New suspension installed - now have a bigger arch gap

[Smith2698]

Hi all, could do with a bit of advice. Last Sunday I installed new shocks, Springs and top mounts with bearings on my 2010 C30 2.0d. I was happy with the ride height but wanted New suspension at the front having previously done the drop links and wishbones. However after installing I was left with about a 1cm or so bigger arch gap and its been this way all week now having driven it for around 80 miles or so. Can I expect this to settle as I purchased the correct shocks/springs/top mounts for my model. Any help is appreciated

[Kawasicki]

It will settle, maybe not the whole way though.

[joropug]

Perhaps your old ones were saggier due to age and the newer ones are the proper ride height.

[I am alright Jack]

Kawasicki said:

It will settle, maybe not the whole way though.

This, and did you tighten things up with the weight on the wheels rather than with the car on a jack/stands etc.

[Carlososos]

Smith2698 said:

Hi all, could do with a bit of advice. Last Sunday I installed new shocks, Springs and top mounts with bearings on my 2010 C30 2.0d. I was happy with the ride height but wanted New suspension at the front having previously done the drop links and wishbones. However after installing I was left with about a 1cm or so bigger arch gap and its been this way all week now having driven it for around 80 miles or so. Can I expect this to settle as I purchased the correct shocks/springs/top mounts for my model. Any help is appreciated

If installed totally correct they will settle some but shouldn’t all. You will probably find over the same lifetime as the last parts it might reach similar.

[Smith2698]

Kawasicki said:

It will settle, maybe not the whole way though.

I'm hoping it does

[Smith2698]

I am alright Jack said:

Kawasicki said:

It will settle, maybe not the whole way though.

This, and did you tighten things up with the weight on the wheels rather than with the car on a jack/stands etc.

I tightened the strut tops with the car on the jack still, should it have been on the ground maybe?

[ChocolateFrog]

joropug said:

Perhaps your old ones were saggier due to age and the newer ones are the proper ride height.

Yes this almost certainly.

Steel springs will sag with age and use.

[Smith2698]

joropug said:

Perhaps your old ones were saggier due to age and the newer ones are the proper ride height.

That thought did cross my mind, I've had the car for 3 years and never done the front suspension on it and there's no recollection of it in the receipts and it's done nearly 80k now, that was part of the reason why I wanted to do them

[Smith2698]

ChocolateFrog said:

Yes this almost certainly.

Steel springs will sag with age and use.

I guess if they don't settle I'll just have to give it 40 to 50k 🤣

[paintman]

I am alright Jack said:

Kawasicki said:

It will settle, maybe not the whole way though.

This, and did you tighten things up with the weight on the wheels rather than with the car on a jack/stands etc.

^^^This.

Final tightening should be done with the car on its wheels & a few compressions (a few bounces on the suspension or drive a short distance) to allow bushes to take their correct normal positions.
If you tighten up with the suspension hanging down on a jack you may well find the car is higher than normal and the new bushes are overloaded.

[stevieturbo]

Smith2698 said:

I'm hoping it does

Genuine OEM springs/parts, or other brand replacements ? And definitely for your specific vehicle ?

Often the OEM can have particular springs, whereas generic replacements are just never a match.

But 1cm is pretty small, it should settle a little.

[Smith2698]

They were KYB equivalent springs that matched the part numbers of my old springs and the same goes for the Bilstein shocks and top mounts

[Smith2698]

paintman said:

^^^This.

Final tightening should be done with the car on its wheels & a few compressions (a few bounces on the suspension or drive a short distance) to allow bushes to take their correct normal positions.
If you tighten up with the suspension hanging down on a jack you may well find the car is higher than normal and the new bushes are overloaded.

Ah I see, I'm assuming the final tightening process applies if your using a socket set or an impact gun. Would it work if I was to jack the car up, loosen off the top mount bolts then lower the car back to the floor then tighten up or is it too late for that now considering I've done roughly 100 miles on them?

[Kawasicki]

Smith2698 said:

paintman said:

^^^This.

Final tightening should be done with the car on its wheels & a few compressions (a few bounces on the suspension or drive a short distance) to allow bushes to take their correct normal positions.
If you tighten up with the suspension hanging down on a jack you may well find the car is higher than normal and the new bushes are overloaded.

Ah I see, I'm assuming the final tightening process applies if your using a socket set or an impact gun. Would it work if I was to jack the car up, loosen off the top mount bolts then lower the car back to the floor then tighten up or is it too late for that now considering I've done roughly 100 miles on them?

Absolutely not too late. Suspension bushes are very tough. I haven’t read all the recent comments but normally suspension link bushes have more of an influence than top mount bushes.

[paintman]

^^^ What he said.