By TCarr on Friday, December 14, 2001 - 03:38 pm: Edit

I am getting the feeling from various posts that:

a) unibody construction (as opposed to body on frame) is not good for offroad driving

b) 4 wheel independent suspension is also not good.

Why? Pros and cons? Anyone.

Thanks

TCarr
94 D1 88k mi, mostly to & from work, skiing and a little offroad.

By Leslie N. Bright (Leslie) on Friday, December 14, 2001 - 03:50 pm: Edit

a) It's not that a unibody is "bad"... it's got a good strength-to-weight ratio. But, a good frame is stronger (and heavier), and will have a longer life-span.

Cherokees, Grand Cherokees, Freelanders, they all have unibodies. They're competent off-road. But, they won't have as long of a lifespan doing expedition work the way a Disco could.

b) Independent suspension is fine on the road. When one wheel stuffs and the other drops on a live axle, you can get leverage applied across the axle. Although an independent suspension will try to keep all four wheels on the ground, but may not actually help with more traction.

Does that help?


-L

By Discosaurus (Discosaurus) on Friday, December 14, 2001 - 04:13 pm: Edit

Unibody construction also tends to be less rigid then a good body-on-frame design.

Take any unibody SUV, drive one wheel up on some high object (if you can ) and a lot of times you'll have problems opening the doors or the hatch because of body flex.

I heard rumors that some modified Explorers have actually broken windscreens because of body twist. Not good for a long life when used off road.

keith
discosaurus

By William Turner (Wturner) on Friday, December 14, 2001 - 04:31 pm: Edit

Discosaurus,

I totaly agree with what you said, but I do remember hearing stories of Disco windscreen breaking from body twist. Apperently the ones in the Discos were just set wrong in the first place.

TCarr,

Unless the Ind.sys. is special built (like Hummer)(not H2) you are also going to lack much needed wheel travel that keeps the tire on the ground n hairy situations.

There is a good link here somewhere that someone put when I asked the same question.

By William Turner (Wturner) on Friday, December 14, 2001 - 04:40 pm: Edit

Here it is...

http://www.prism.gatech.edu/~gte224i/IFS-SFA.html

By John Liebson on Saturday, December 15, 2001 - 09:09 am: Edit

I suggest that you look at the specifications for both the Freelander and the soon-to-be-released third iteration of the Range Rover, both of which use monocoque construction and independent suspension.

I rather expect that the next Discovery, which has been announced as being due in the middle of this decade, will use the same type of construction.

Things do change: I recall being asked if I wanted to buy an Austin Gypsy around the time I bought my first Land Rover, in 1960; the Austin was independently-suspended and was a failure.

I doubt that the independently-suspended newest Range Rover will be a failure, and, despite all the wailing about the Freelander, it has already proven itself to be quite a capable vehicle both on and off road.