suggestion for lowering work

[1998K]

I've lowered my W202 with H&R and Koni externally adjustable dampers, This several mounths and abt 10000km ago.

So speaking with a nice Guy and lamenting due to really harsh ride compared to factory elegance set up, he kindly suggest me to slacken and re-tight all the nut and bolt with the vehicle lowered to the ground.

I've seen also this reccomendation on the Haynes Manual and I'm quite sure that the shop that installed the suspension didn't respect this (they tightened all with the hoisted car).

Questions are:
1) may this help really, considering the already done installation
2) how difficoult is this operation without a pit or other feature
3) new alignment is necessary? I belive no.

For the front suspension I'm quite sure it's only necessary operate on the top and botton bolt damper, since it should be possible to dismount and install spring and damper only with these nuts. Isn't it?

Thanks a lot:) :)

[benzfan]

The bolts that are important to tighten with the car on the ground are the main pivot bolts for the main suspension arms, front and rear. This would affect a car that sits unevenly following suspension work and to a lesser extent, the ride. However, these bolts would not have been touched during your spring/shock installation, so it should be unnecessary to do anything with them. The bolts at the tops of your dampers would be the only ones I would bother attempt to retighten with the car on the ground, and that should be easy to accomplish. This will probably not affect your perceived harsh ride compared to stock. It's just the nature of the dampers you have installed more than anything. They are a performance part, and the ride will suffer somewhat when installing them always.

[1998K]

Originally posted by benzfan
The bolts that are important to tighten with the car on the ground are the main pivot bolts for the main suspension arms, front and rear. This would affect a car that sits unevenly following suspension work and to a lesser extent, the ride. However, these bolts would not have been touched during your spring/shock installation, so it should be unnecessary to do anything with them. The bolts at the tops of your dampers would be the only ones I would bother attempt to retighten with the car on the ground, and that should be easy to accomplish. This will probably not affect your perceived harsh ride compared to stock. It's just the nature of the dampers you have installed more than anything. They are a performance part, and the ride will suffer somewhat when installing them always.

Dear benzfan, thanks a lot for your kind reply. So the suggestion is mainly related to the bolts at the top of the damper, this is easy. But as you said it's mainly a suggestion for a complete and well done work, it will be difficoult I'll perceive any difference.

But please: why not also the bottom bolt of the damper?

This for the front, and as far as the rear suspension, I've to check if the spring/shock install. invole the rear main arms! Do you know already?:)

I've appreciated a lot your help

Hi

[c280nz]

Have you set your dampers(shocks) to as soft as possible?

[1998K]

Originally posted by c280nz
Have you set your dampers(shocks) to as soft as possible?

Yes, they are at the softest level, thanks.:)

[martattack]

When you run performance shocks and springs, the trade-off for better handling is a harsher ride, and most of the time, not much can be done about it.

[Pagz]

Originally posted by benzfan
The bolts that are important to tighten with the car on the ground are the main pivot bolts for the main suspension arms, front and rear. This would affect a car that sits unevenly following suspension work and to a lesser extent, the ride. However, these bolts would not have been touched during your spring/shock installation, so it should be unnecessary to do anything with them. The bolts at the tops of your dampers would be the only ones I would bother attempt to retighten with the car on the ground, and that should be easy to accomplish. This will probably not affect your perceived harsh ride compared to stock. It's just the nature of the dampers you have installed more than anything. They are a performance part, and the ride will suffer somewhat when installing them always.

Im not sure if you ment you would only retighten the bolts ontop of the dampers,or retighten the main suspension arms....
so i'll pass my few cents also:)....

Basicly,when lowering your car,to preserve the life of any of the
fixed rubber bushes,they all must be released and retightened at the new ride hieght.
this as Benzfan said will also help ride quality,and in most cases keep the car hieght even...
doing this is best done on a lift or pit....i managed to do mine on the garage floor,but couldnt get the main front arm bolts up to torque spec until i had it in for alignment.

Rgrds,
Paul

[benzfan]

Right you are, Paul, and if anyone is still scratching their head over the need to do this, I'll fill in a detail that I should have mentioned before.

Rubber bushings are pressed into suspension components and don't move relative to that component after installation. Picture a large rubber donut held tightly on the outside. Now, place a hollow steel pin through the center, like all bushings have and don't allow it to turn in the hole through the center of the rubber. Now, bolt that inner pin solidly. It doesn't move relative to the frame member that the suspension component is bolted to. To get movement around the bolt axis, the rubber itself must twist back and forth. Nothing pivots on that bolt once it's torqued. So, if your car has its suspension at full extension when all those bushing bolts are torqued, the bushing rubber will be under considerable stress when the car is lowered and the suspension compresses. This is whey, after doing supension work on a hoist, it is a good idea not to torque those bolts until the car is on the ground, and if your car sits unevenly, try loosening and retorquing them on the ground to release some of the stresses in the bushings. This may or may not help in the case of the original poster. Probably not, but hey, it can't hurt.

The shock lower mount is similar, but it wont impair the function of the suspension like the main pivots will. The top shock mount requires a certain compression of the rubber and if you torque the nut on the top while the car is jacked up, you could reach the required torque sooner than you should. This effect all depends on whether or not the shock is of sufficient length for the suspension to just hang and allow you to do up the nut or not. Most aren't, so weight would likely have to be on the wheel just to get the top of the shock in the proper hole at the top where it mounts.

I wrote my original reply before work this morning so it was a bit rushed.

[Pagz]

Originally posted by benzfan
I wrote my original reply before work this morning so it was a bit rushed.

Thought there was alittle missing there;)

[1998K]

Dear Paul and Benzfan,

I really thank both of you for the important information you give me.

Paul, your clarification was really important because otherwise I was wondering to focus my attention only to bolts and nuts relevant to the dampers.

Thanks also for the detailed explanation of Benzfan.:)

So the conclusion is that when lowering a car (our Benz in particular), is better to release and retight (with car on the ground) all the front and rear rubber bushings (that are not directly involved in damper/spring installation); same also for damper bolts (i.e.: upper nut and bottom bolt/nut) to be tightened with car on ground).

So please final consideration is:
May this help also to me? Considering the lowering work has been done 12000Km ago?

To note that I don't lament any height/noise problem, this is only a suggestion a Guy gave me in order to reduce "rigidity" of the car!

:rolleyes:

I'd like to avoid possible problems (that I don't know) due to a modification to a car equilibrium already done.

Thanks again

Marco:)

[benzfan]

It certainly won't harm anything if you perform the work and might extend your bushing life, but it likely won't change the ride of your car. You now have a performance setup rather than a setup that compromised performance to give you comfort.

[1998K]

Originally posted by benzfan
It certainly won't harm anything if you perform the work and might extend your bushing life, but it likely won't change the ride of your car. You now have a performance setup rather than a setup that compromised performance to give you comfort.

Ok thanks a lot for your final consideration.

You help me a lot.

Sincerely

Marco:)