Ride height after changing front struts

[zombiemorg]

Hi all,

 

I've recently changed my front struts and springs but the ride height has jumped up by about an inch. The new parts have done around 250 miles and did settle slightly, but the front end is still pretty high. 

 

I replaced one of the struts today with a Sachs equivalent (due to a warranty issue around one of the fittings stripping with the Bilstein) and decided to fit the original OEM spring to confirm which was causing the issue. Even with the OEM spring, the ride height is still noticeably higher (and higher than the back end which also has new shocks/springs). 

 

Anyone experienced this with OEM-equivalent parts before? 

 

OEM struts: 1T0 413 031 HN

OEM springs: 1K0 411 105 AQ (Violet/Orange/Blue)

 

Sachs struts: 317 575 

Bilstein springs: 36-241583

 

OEM Strut/spring:

 

Sachs strut/OEM spring: 

[Carlston]

1 hour ago, zombiemorg said:

Hi all,

 

I've recently changed my front struts and springs but the ride height has jumped up by about an inch. The new parts have done around 250 miles and did settle slightly, but the front end is still pretty high. 

 

I replaced one of the struts today with a Sachs equivalent (due to a warranty issue around one of the fittings stripping with the Bilstein) and decided to fit the original OEM spring to confirm which was causing the issue. Even with the OEM spring, the ride height is still noticeably higher (and higher than the back end which also has new shocks/springs). 

 

Anyone experienced this with OEM-equivalent parts before? 

 

OEM struts: 1T0 413 031 HN

OEM springs: 1K0 411 105 AQ (Violet/Orange/Blue)

 

Sachs struts: 317 575 

Bilstein springs: 36-241583

 

 

Bilstein 36-241583 is sold to replace both 1K0411105AQ and 1K0411105HJ, so might match 1K0411105HJ rather than 1K0411105AQ.

 

The reason that I suggest that it might match 1K0411105HJ rather than 1K0411105AQ, is because 1K0411105HJ is a heavier duty spring, and usually an aftermarket brand won't sell a softer spring (or shorter spring) than the actual spring that it is being sold to replace.

 

This makes sense, because it could be dangerous to fit springs that are too weak for your car.

 

There are plenty of aftermarket springs that are sold to replace only 1K0411105AQ from brands such as Kilen, Lesjofors, KYB, Sachs, and many others. So there really was no need to compromise with a one size fits all Bilstein 36-241583 spring.

 

It would appear that the 1K0411105AQ should have a wire diameter of 11.75mm. If you measure the wire diameter of Bilstein 36-241583 you might find that it has a thicker wire diameter than this, perhaps 12.25mm.

 

You could also weigh the Bilstein 36-241583. It would appear that the 1K0411105AQ should weigh about 1.65kg, but the Bilstein might weigh about 1.85kg. Which again, would indicate that the Bilstein 36-241583 is not a 1K0411105AQ spring.

 

Bilstein 36-241583 front spring (sold to replace both 1K0411105AQ and 1K0411105HJ)

https://www.autodoc.co.uk/bilstein/7617653

 

Edited 4 September, 2023 by Carlston

[zombiemorg]

28 minutes ago, Carlston said:

 

Bilstein 36-241583 is sold to replace both 1K0411105AQ and 1K0411105HJ, so might match 1K0411105HJ rather than 1K0411105AQ.

 

The reason that I suggest that it might match 1K0411105HJ rather than 1K0411105AQ, is because 1K0411105HJ is a heavier duty spring, and usually an aftermarket brand won't sell a softer spring (or shorter spring) than the actual spring that it is being sold to replace.

 

This makes sense, because it could be dangerous to fit springs that are too weak for your car.

 

There are plenty of aftermarket springs that are sold to replace only 1K0411105AQ from brands such as Kilen, Lesjofors, KYB, Sachs, and many others. So there really was no need to compromise with a one size fits all Bilstein 36-241583 spring.

 

It would appear that the 1K0411105AQ should have a wire diameter of 11.75mm. If you measure the wire diameter of Bilstein 36-241583 you might find that it has a thicker wire diameter than this, perhaps 12.25mm.

 

You could also weigh the Bilstein 36-241583. It would appear that the 1K0411105AQ should weigh about 1.65kg, but the Bilstein might weigh about 1.85kg. Which again, would indicate that the Bilstein 36-241583 is not a 1K0411105AQ spring.

 

Bilstein 36-241583 front spring (sold to replace both 1K0411105AQ and 1K0411105HJ)

https://www.autodoc.co.uk/bilstein/7617653

 

 

That makes a lot of sense - I hadn't really considered the springs being uprated to cover the other part numbers. The second photo above is with the original OEM spring, but a brand new Sachs strut so while the ride height is still above normal, I suspect the strut might settle down in a day or two - in that case I will try and source some other springs. 

 

I did pick up these from Halfords which are sold as Sachs, but I believe Halfords/ECP are just stamping the Sachs name on another brands similar to what they do with Brembo. The Halfords springs do look specific to the standard suspension but I can't be sure - and they are significantly different in width/height (wider and shorter) compared to the OEM springs. 

 

Was hoping to avoid another 8+ day wait from Autodoc but guess that might be the only option.  

[Carlston]

22 minutes ago, zombiemorg said:

 

That makes a lot of sense - I hadn't really considered the springs being uprated to cover the other part numbers. The second photo above is with the original OEM spring, but a brand new Sachs strut so while the ride height is still above normal, I suspect the strut might settle down in a day or two - in that case I will try and source some other springs. 

 

I did pick up these from Halfords which are sold as Sachs, but I believe Halfords/ECP are just stamping the Sachs name on another brands similar to what they do with Brembo. The Halfords springs do look specific to the standard suspension but I can't be sure - and they are significantly different in width/height (wider and shorter) compared to the OEM springs. 

 

Was hoping to avoid another 8+ day wait from Autodoc but guess that might be the only option.  

 

One possible option, is KYB RH3553 which KYB sell to replace 1K0411105AQ. You can see on the autodoc listing that KYB claims that the length is 349mm and the wire diameter is 11.75mm.

 

Carpartsinmotion are listing them on ebay for just over £24 each including shipping.

 

If that doesn't work, perhaps look at the rear springs to see if they have started to sag and need replacing.

 

KYB RH3553 (sold to replace 1K0411105AQ)

https://www.autodoc.co.uk/kyb/825105

 

KYB RH3553 front springs listed on ebay

https://www.ebay.co.uk/itm/314665204298

 

Edited 4 September, 2023 by Carlston

[zombiemorg]

2 hours ago, Carlston said:

 

One possible option, is KYB RH3553 which KYB sell to replace 1K0411105AQ. You can see on the autodoc listing that KYB claims that the length is 349mm and the wire diameter is 11.75mm.

 

Carpartsinmotion are listing them on ebay for just over £24 each including shipping.

 

If that doesn't work, perhaps look at the rear springs to see if they have started to sag and need replacing.

 

KYB RH3553 (sold to replace 1K0411105AQ)

https://www.autodoc.co.uk/kyb/825105

 

KYB RH3553 front springs listed on ebay

https://www.ebay.co.uk/itm/314665204298

 

 

Good spot, I've ordered those. Rear springs and shocks are brand new so should be all good. Thanks for the advice!

[zombiemorg]

No change with the KYB springs unfortunately, they are actually a touch higher if anything 😔 the car is sitting at around 410mm from axle to the top of the arch which is about 10mm over the maximum range (391mm +/- 10mm) so something must be wrong somewhere.

 

Going for an alignment tomorrow (expecting the camber to be way out) so will see what the garage says and whether they can see anything obviously wrong.  

 

Running out of ideas as to what else it could be - but open to any suggestions. Will probably end up re-fitting the original springs and running those for a few weeks to see if things settle back down. 

 

 

[Carlston]

On 10/09/2023 at 16:17, zombiemorg said:

No change with the KYB springs unfortunately, they are actually a touch higher if anything 😔 the car is sitting at around 410mm from axle to the top of the arch which is about 10mm over the maximum range (391mm +/- 10mm) so something must be wrong somewhere.

 

Going for an alignment tomorrow (expecting the camber to be way out) so will see what the garage says and whether they can see anything obviously wrong.  

 

Running out of ideas as to what else it could be - but open to any suggestions. Will probably end up re-fitting the original springs and running those for a few weeks to see if things settle back down. 

 

Maybe the Sachs 317 575 front shock absorbers are causing the increase in the front ride height?

 

This of course shouldn't happen, because Sachs 317 575 is generally regarded as a quality brand. However, Sachs 317 575 is sold to replace a huge number of different OEM part numbers, so might not be a close match to 1T0413031HN. Although if it increased the ride height Sachs shouldn't be selling it to replace 1T0413031HN.

 

Did you check it really was Sachs 317 575?

 

With online sales, sellers get a lot of returns and so it's quite common for the wrong item to be put back in the box.

 

Maybe try Bilstein B4 22-183729 front shock absorbers instead of Sachs 317 575?

 

One point in favour of Bilstein B4 22-183729 over Sachs 317 575 is that this Bilstein model is sold to replace a lot less OEM part numbers than this Sachs model so it might be a closer match. But like I say, Sachs shouldn't be selling Sachs 317 575 if it raises the ride height...so it might not be this that is causing the increase in front ride height.

 

Bilstein B4 22-183729 front shock absorbers (sold to replace OEM part number 1T0413031HN)

https://www.autodoc.co.uk/bilstein/1043473

 

Edited 11 September, 2023 by Carlston

[Guest]

As the shock absorbers can be compressed by hand I would dismiss them as having any effect on ride height given the weight involved.

 

If the shock absorbers geometry is identical to that which they replaced, in that they offer the same spring preload when assembled, it can only be the springs supporting the car and that will give the ride height.

[J.R.]

If the dimension from the lower spring platform to the cut out for the steering knuckle clamp bolt is different then the ride height will be.

 

Its very easy to check.

 

Another poster corrected me long ago when I said that dampers damp and have no effect on the ride height, the gas filled ones do have a noticeable spring force when new as witnessed by the retaining wire for packaging and transport, I doubt whether that translates to any measurable ride height difference compared to the road springs against the vehicle mass but he was correct, this spring force is lost when the dampers age.

 

If the old and new struts have the same dimension mentioned above then it would have to be the gas precharge.

Edited 12 September, 2023 by J.R.

[zombiemorg]

12 hours ago, Carlston said:

Did you check it really was Sachs 317 575?

 

 

7 hours ago, MicMac said:

As the shock absorbers can be compressed by hand I would dismiss them as having any effect on ride height given the weight involved.

 

If the shock absorbers geometry is identical to that which they replaced, in that they offer the same spring preload when assembled, it can only be the springs supporting the car and that will give the ride height.

 

The struts are definitely correct (checked the label on the struts themselves) and the geometry does match up within a few mm.

 

 

3 hours ago, J.R. said:

If the old and new struts have the same dimension mentioned above then it would have to be the gas precharge.

 

Think this might be contributing to the problem. The new struts take considerable force to depress and I also changed control arms at the same time. Without a lift/ramps, I had to jack up the suspension corner-by-corner when torquing the control arms and think the force of the new springs/struts might be preventing the control arm from reaching their fully unladen position.

 

I managed to get a 10mm drop (now down to 400mm which is just within the 391 +/- 10mm spec) by disconnecting the control arm from the ball joint and torquing it in position without the strut/spring being a factor. 

 

Think I will leave the struts/springs to settle for a while and then re-torque the control arms once everything has settled properly. 

 

Appreciate all the advice!