Thread: Self Levelling Unit for RR Classic

Originally Posted by wagoo

Within the constraints of what you can legally modify in QLD, there isn't much you can do with RAs to make them articulate more.Holey bushings give a bit more if you don't mind replacing them every so often.The only way you can have a F/R balanced system with RAs up front is to restrict the rear end. But then you might as well get a Commadore and a winch.
Wagoo.

To add to these comments.Both Mark and Serg have stated that they intend to retain the rear springs top and bottom. I'm not certain that would be a good idea with the Radius arm front end.In the ramp examination of both vehicles, the front suspension articulation was also at maximum. Had I engaged the rear difflock on the hybrid for example and continued to drive further up the ramp, the chassis would have tilted over significantly, and the right rear wheel with a retained spring would have begun to lift when the angular displacement of the axle was at about the 10 degree mark compared to the 14 degrees with unretained springs.
It is worth mentioning that this hybrid has form on this ramp and fell on its side once when the previous owner drove it up with the rear difflock engaged. The Chalk mark on the side of the ramp indicates the front wheel
only got to a vertical height of 85 cms before it overbalanced, wheras my own mongrel with 3 link front end,unretained closely spaced dislocating front and rear springs, will drive the front wheel to the top, a height of 150cm, keep all wheels planted and still remain very stable.


As an interesting aside.Although I recognise that ramp travel isn't necessarily an indication of a a vehicles off road ability, my humble 1989 Holden Jackaroo that has virtually no articulation, drove up the ramp to the 1 metre vertical height mark with the left front wheel about 95cm off the ground and the lateral chassis angle almost zero. So if there was an off road obstacle that replicated the ramp, the Jack would win that contest.
Wagoo.

Seems to me that the Land Rover engineers developed the most cross-country capable non diff-locked/ traction-controlled vehicle on the market with the original Range Rover, but they were almost frightening to drive on-road because of the unprecedented amount of body roll. In about 1976 I was driven along the Tullamarine Freeway in a Range Rover owned by a friend of my dad. Dad and I were clutching at things to hang onto as the driver hooked in on sweeping bends and the vehicle felt, to us, as though it were about to fall over.
I doubt there would be too many original early Rangies left with standard coils and dampers and a working Hydromat unit. My first Rangie, in stock configuration, was- subjectively speaking- the most capable off road vehicle I've owned and offered the smoothest ride.
On my last Rangie, I added a 40mm extension to the shaft of the Hydromat to try and recapture the load levelling effect with raised springs. Unfortunately this just led to the Hydromat bottoming out with a thud before the axle bump-stops were reached. If it weren't for the fact that my auxilliary tank fiillers are in the wheel arches, I would go back to stock suspension at standard height. I have toyed with the idea over the years of developing a height-adjustable replacement for the Hydromat, so i can do just that but still fill my tanks. Tried fitting an airbag in it's place a few years ago, but there is not room for one big enough to apply sufficient force.

I think LR have gone away from the Hydromat for chiefly market-driven reasons. The Discovery was built to a price, to compete with the jap vehicles and regain market share. This meant no hydromat, thus, presumably, stiffer coils to compensate. Also, I'm sure LR realise that those who buy new Range Rovers are generally not the ones who are into hard-core off-road use. In recent years they have used electronic gadgetry to obtain off-road capability, whilst maintaining a market-acceptable on-road ride. The ETC in the PUMA makes an incredibly capable off-roader, but I would hate to be paying for their maintenance in 10 years time.

Bill
Without getting into the perceived pros and cons of retained v's unretained springs.It would have been interesting to have disconnected the front shock on the hybrid when it had reached its limits and seen if it was restricting the amount of down travel,therefore fitting longer shocks would allow the wheel to possibly touch the ground again,and with the spring even though in compression it would still have the same force as if in compression,giving stability back to the vehicle and allowing it to be driven further up the ramp.Of course this is all hypothetical and depending on if the front shock was limiting down travel.
And as we all know,a ramp queen doesn't necessarily make a good off road vehicle and vise versa

Wayne

Originally Posted by wagoo

To add to these comments.Both Mark and Serg have stated that they intend to retain the rear springs top and bottom. I'm not certain that would be a good idea with the Radius arms front end.In the ramp examination of both vehicles, the front suspension articulation was also at maximum. Had I engaged the rear difflock on the hybrid for example and continued to drive further up the ramp, the chassis would have tilted over significantly, and the right rear wheel with a retained spring would have begun to lift when the angular displacement of the axle was at about the 10 degree mark compared to the 14 degrees with unretained springs.
It is worth mentionining that this hybrid has form on this ramp and fell on its side once when the previous owner drove it up with the rear difflock engaged. The Chalk mark on the side of the ramp indicates the front wheel
only got to a vertical height of 85 cms before it overbalanced, wheras my own mongrel with 3 link front end,unretained closely spaced dislocating front and rear springs, will drive the front wheel to the top, a height of 150cm, keep all wheels planted and still remain very stable.


As an interesting aside.Although I recognise that a ramp travel isn't necessarily an indication of a a vehicles off road ability, my humble 1989 Holden Jackaroo that has virtually no articulation, drove up the ramp to the 1 metre vertical height mark with the left front wheel about 95cm off the ground and the lateral chassis angle almost zero. So if there was an off road obstacle that replicated the ramp the Jack would win that contest.
Wagoo.
Wagoo.

Originally Posted by wagoo

To add to these comments.Both Mark and Serg have stated that they intend to retain the rear springs top and bottom. I'm not certain that would be a good idea with the Radius arm front end.In the ramp examination of both vehicles, the front suspension articulation was also at maximum. Had I engaged the rear difflock on the hybrid for example and continued to drive further up the ramp, the chassis would have tilted over significantly, and the right rear wheel with a retained spring would have begun to lift when the angular displacement of the axle was at about the 10 degree mark compared to the 14 degrees with unretained springs.
It is worth mentioning that this hybrid has form on this ramp and fell on its side once when the previous owner drove it up with the rear difflock engaged. The Chalk mark on the side of the ramp indicates the front wheel
only got to a vertical height of 85 cms before it overbalanced, wheras my own mongrel with 3 link front end,unretained closely spaced dislocating front and rear springs, will drive the front wheel to the top, a height of 150cm, keep all wheels planted and still remain very stable.


As an interesting aside.Although I recognise that ramp travel isn't necessarily an indication of a a vehicles off road ability, my humble 1989 Holden Jackaroo that has virtually no articulation, drove up the ramp to the 1 metre vertical height mark with the left front wheel about 95cm off the ground and the lateral chassis angle almost zero. So if there was an off road obstacle that replicated the ramp, the Jack would win that contest.
Wagoo.

Bill, could we trouble you for some more of your time? Would you be able to take the Range Rover back up the same ramp, but this time with retaining the coils. You could just use some zip ties, hose clamps or even some tie wire for this exercise. Im interested to see how much the springs will stretch, if the distance up the ramp is different and how tippy it feels. Regarding "feel" I have heard nurmous times how people have gone from unretained to retained and whilst they have given up some atricultion/travel they have all felt the vehicle more balanced and stable.....remembering all these are RA front and A frame rear....your special may be the exception that makes the rule.

Originally Posted by Dougal

In addition to the articulation and ride benefits. Handling deserves a mention too.

The central spring results in lower roll-stiffness on the back axle which helps it traction wise when cornering. If you remove the unit and increase rear spring rates they can become seriously tail-happy. The rear end will step out on you long before it usually would.

Landrover later in the RRC's life introduced sway-bars with a massive one on the front and a tiny one on the rear. This served the same purpose, giving greater roll-stiffness increase to the front end than the rear again to keep handling safe.

I would have thought the front have a higher roll stiffness due to it being radius arm. Is the difference coming when retaining medium rate coils up front and going to a heavier coil out back.....as a side note, the OEM springs on my 110 Def cabchassis, where a pergressive rate up front not to sure what rate but around the 200-220ib and the rears were atleast 350lb. It has never had a boge load leveler.

Dougal, can you describe the workings of these magical self energizing units?

Originally Posted by LowRanger

Bill
Without getting into the perceived pros and cons of retained v's unretained springs.It would have been interesting to have disconnected the front shock on the hybrid when it had reached its limits and seen if it was restricting the amount of down travel,therefore fitting longer shocks would allow the wheel to possibly touch the ground again,and with the spring even though in compression it would still have the same force as if in compression,giving stability back to the vehicle and allowing it to be driven further up the ramp.Of course this is all hypothetical and depending on if the front shock was limiting down travel.
And as we all know,a ramp queen doesn't necessarily make a good off road vehicle and vise versa

Wayne

Good point Wayne, and I went and did just that a few minutes ago.
I removed the top nut from the left front damper,left the right rear damper connected and tried again. The rear wheel lifted at exactly the same point as before.I thought you may have been on to something when the left front wheel pulled the vehicle up to the 80cm mark, but the gas damper on the left front was still correctly seated at the top and wasn't hooked on anything.The front ends articulation was limited by the axle bushings of the radius arms. The probable reason why the vehicle drove further up the ramp today is that the ground has dried significantly since yesterday.
Serg. I'll try and do as you suggest tommorrow. When I tried my bathroom scales under the right rear wheel,just at the point of spring dislocation, in the first test, the weight that wheel was still supporting was well in excess of the scales 120kg maximum, so there should be enough to stretch the spring significantly.
Wagoo.

how many different types of Load Levelers have there been on RR and Landrovers?
Have they all been made by Boge?

with regards to all this, what would happen if you raised the upper spring perches and got new springs of the same rate but longer made to suit....would there be any benefit? Keeping the same ride height, would the longer spring allow more droop, without coil binding under full stuff?