Thread: Self Levelling Unit for RR Classic

Originally Posted by aRRon

Can anyone recommend where to source a self levelling unit for a 1989 RR Classic? Don't suppose there'd be anyone rebuilding them?

Pinched from a recent post by IsuzuRover. try WW shock absorbers. 33 Matheson Rd Virginia QLD for a rebuild. You may have to supply a rebuildable one on exchange.
Most people remove them and fit heavier coils or polyair springs inside softer coils. From a cross country articulation perspective i believe the load leveller has certain advantages over the afore mentioned solutions.
Wagoo.

Check this thread.

http://www.aulro.com/afvb/marketplac...-hydromat.html

Personally I'm not keen on them.

The reason is that when the levelling unit is pumped up it acts as a central pivot rather than the weight being supported over the outboard springs. We all know how unstable 3 wheeled vehicles can be, especially ones with long travel springs.

Get poly-air springs and up rate your coils to support the usual load in the vehicle.

Diana

The ebay seller I bought mine from only has/had 110 load levellers.
I haven't fitted it yet as i'm still working out which front springs to use, so can't offer an opinion of how well it all works either.

Originally Posted by Lotz-A-Landies

Personally I'm not keen on them.

The reason is that when the levelling unit is pumped up it acts as a central pivot rather than the weight being supported over the outboard springs. We all know how unstable 3 wheeled vehicles can be, especially ones with long travel springs.

Get poly-air springs and up rate your coils to support the usual load in the vehicle.

Diana

Personally, I can't agree with that!

The whole point of having the levelling unit is to maintain ride attitude within a wide load range whilst still being able to run low rate springs for articulation and ride comfort - which is why the RRC was such as quantum leap dynamically for 4x4's.

Having the self leveller above the axle centre allows the system to maintain a mean level ie body to axle clearence regardless of load; and of course removing the Boge doesn't remove the A frame linkage which acts as the lateral locator for the axle rather than a panhard rod or Watts link - It'll still pivot...

LandRover didn't fit the single but expensive Boge unit at the centre of the rear axle for nothing.Smaller units were available to be fitted on each side if just self levelling was their main goal. They fitted the big one centrally because from a cross country mobility perspective,a load leveller in combination with soft coil springs forms what is effectively a centrally pivoted and sprung axle assembly that maintains a more equal distribution of weight between the rear wheels over a much wider range of axle articulation.
Some of the more surprisingly offroad capable vehicles built had centrally sprung axles on at least one end. The old T and A model Fords of the 1920/30s are 2 examples. Although lacking 4wd, these cars and their hardworking truck derivatives were able to keep their drive wheels firmly planted over severe cross axle terrain that would bring a non difflocked leaf sprung Landy to an axle tramping halt.Almost every agricultural tractor built,either 2 or 4wd are other examples.The unsprung but centrally pivoted front axle on a 2wd tractor will 'walk' over cross axle undulations without unloading the rear drive wheels on either side. Now imagine that tractors front axle fitted with heavy springs on each side,or better still as a way of explanation, solidly bolted to the chassis so that it can't pivot. As one front wheel tries to rollover a hump or furrow, instead of just the front wheels assuming the lateral angle of the terrain, the whole tractor has to lean over, so the rear drive wheel on the same side as the hump becomes unloaded and if the tractor isn't fitted with a difflock it comes to a halt.
Anyone who thinks more heavily sprung Bogeless vehicles are as capable as the earlier Rangies are IMO deluding themselves.

When the Range Rover was designed the axle housing was made strong enough to cope with being centrally loaded.However when the 110 LandRovers were designed, the nongs that call themselves engineers basically just widened out the series 3 Salisbury axle and forgot about strengthening the axle tubes. I've seen a number of cracked and completely broken 110 axle housings off vehicles with and without Boge units.

Wagoo.

When I catch my breath I'll try to explain in basic terms what effect cross axle see saw action, with the springs as pivot points has on maintaining traction during extreme articulation.

Bill, would a Boge unit limit the amount of axle articulation? would it be able to handle shocks with 12 inch of shaft travel...I have been thinking for a while that the LL was a good idea....most think they are crap probably because they are so old and ned rebuilding

Originally Posted by uninformed

Bill, would a Boge unit limit the amount of axle articulation? would it be able to handle shocks with 12 inch of shaft travel...I have been thinking for a while that the LL was a good idea....most think they are crap probably because they are so old and ned rebuilding

Serg,ultimately they would do the same job as a centre limiting strap, which wouldn't necessarily limit articulation.If the static suspension height of the vehicle they are fitted to is greater than standard then an extension shaft would probably need to be fitted on the bottom end.
Because of the angle they are mounted at, it is difficult to calculate how much downforce they actually apply to the axle. I estimate around 1500lbs.
I replaced one with a double wound coil spring of around 380lbs inch and it wasn't near enough to compensate for removing the boge.
I've got an early Rangey up the hill with one still fitted, and what appears to be the original 124lb inch coils, but obviously the wrong dampers because it runs out of articulation without unloading the coils.my plate is a bit full for a few days,but when I get a chance I'll disconnect the dampers and cross axle the vehicle in a ditch to check the boges extension limits for you..
wagoo.