Thread: Defender 8x8

Originally Posted by uninformed

I cant see how having the rear axle steering on this thing would be any good....plus how much stress would be on it. Have any of you towed a dual axle trailer????

I own a tandem trailer.

Three axles aligned like that it would want to go in a straight line whatever you did with the front wheels, particularly in mud, snow and sand.

For fourth axle steering, you would have the rear axle following not steering, it could be programmed with sensors detecting the amount of pressure on the drag ling which would then apply a little turn on the rear axles using a hydraulic ram or linear actuator connected to the drag link. (or a mechanical linkage with ratios in the order of what Dave suggests)

Would something like this be more suitable?

Looks like the rear is steered with some kind of hydraulics.

That is a very interesting drive system!

I've seen that somewhere before.............

I think Ive even seen (pictures of )the vehicle that spawned from it....

Esarco 8X8.</B>


The Esarco eight wheel drive (8WD) was developed in the early 1980's by Major Michael Somerton-Rayner.

The first Esarco was based on standard Land Rover 110, (later called Defender) engine, transmission and axles. The front and rear axles steer - in opposite direction - which made for a tight turning circle, a concept seen on the AEC road train as far back as the 1930's.

Two full-time four wheel drive Land Rover transfer cases were used, mounted back to back with the first driving the second through their power take-offs by a dog-clutch and a short drive shaft. The first transfer case drove axles one and three and the second transfer case drove axles two and four. The axle differentials being offset, the prop-shafts could pass neatly over the intervening axles on their way to the appropriate differentials. All in all there were six differentials - four in the axles and two in the transfer cases.
Early Esarcos used the Land Rover 3.5L V8 engine. On the road, the second transfer case was disconnected and the vehicle became an 8x4. Offroad, the second tranfer case was connected to the first, making an 8x8. The Land Rover transfer cases contained a "centre diff'" for full-time four wheel drive and were equipped with diff' locks.
Land Rover coil-spring suspension was also adopted frpm the Land Rover 110. A ladder-frame chassis and a simple forward-control cab structure completed the picture.


At some stage the concept was taken up by Stewart and Stevenson of the USA, becoming the Esarco SS 300. Part-time 4WD transfer cases were adopted and pictures show free wheel hubs fitted to axles 1 and 4. Engine options became a 7.3L V8 diesel engine or a 6-cyl petrol engine. Although intended as a "utility" 8x8, at least one Esarco was prepared for racing! In 1991 Jacob Westerfeld and Michael Amiralay prepared this Esarco (left) for the Paris to Capetown Rally, also aiming for the Paris Dakar Rally.
Today 1997 --> this eight wheel drive is produced as the SS300.
Back in the UK, the Esarco concept was bought by the MWG Group which refined the design but was put into administration. The 8x8 was purchased by the ex MD of MWG, Mike Hearn and a new company, H.U.G.O. All Terrain Vehicles Ltd. which built final prototypes and type approved the 8x8. Mike H 5/1998 -->

Some further information.

Esarco 6x6 and 8x8 FCs

And here is a thread on Pirate with driveline photos etc.

http://www.pirate4x4.com/forum/showthread.php't=355327

Different truck (6x6) , but nice bit of engineering
( dogleg in the A frame ?? )

That dogleg in the A frame is the only thing i don't like about the folley set up in the pictures above, i've always been told not to weld a forged member,mind you if they filled it in with plate it would probably be fine, or gusseted it properly but that job above would be enough to make me not buy one. It just kills the whole concept of triangulation