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Garage => Mechanicals => Topic started by: celberg on 27 August 2019, 01:12 PM

Title: Option 480
Post by: celberg on 27 August 2019, 01:12 PM
I have on my 1975 350SE option nr 480 self levelling suspension. Is this the same as on the 6.9? If not, what's the differrence?
Title: Re: Option 480
Post by: Randys01 on 28 August 2019, 02:20 AM
Huge difference. The self levelling suspension is a blow up bag on the rear axle to keep the car level using coil springs and conventional dampers. The 6.9 uses hi pressure fluid struts and nitro cells on all 4 corners: so it is the suspension.
Title: Re: Option 480
Post by: Max-NL on 28 August 2019, 05:30 AM
Actually the self leveling suspension also uses high pressure fluid struts in the rear with nitrogen cells and coil springs. Front suspension is normal (shocks and springs).

I think the main difference between the self leveling suspension and the 6.9 suspension is, that the 6.9 hydraulic struts is designed as shock and strut in one, whereas the self leveling suspension system is designed for self leveling only. The main suspension is done via the springs. And the struts are used for leveling and damping.
Title: Re: Option 480
Post by: daantjie on 28 August 2019, 09:14 AM
Here is a brain fart ;D

Perhaps seeing as all 6.9's came standard with the HPF suspension from the factory, this would not have been stated as an option code on the data card?  At least I do not see any code remotely referencing anything related to suspension on my car's data card.
Title: Re: Option 480
Post by: gavin116 on 28 August 2019, 12:58 PM
Hydro pneumatic suspension was available as an optional extra from the year 1976 on any of the model range 280S to 450SEL, provided you could of course afford it... Only type 450SEL 6.9 had this as standard equipment.
487HYDROPNEUMATIC SPRING SUSPENSION ALL AROUND
Title: Re: Option 480
Post by: Randys01 on 30 August 2019, 03:57 AM
Actually the self leveling suspension also uses high pressure fluid struts in the rear with nitrogen cells and coil springs. Front suspension is normal (shocks and springs).

I think the main difference between the self leveling suspension and the 6.9 suspension is, that the 6.9 hydraulic struts is designed as shock and strut in one, whereas the self leveling suspension system is designed for self leveling only. The main suspension is done via the springs. And the struts are used for leveling and damping.

A thousand pardons.  I was getting confused with another system.  ::)derrr!
Re above.."and strut"  perhaps this should be  "and spring". The sprung weight of the 6.9 is carried by the strut which is a defacto spring.
The SLS is a curious combo of technologies: it's rather clever...this situation sees the sprung weight of the car is carried by the coils.. not the strut.
As you say, the strut's role is primarily to adjust the ride height with minimal dampening function...the nitro cell performs a similar function.

A very complex system compared with the air ride shockers of the 70's  [maybe still around?] where you pumped up the shockers' internal air bag to maintain ride height.