Rear air bag specs.

[Dougal]

Does anyone here have the measurements and any specs for the D3/D4/RRS rear air bags?

Looking for diameter, minimum and maximum length first.
Could they be used without the shock through the guts by making up a dummy shock or similar?

[Dougal]

Having dug up a few more pictures. Does anyone have measurements for the front too?

[Graeme]

The rears from bottom airspring mount (not shock mount) to top of the neck on the top plate is approx 250mm closed against the internal helpers/stops and 390mm open. The dia is approx 180mm.

The fronts approx 320mm open but only close by about 45mm before hitting the internal helper/bump-stop blocks. Approx 140mm dia.

[Dougal]

Thanks Graeme. I was just trawling (not trolling) through your LLams thread looking for any info.

[BobD]

The fronts approx 320mm open but only close by about 45mm before hitting the internal helper/bump-stop blocks. Approx 140mm dia.


Interesting. That rubber helper must be why you easily get a big thump from the front when you hit a pot hole at high speed on bumps that even a D1 has no trouble with. It is better on Llams +30 but still easy to get that suspension bottom out feeling on gravel roads.


Bob

[Dougal]

Thanks Graeme.

Is that close by hand or letting the whole vehicle compress them stationary? Would there be access to that internal bumper with the bag off the shock?

[Graeme]

Hand pressure only - I have 2 flogged-out sets in the shed, 1 with airsprings and 1 bare shocks. The bump rubber is about 30mm long (from memory) and fairly soft so probably compresses a lot. The shock piston will push in more than the full length of the rubber which just sits on the shaft between the top of the shock body and the top plate of the bag. I had considered carrying several spare rubbers to fit if an airspring failed on an outback trip - probably rather firm but better than nothing.

[Graeme]

Interesting. That rubber helper must be why you easily get a big thump from the front when you hit a pot hole at high speed on bumps that even a D1 has no trouble with. It is better on Llams +30 but still easy to get that suspension bottom out feeling on gravel roads.Even off-road height sometimes doesn't provide enough upward travel of the wheel to prevent the bashing but agree that +30mm can make quite a difference. The next Disco should have more travel, judging by the higher OR2 height and overall travel on the current RRV/RRS that uses the same platform but may still need some help from Llams at speeds above the OR2/OR1 thresholds.

[Dougal]

How much do you know about the L322 airbags Graeme?

I'm looking at airbag options for the classic rangerover. Ideally I'd like 8" of stroke. Stock ones are 6" stroke but I think landrover have also made significant gains in ride quality and air spring curves in the last 20 years.

[Vern]

Dougal, I spoke with air bag man about longer bellows, they gave me a part number for some and open and closed lengths, from memory was over 10" of travel. Will see if I can find where I wrote it down.

[TerryO]

Out of interest Dougal, why not consider just using the complete shock and airbag strut rather than dummying up a pretend shock?

[Dougal]

Out of interest Dougal, why not consider just using the complete shock and airbag strut rather than dummying up a pretend shock?

It'll be too long for the back. I suspect using the struts could be done in the front.
But that would be a change in suspension configuration which would require certification here.

[Dougal]

Dougal, I spoke with air bag man about longer bellows, they gave me a part number for some and open and closed lengths, from memory was over 10" of travel. Will see if I can find where I wrote it down.

Longer stroke is one thing. But wide availability and improvements in air spring ride are the other benefits I'm looking for.
The EAS RRC, even with buggered shocks, does ride a bit harder than say a RRS. Despite the RRC having 16" wheels with lots of sidewall and the RRS having 20" wheels with not much sidewall.

[~Rich~]

Don't forget that the suspension is also limited by the arms, axles, anti roll bar and the shocks as well as the air bags. Traction control almost negates the need to keep wheels on the ground.

[Dougal]

Don't forget that the suspension is also limited by the arms, axles, anti roll bar and the shocks as well as the air bags. Traction control almost negates the need to keep wheels on the ground.

If you're trying to crawl up something, certainly. If you're after ride comfort over uneven ground then you need travel.

Nothing is set in stone yet. I'm just investigating all the available options.

[Graeme]

How much do you know about the L322 airbags Graeme?Nil.

[Graeme]

The EAS RRC, even with buggered shocks, does ride a bit harder than say a RRS.
Does the RRS have CVDs that improve the ride? Also, my D4 transmits bumps more harshly now that the shocks have very little slow speed damping, ie worn-out shocks don't necessarily provide a softer ride.

[Dougal]

Does the RRS have CVDs that improve the ride? Also, my D4 transmits bumps more harshly now that the shocks have very little slow speed damping, ie worn-out shocks don't necessarily provide a softer ride.

I'm not sure about CVD. This particular RRS is 2011MY but Sept 2010 build date. I have the options list for it and can't find any reference to CVD or other suspension options.

I do a bit with mtb suspension so I've got a feel for what is caused by spring and what is caused by damper. These dampers are buggered and let the vehicle wallow. They've lost whatever low speed damping they originally had so certainly give a softer ride over small amplitude bumps. It's not as harsh as the early p38's, but if I can improve it I'd like to.

I don't want to throw new shocks at it until I'm sure of the direction I want to go with air springs. The aim right now is to see which other rover family air springs I can either write off as won't fit or keep looking into.