Fool W124 Self Levelling??

[tjamesbo]

I use my 220TE to tow and launch a newly aquired boat only problem is when i launch it a lot of the rear ends up in the water (water level is approx 2 inches below the boot opening in order to float the boat off ). Clearly this is not good as during launch the spare wheel well and sills fill up with water .

I either need to change the car (dont want to yet ) or raise the rear and or lower the boat trailer (eg smaller trailer wheels ). re raising the rear option .......

Having checked my Towball it is low ie it sits at 33cm when spec says it should be 35-42 but i cant see a way of safely raising it . I then got thinking that when the rear self levelling system fails it tends to jack the rear of the car up ???? . Also having looked at it there is an adjustment nut on the lever between the valve and the anti roll bar the sixty four million dollar question is does anyone know if i can adjust and raise the rear ride height using this adjustment and by how much . Any suggestions / advice / info apreciated

 

[Cliveb]

You do'nt say the year of your estate. At some point the suspension was lowered, I don't know by how much though. Also if the tow bar was fitted after-market the rear springs will not be the right ones, yes Merc spec a stronger or longer spring when a tow bar is fitted from new. As for tricking the rear suspension into thinking it is lower than it actually is, I suppose it can be done, it would just open the valve earlier, I don't know what harm could be done but perhaps someone else knows better. The first thing I would do is fit the stronger/longer springs if your car has an after-market tow bar. Thing is, if you go that route the little adjusting screw on the valve would need adjusting to compensate for the higher ride height. Does anyone know the relationship between the valve arm and the anti-roll bar movement?

 

[tjamesbo]

The car is 1993 220te estate and despite towing a heavy caravan (1395kg) and having an outboard motor and zodiac boat in the boot plus 3 teenagers in the back! the car has always self levelled beautifully and taken all that lot down to south of france 4 years running now. So i'm not sure i need any stronger springs, surely the ride height should be set by the self level system . However by application of logic the correct level should also be at the height the spring is at with "design loading " in the car. Again using logic if i lower the adjuster then presumably the system will pump more fluid into the shocks to raise the height which would raise the spring level and if there ws no additional load in the back the spring would be trying to reduce the ride height, ie as long as i do not exceed the unsprung length of the spring ( both statically and in motion ) then it shouldn't break the system however i dont know how much adjustment there is or how much i can effectively raise it .

Any Expert opinions or engineers figured it out ????

 

[Cliveb]

Although I take your point about the springs on your car doing their job, my older, factory fitted tow-bar estate sat about an inch and a half higher than my later, non tow-bar estate. I was not just relying on memory; I had the two cars side by side as one was being a donor car for a diesel conversion and the difference was noticeable.That difference would be difficult to gain just using the self levelling adjuster. Of course your springs will be kept 'level' on your car when carrying a load, whatever the 'level' actually is, but you want it higher than 'level' to keep the water out. To try and trick the system you would lengthen the adjuster rod to the valve, this would cause the valve to open earlier, thus keeping the ride higher. Remember this valve is opening and closing a lot of the time anyway as the car goes over bumps. One way would be to experiment by turning the adjuster one thread at a time and see what happens.

 

[Bolide]

The rear springs just level the car when parked - the legs set the ride height and do the damping via the hydraulics & spheres. I believe that the static ride height is set by the spring length and that the self-levelling should be effectively off at this ride height. Sport suspension cars are said to have shorter springs to lower the rear

I doubt there is enough adjustment available to lift the rear of the car enough to keep it out of the water. But why not raise it up, using the height corrector, and see if there is sufficient travel?

Nick Froome
www.w124.co.uk

 

[FIBAMAN]

All of this seems to be getting a bit complicated. Why dont you buy a strop or use a short tow rope? Reverse the boat as usual to a point where you are lined up for launch, stop the car before it gets too deep in the water, brake your trailer, unhitch and attached adequate length of rope, take up slack, release trailer brake, then slowly let boat run down slip into the water, you may even not have to get your car wet.

 

[wireman]

If my memory is correct the max drawbar down load is 100Kg for the estate and 75Kg for the saloon. Exceeding this on the estate regularly will shorten the life of the self leveling.

 

[Bob.R]

If you adjust the self levelling to raise the ground clearance, when the vehicle is loaded more of the weight would be taken by the shock absorbers than the road springs. This would shorten the life of the self levelling system .....
'Correct' solution would be to replace the rear road springs and adjust the self levelling accordingly. Springs are not too expensive and relatively easy to replace.

 

[tjamesbo]

Thanks guys i like the suggestion of the towrope / strop and lowering it in ,sometimes you get too embroiled in the technical to see a simple solution.
I will also play with the adjuster as altho i can drop the boat in like this its harder to pull it out as it should be driven up the trailer to the bow board plates ( no winch on trailer at moment ), and seeing as its 1400kg of V8 inboard i think the boat would push the trailer along unless it was hitched but good advice and thanks for the inputs

 

[JEZ.S320L]

All of this seems to be getting a bit complicated. Why dont you buy a strop or use a short tow rope? Reverse the boat as usual to a point where you are lined up for launch, stop the car before it gets too deep in the water, brake your trailer, unhitch and attached adequate length of rope, take up slack, release trailer brake, then slowly let boat run down slip into the water, you may even not have to get your car wet.

Untie boat from trailer. Quick reverse, brake at the right point (important.!) and watch the boat slide off the trailer into the water. REMEMBER to have someone with a long slack rope (which is attached to the bow) holding on - otherwise the boat will slowly drift over the horizon.!

 

[Bolide]

If you adjust the self levelling to raise the ground clearance, when the vehicle is loaded more of the weight would be taken by the shock absorbers than the road springs

There are no shock absorbers on the rear of a W124 estate

This would shorten the life of the self levelling system .....

How?

'Correct' solution would be to replace the rear road springs and adjust the self levelling accordingly. Springs are not too expensive and relatively easy to replace.

The 'correct' solution would be to ensure the nose weight of the trailer was not excessive and to make sure the vehicle was being used within specifications

When owners of a BX estate find the rear end too low they reach for the height adjuster. They don't start reworking Citroen's design. Similarly, re-engineering a Mercedes to take account of overloading is probably not a good idea

Nick Froome
www.w124.co.uk

 

[FIBAMAN]

Untie boat from trailer. Quick reverse, brake at the right point (important.!) and watch the boat slide off the trailer into the water. REMEMBER to have someone with a long slack rope (which is attached to the bow) holding on - otherwise the boat will slowly drift over the horizon.!

To retrieve the boat using the same method in reverse, just be a bit careful or the boat may end up sitting next to you.