Volvo C70 2.5T Coupè 1998 Suspension Comfort Problem

[reise]

Hello.

During the 2018 i start to change a lot of spare parts for suspension and steering for my C70.
The goal is to erase the steering noise and bad comfort of suspension.
I list the new spare parts i buy and installed from mechanician:

BUYED AND INSTALLED

- x2 Front Spring Seat 30683637 (Polar Parts)
- x2 Front Support Plate 31200599 (Polar Parts)
- x2 Front Helper Spring 9140067 (Polar Parts)
- x2 Front Protecting Bellows 9140068 (Polar Parts)
- x2 Front Shock Absorber 9173850 (Sachs)
- x2 Rear Shock Absorber 9173851 (Sachs)
- x2 Rear Support Plate 9461524 (Sachs)
- x2 Front Washer 30647969 (Polar Parts)
- x2 Rear Helper Spring 3516327 (Polar Parts)
- x2 Front Stabilizer Link Bar 31212730 (ComLine)
- Tie rod end Front axle left 271598 (Kager)
- Tie rod end Front axle right 271599 (Kager)
- Control arm front left 8628499 (Optimal)
- Control arm front right 8628500 (Optimal)

A total of 24 spare parts.
Plus, i was send to a steering box repair center, my steering box (was have problem of oil leak and noise during parking steering)

The situation: the suspension comofort was bad and now is bad.
The mechanic told me that he found more spare parts to replace:

TO BUY AND TO WILL INSTALL

- 2x Rear Link 3516122
- 2x Steering Road 9191410
- 4x Bushing 3507923
- Engine Pad 9434435
- x2 Stabilizer mount (Skandix, not provided by Volvo)

In your opinion, installing these last parts, will the suspension comfort return as new? Or will it always remain very rough on road bumps?
If the problem not will solve with this last spare parts to buy i'll buy the new front and rear springs, but is very hard to find.
The code of my suspension (the string code on right bottom of VIN plate) is 46 (front spring) and B (rear spring).
For info: wheels is 7"x16" Volvo Ursa on 205/55 R16 Dunlop Sport MAXX RT (for now, but in future i buy 7.5"x17" VolvoCanisto on 225/45 R17 (that were those with which my C70 had left the factory)).

[SteveSarre]

Hi Reise,

That's a long list of parts.

I notice that you have the rear
Engine Pad 9434435
There is also a similar front pad at the front.

Can you provide a link to the Skandix site for the two
x2 Stabilizer mount (Skandix, not provided by Volvo)

But can you describe what the problem is?
Is it when you go over a small bump? A big bump? Turn a corner? Brake? etc
Is it a knock or a vibration?
Do you feel it through the steering wheel, or through the seat, or can you only hear it?

On your 205/55 R16 Dunlop Sport tyres what is the air pressure?

Steve

[reise]

During brake or corner is ok the car.
Good brake and good handling.
No squat and no dive. Ever flat in acceleration or brake.
The problem is for all bump or hole or anything defekt of street. The car is similiar than a model car without suspension.

[jack taylor]

Hi, Just a thought but the ride may be better with higher profile tyres such as 60 or 65. jack

[SteveSarre]

Hi Reise.

Is the car sitting at the correct height (the wheel arches should be a couple of centimeters above each tyre)? If one of them is much lower then maybe you have a broken spring.

When you go over a bump, is there a knock or a vibration? Is it heavy knock or a light knock?
Do you feel something through the steering wheel, or through the seat, or can you only hear it?
Which part of the car does it come from?

On your 205/55 R16 Dunlop Sport tyres what is the air pressure?

Have you looked at any of the parts that your mechanic has taken off the car? Could you see for yourself that they needed replacing?

What do the current trailing arm bushes 3516122 bushes look like? Can you see them and are they in bad condition?

Steve

[reise]

The suspensions doesn't work properly and the car seems like a die cast model without shock absorbers, so I can feel any road irregularities. Zero vibrations but I want to know if this bad behaviour is due to old suspensions or other kind of issue.

[don kalmar union]

You have not mentioned the springs and your complaints about the car's reaction to bad road surfaces and potholes sounds to me like a problem with aftermarket, shorter and higher poundage road springs.

Have you checked the ride height all round with Volvo's standard measurements?

Also a picture of the car, side on, might give us a clue...

Don.

[reise]

Originally Posted by SteveSarre

On your 205/55 R16 Dunlop Sport tyres what is the air pressure?

Steve

Volvo label on side of door say: 2.2bar front and rear (for light load).
I try 2.2, 2.5, 3.0bar, but not change comfort. Suspension not have travel and not have stop.

Now as my previous message i have Sachs Made in Germany shock absorbers with some code of original Volvo Sahs 1998, and Kyb springs mark as equivalent code of original Volvo.
Handling? Perfect (but too with old shock and springs)
Comfort? Poor (as old shock and springs)

Solution:

1

If i'll buy Shock absorbers and springs of C70 Cabriolet Comfort Chassis?

My C70 is Coupe with Dynamic Chassis (Coupe not exist with Comfort Chassis)

2

If i'll buy Koni Special Active Shock Absorbers and leave actual KYB springs?

Goal: dramatically improve comfort.

[tony209]

That is the chassis set up I have on my T5 cabriolet, koni special active shocks and KYB springs, it works really well although the front is still a bit too firm with the KYB springs. KYB front springs are 442mm compared to 460mm stock(dynamic) and rears are 400mm compared to 430 stock. I removed the KYB rear springs because they are too low and make the front very light - so light I had to lower the pressure in the tyres. With the KYB springs on the front and standard height springs on the rear, the front is too low and probably the reason why the ryde is too firm. When the weather improves, I'm going to put the correct height dynamic springs back on the front and see what the ride is like.

I can highly recommend the koni active shocks, it's just a mater of getting the right springs. I have had a chat with a KYB engineer, he was a bit surprised (and concerned) to hear that the KYB rear springs effect the ride height of the front! I think the KYB rears would have been better if they were 410 - 420mm

A big problem with the C70 is the front is too heavy and therefor requires a stiff spring. I have a P2 V70 and the ride is superb, it's a very similar set up to the P80 but it's a lot lighter at the front, aluminium bonnet and battery moved to the rear. Also, it looks like Volvo tilted the engine slightly to the rear shifting some weight off the front axle.

What size wheel do you have? These cars were designed to have 16" rims, a larged wheel diameter and lower profile tyres will give a firmer ride.

[reise]

The space between the tire and the wheel arch is currently quite large. I don't think the KYB have lowered the set-up, quite the contrary! However, I will purchase the Koni Special Active. At the time of replacement together with the mechanic we will measure the total height of the original Volvo Dynamic Chassis and KYB springs. How can I assess if the original springs (which I have removed and kept) were still good or worn out? The original Volvo springs had about 220.00km.