbo
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weight in the driver's seat (and maybe some "junk in the trunk")
I'm trying to lose a few pounds, I swear! :sheep:



As Jim said, the rubber bushes with the metal "distance tube" are designed to be bolted solidly to the tube. The tube is not supposed to slip relative to the through-bolt.

It's good practice to coat the through-bolts with grease so that they don't corrode solidly, making subsequent removal impossible....:panic: ...but they are NOT supposed to slip. Only the rubber is designed to twist.


:up:
 
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