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Andrew van den Heever
Member Since: 09 Jun 2007
Location: Cape Town
Posts: 340
  
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St Pierre White is always going on about how much he likes a live axle. Apart from the ability of independant front suspension to bottom out, that the FFA doesn't have, what is the great advantage? The D3 has massive articulation, to the point that a guy in a Toyota got out of his vehicle and walked accross to me to comment on it. Surely this has even more advantages??
Any 4x4 techno gurus out there prepared to shed some light? 
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 23rd Jul 2008 8:26 am |
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Jonty
Member Since: 13 Oct 2007
Location: On the beach
Posts: 417
  
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With the Disco3, we don't even need to worry about bottoming out because of how the suspension works. The advantage of live axles is that they make it easier to lift the suspension and to fit aftermarket diff-locks. You also don't need to worry about cv-joints.
The disadvatages are reduced clearance below the diff-pumpkin (and indeed the axle itself) and poor ride-quality. The difference in ride quality between a 100 (IFS) and 105 series landcruiser is quite marked. The high speed on-road handling is also crap in most cases.
I think it's usually a case of old is best and 'that's how it was always done' with many 4x4 fanatics who refuse to move with the times.
Saying that, not all independent suspension systems are equal. AFAIK, it's only the Landrover system that, combined with air-suspension, still gives great wheel-articulation and cross-linking to prevent bottoming out. The M-class, Touareg etc have very poor wheel travel when in 'off-road' height and are also easily bottomed out (even the Hummer! though that is expected with coil springs).
The new 200 series Landcruiser has a similar set-up (but hydraulic) to LR to prevent bottoming out at the front (rear is still live axle).
Hope this helps!
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| 23rd Jul 2008 9:13 am |
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Andrew van den Heever
Member Since: 09 Jun 2007
Location: Cape Town
Posts: 340
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Thanks Jonty! That really does help.
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| 23rd Jul 2008 9:51 am |
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heine
Member Since: 07 Feb 2007
Location: Midrand
Posts: 4054
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AFAIK the air suspension emulates a live axle when you are in low range and some of the TR modes 
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| 23rd Jul 2008 10:31 am |
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AndrewW
Member Since: 06 Aug 2007
Location: Saddleworth
Posts: 2302
 
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| Andrew S.... P..... W..... .....? |
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Took me a bit to figure out the simple title...
Thought it was a round-up of the Andrews on the forum 
Anyway - since my brain was kickstarted, it's going to have it's pennyworth (Old English word!).
My father was an aeronautical design engineer (Lancaster airframes &c) and had a huge technical design interest in wheels, suspension, shockloading etc as well as a petrolhead's desire to make 4 wheels stick to flat-ish horizontal-ish surfaces. He was not an off-roader.
His dictum was that the prime suspension function of keeping maximally equalised weight on all wheels was a function of sprung weight (chassis, body etc) over unsprung weight (wheels.tyres, brake assembly). Live axles added to unsprung weight and were therefore a BAD THING.
BUT early independent suspension (at least for a driven axle) demanded inboard pivoting of the half-axle and the tendency of the track dimension to alter during suspension movement, especially the lateral load-shift encountered in cornering. The shift initiated the then dreaded and sudden "side-slip" (these days more happily entered into as a controllable "oversteer") and landed the 1950s UK/US motorist in the hedge / nearest oil-field. Hence the VW beetle was "unsafe at any speed" (Ralph Nader). The outer wheel on the bend/curve eventually tucked under the car and it rolled. (Been there, done that  ).
Enter McPherson strut for the front end, maintaining the wheel attitude, but still with track variation. Then multiple link configurations which maintained the track dimension and even reversed the wheel attitude problem.  .
Improved materials allowed for 2WD or 4WD from a body mounted diff. to the "floating" wheel hub and independent suspension was no longer a bar to driving the wheels.
BUT
Simple independent suspension does not give equalised loading to all wheels on an uneven surface, and off road grip was better with a couple of heavy live axles than 4 independent wheels. Lightly loaded wheels spun and dissipated the driving force requiring locked or limited slip differentials.
UNTIL
...logic controlled air suspension with long-travel multiple link configurations and traction control (to the point where differential locks are less important )
Once you have that you can reduce the relative unsprung weight and you have the ideal on-road situation as well as the best off-road.
Ladies and Gents, I give you.......
The D3 
AndrewW 2006 D3 finally swapped for a 2016 D4 Graphite in Graphite grey. No mods
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| 23rd Jul 2008 11:19 am |
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heine
Member Since: 07 Feb 2007
Location: Midrand
Posts: 4054
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Uhmm - so we're OK then 
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| 23rd Jul 2008 11:33 am |
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AndrewW
Member Since: 06 Aug 2007
Location: Saddleworth
Posts: 2302
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I was going to publish that under the title of "A Short (?) History of the Development of Automotive Suspension"
2006 D3 finally swapped for a 2016 D4 Graphite in Graphite grey. No mods
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| 23rd Jul 2008 11:48 am |
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heine
Member Since: 07 Feb 2007
Location: Midrand
Posts: 4054
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Wish I could remember it all next time I need to shoot down a critic of air suspension 
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| 23rd Jul 2008 11:55 am |
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Andrew van den Heever
Member Since: 09 Jun 2007
Location: Cape Town
Posts: 340
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Hey Andrew.
Thanks for the really detailed reply.
I think Jonty is right in that many times I have heard a 4x4 expert say that a live front axle is better and more reliable in true off-road conditions, and they are probably stuck in the past. There is an impression that IFS is for "soft-roaders", and I guess that without air-suspension and terrain response that may be the general rule.
It would be really good to see just how well the Terrain Response system does when directly compared to the more hard-core 4x4's. We tend to get classified somehow not as capable as a Defender or a Cruiser, which I think is unfair.
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| 23rd Jul 2008 1:14 pm |
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Doc
Member Since: 17 Jan 2008
Location: New Hampshire
Posts: 352
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Thanks AndrewW for the explanation and comments  I too, like Heine, hope I remember half of the content during the next lively 4x4 suspension argument
DOC D3 2005 HSE V8 model, snorkel, nudge bar, uprated tow hitch (12T), Goodyear Wrangler MTR (MT) tyres, National Luna battery box, Outback roof-rack, Takla seat covers.
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| 23rd Jul 2008 7:09 pm |
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AndrewW
Member Since: 06 Aug 2007
Location: Saddleworth
Posts: 2302
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Aw! Thanks guys!
 2006 D3 finally swapped for a 2016 D4 Graphite in Graphite grey. No mods
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| 23rd Jul 2008 7:38 pm |
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Baben
Member Since: 15 Feb 2006
Location: Kyalami
Posts: 2059
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Whether the D3 is as capable offroad as a Defender or anything else is a moot point for me (but IMO is certainly as good as anything else I have experienced if youtake my driving capabilities out of the equation  , PLUS it is the most versatile vehicle I have ever owned, and I have had Prado's, Isuzu's etc.)
There is no vehicle that will suit MY requirements as well as the D3, some of which are:
1) Take the kids to school (in complete comfort and safety, whilst they watch movies) in the traffic
2) Take the dogs to the farm (3 big Labs) (in complete comfort and safety)
3) Collect mirrors for the renovation. and deliver them intact
4) Take the family to Durban on the highway (in complete comfort and safety) at an average speed of 130km/h
5) Take the family to Camp Syncro (in complete comfort and safety, unshaken, and without kidney belts or thoracic damage)
6) Collect an oversize 2m, 140kg friend from the airport, and dliver him (in complete comfort and safety) to his hotel
7) Take a client out to lunch (in complete comfort and safety) in style
I could go on, but I think my point has been made.
If someone wants to drive a car with a live axle, let them. If someone wants to listen to AM radio, let them. I certainly won't join them, but then again that's my choice, innit? I have come to appreciate my independant air suspension and iPod
You can never overcome the fact that people have their own opinions, and when that person has a big podium like a TV slot, whats the point of arguing.
We know the truth about the D3 and its awesome capabilities. More people like Alice and Deon are letting their Defenders leak quietly in the back yard because they now have D3's. More neighboure of mine are getting rid of their X3/5's and buying D3's.
Land Rover's reputation is intact, and the D3 has a lot to do with this.
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| 24th Jul 2008 4:05 am |
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Doc
Member Since: 17 Jan 2008
Location: New Hampshire
Posts: 352
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Well said Baben
I too got rid of my 2.8i Defender to move across to a D3, but it sounds from what you said that I have used mine far more roughly than you have - Bowhunting trips, expeditions, gates events, etc. I was also a "dyed in the wool"  Defender fan and have owned V8 110's since about 1990. The D3 has changed my mind D3 2005 HSE V8 model, snorkel, nudge bar, uprated tow hitch (12T), Goodyear Wrangler MTR (MT) tyres, National Luna battery box, Outback roof-rack, Takla seat covers.
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| 24th Jul 2008 5:29 am |
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Andrew van den Heever
Member Since: 09 Jun 2007
Location: Cape Town
Posts: 340
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Baben, you have said it all.
I have never had such a versatile vehicle that is equally at home in the rocks and mud as it is in the office car park. I have filled the car with a forest worth of stuff from the nursery, have moved the contents of an entire house, have taken the family on holiday with surfboards and bikes etc, etc, and all as you say in complete comfort and safety. When I am offroad I can do things I thought were impossible. Amazing.
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| 24th Jul 2008 8:54 am |
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Deondef
Member Since: 08 May 2007
Location: Randburg
Posts: 790
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Baben wrote: More people like Alice and Deon are letting their Defenders leak quietly in the back yard because they now have D3's. More neighboure of mine are getting rid of their X3/5's and buying D3's.
Land Rover's reputation is intact, and the D3 has a lot to do with this.
Ok Ok - gee but you guys can wallow 
If we can get this right with fellow D3's I will get rid of the Defender :
THE LANDROVER DEFENDER WAVE
Being a Jeep owner has entrenched me amongst the ranks of the cool trendy and aloof Sports Utility Vehicle (SUV) crew. Or so I thought.
It was only when I borrowed a friend's Landrover Defender that another world of camaraderie, spanbou and humanity was introduced into my driving experience.
It is amazing how disarming it is when you get your first wave from a Landrover Defender owner and you spend 30 minutes trying to work out where you know them from. When you get another wave a few minutes later you really start to think you've been set-up. Is there a sticker on my car….am I part of a breakfast show radio campaign and then it hits you! It's not you or your Jeep. It is the Defender they are waving at .Or what it represents.
Don't get me wrong not Range Rovers or Freelanders but the old school looking original Landrover – The Defender with a heritage dating back to 1954 -that all look the same to Jeep drivers. The relatively dependable, military looking bundu basher that you know will leave an oil mark on your driveway.
By the third wave I was waving back enthusiastically, even trying to get the first wave in.
These are not dismissive waves either – waves with intent, fellowship, neighbourliness and genetically Defender…generations of post 2nd World War owners integrity symbolized in an honourable wave.
It is only when you have to return the Landrover that you are reminded of the social commentary the wave is making. You actually miss being part of the inner circle. They can't see your Landrover type attributes while they are so well disguised within the confines of the ice cool Jeep SUV team. (It is no wonder the new Jeep add is doing well as it adds a human element into the normally sterile, androidal vehicle market.)
It reminds me of times spent in rural or small communities and of times gone by. It is certainly something that reeks of nostalgia and if only it could be bottled.
With my Jeep starting to mark its territory on my driveway it could be a great opportunity to make a leap of faith to the other team - Team Landrover .. I know which Team I'll be flagging down if I break down.
The one waving with a smile. Erstwhile - D3 S '07. Dual battery system. Upgraded tow hitch. Mantec skid plate. Frontrunner rr. Tmax double headed built in compressor
Defender TD5 110 CSW '00. "With everything"
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| 24th Jul 2008 9:07 am |
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