Thread: .......Defender, JK Jeep, FJ40?? Offroad Quality's?

Originally Posted by 4x4 MORE

Hi guys just wondering why does a Defender, JK Jeep, a FJ40 have a wider track than the body?

And what else makes them good off road compared to say a Hilux or Jeep Patroit or Landrover Free lander??

What do you think makes a real 4wd?..

I can't speak for Jeep or Toyota. but the Defender body is the same dimensions as the Series vehicles with mods for coils springs etc. I suppose it saved a hell of a tooling up cost, waaay cheaper to bung on wider flares.

The jeep isn't good offroad,neither is the FJ40,if I was doing the simpson,canning etc I'd take the Freelander over most traditional 4wd's.Most of the older generation of 4wd's have the wheels wider because when they first came out they were fitted with 7.50x16 sized tyres because thats what was available,now they are fitted with 265 size so flares are a cheap way to allow it. Pat

Originally Posted by 4x4 MORE

Hi guys just wondering why does a Defender, JK Jeep, a FJ40 have a wider track than the body?

And what else makes them good off road compared to say a Hilux or Jeep Patroit or Landrover Free lander??

What do you think makes a real 4wd?..

The Defender has permanent FWD, coil springs and better articulation compared to the first two alternatives and, as opposed to a Freelander, a low range box.

Originally Posted by 4x4 MORE

Hi guys just wondering why does a Defender, JK Jeep, a FJ40 have a wider track than the body?

And what else makes them good off road compared to say a Hilux or Jeep Patroit or Landrover Free lander??

What do you think makes a real 4wd?..

The Defender has flares because the conversion from leaf spring to coil suspension included change to the track of the Rangerover (for parts commonality), without changing the body dimensions.

The Jeep increased the track to increase the stability for highway use after major increases in power over the years. Body width was kept the same, possibly for the same reason as the Defender.

The FJ40 appearance is purely styling, intended to make them look a bit like the other two.

What makes a vehicle good offroad is mainly a matter of ground clearance, approach and departure angles, gearing (including low range), suspension travel and ruggedness.

But a lot of other factors come in as well, including driving position, durability, weight distribution, centre of gravity, hose out interior, raised axle breathers, good engine dust protection, clutch that will stand abuse, no vulnerable bits underneath, and probably many other factors.

The most common points that rule out four wheel drives as "real" (whatever that means!) four wheel drives are gearing, ground clearance and ruggedness.

John

Originally Posted by JDNSW

The Defender has flares because the conversion from leaf spring to coil suspension included change to the track of the Rangerover (for parts commonality), without changing the body dimensions.

The Jeep increased the track to increase the stability for highway use after major increases in power over the years. Body width was kept the same, possibly for the same reason as the Defender.

The FJ40 appearance is purely styling, intended to make them look a bit like the other two.

What makes a vehicle good offroad is mainly a matter of ground clearance, approach and departure angles, gearing (including low range), suspension travel and ruggedness.

But a lot of other factors come in as well, including driving position, durability, weight distribution, centre of gravity, hose out interior, raised axle breathers, good engine dust protection, clutch that will stand abuse, no vulnerable bits underneath, and probably many other factors.

The most common points that rule out four wheel drives as "real" (whatever that means!) four wheel drives are gearing, ground clearance and ruggedness.

John

Thanks very much mate, can you pls explain the points I have highlighted?

Originally Posted by 4x4 MORE

Thanks very much mate, can you pls explain the points I have highlighted?

Driving position:-

A "real" four wheel drive needs a driving position that will give good road visibility even when coming over a steep crest and into sharp turns, and allow rapid turning of the steering when, for example, following a winding track or having select a path through obstacles. It also needs to position the driver so that he/she can operate all the controls almost as easily even if there is a steep lean to either side or a steep up or down grade.

Usually this means an upright seating position.

No vulnerable bits underneath:-

I thought that was self explanatory! This means that when you scrape high centres on tracks, the bit that rubs is not going to get damaged. In vehicles with solid axles rather than independent suspension, this is usually the differential housing, and these are usually tough enough to stand it. Steering components, if in front of the axle, need to be well above the axle, and if behind must be above the axle.

As an example of the sort of problem that can happen, especially with independent suspension, my Citroen, with adjustable ground clearance up to 15", and heavy weight bias onto the driving wheels is pretty good off road. But (as I found), if it does hit a high centre, what hits is a thin alloy panel below the inboard front brake disc, with the disc taking the impact. This easily breaks the gearbox extension housing, and fixing that is not cheap.

Also, the design needs to have all easily damaged parts underneath protected from flying stones and stick thrown up by the wheels. Typical bits that can suffer damage are handbrake mechanism, brake pipes, exhaust system, fuel lines, wiring - anything that is easily damaged.

Another suspect problem is catalytic converters, which can rapidly become a serious fire hazard if driven over long dry grass - it is all too easy to have a design that allows dry grass to collect around it and cause a fire, even if you are careful not to park in long grass.

John