Snow Chains - D3/RRS

[101RRS]

I am considering putting my name down for an "offroad" trip in the Snowys a bit later in winter. Snow chains will be required on all wheels.

According to the handbook chains are to be be only fitted to the front wheels and must not be fitted to rear wheels but does not given a reason.

So, is the reason clearance around the rear wheels or a drive train issue.

While I would most likely select grass/gravel/snow for onroad use, I am open to suggestions for deep snow without an ice base - looking at the options Mud Ruts would seem to the best TR setting with Rock Crawl for the really slow stuff - open to suggestions from people with experience with deep snow in the D3.

Thanks

Garry

[Learner]

Hi Garry,
Unfortunately, many tour leaders (commercial or club) don't understand the capabilities of the D3/D4/RRS and just impose a blanket requirement.

I note that you say "... chains on all four wheels". If they say "chains for all for wheels" you should obviate this nonsense requirement by carrying chains for all wheels.

[101RRS]

Thanks for the comments - unfortunately they will have to go on. I would prefer to use my 101 but the RRS is a lot more comfortable in really cold climates. Chains will also be needed for it but chain rental places do not have large enough chains for fat 35" tyres. I am not prepared to spend almost $500 for a basic set of four for use once every few years.

Garry

[SBD4]

Garry, this is about all I could find on the subject from disco3 forum:

Here is what Skidrive say about the use of snow chains on 2 wheels.

This is a subject which can be tested and debated at ridiculous lengths!

In our opinion, using just 1 pair has two issues:

a) The un-chained set of wheels will spin easily. Electronic traction
control will detect this and distribute all of the power to the wheels
with chains on instead. This is fine, but means you're now driving a
full time 2 wheel drive vehicle, which completely defeats the object of
4x4! You're also left with a very heavy vehicle trying to move on snow
with only 2 driving wheels, which may make it less mobile than 2WD vehicle.

b) The wheels with the chains fitted will increase in diameter. If the 4
wheel drive is of a design which locks the front and rear wheels
together, each set of wheels will either lose a degree of traction, or
end up pushing the other set along. In adverse conditions, this could
conceivably cause transfer box damage, or accelerate tyre wear.

If you use 4 chains, you negate both effects, so we recommend this on
all 4 wheel drives where practical. I think you'll probably find Land
Rover's recommendation is based largely on the lack of clearance on the
vehicle. We can usually supply lower clearance or zero clearance chains
to get around this issue.

Seems to give a good case for chaining all 4 wheels.

Thread:

DISCO3.CO.UK - View topic - Snow chains

post is last on page 3

[101RRS]

Thanks for that - that is an interesting link - seems many D3 drivers are putting them on all four wheels and that clearance is not the issues.

Garry

[isuzurover]

Hi Garry,
Unfortunately, many tour leaders (commercial or club) don't understand the capabilities of the D3/D4/RRS and just impose a blanket requirement.

All the fancy electronics in the world can't compete with snow chains.

[CaverD3]

The was a lot of discussion about snow chains on the UK site. Problem was very small clearance to the suspension components on the front, the rears have only a small clearance between tyre and the wheel arch liner which has a the rear A/C pipes under it. If you have larger diameter tyres it could be a problem on extreme wheel travel. Some chains will fit others won't. All four wheels can be done

[ame=http://www.youtube.com/watch?v=Jfvrs3DTMC8]Discovery 3 on the Crosiere Blanche 2007 - YouTube[/ame]

Spacers are needed for heavier chains though (illegal here but never really understood why?)
DISCO4.COM - Log In

DISCO4.COM - View topic - Spikes Spider snow chains
DISCO4.COM - View topic - Snow chains
DISCO4.COM - View topic - Snowchains
DISCO4.COM - View topic - Snow chains

[101RRS]

Thanks - all the conflicting information does make it a hard call. What doesn't help is the lack of information about what happens in the car when each TR setting is selected. If the CDL is locked then chains on the front wheels on icey roads is understandable (4 wheel chains are better) but if the CDL is not locked (I understand the only setting where it is locked is Rock Crawl but you are limited to low range) the I guess that the programming when Gravel, Snow and Grass is selected takes that into account that there maybe chains on the front and varies the amount the CDL locks etc. However what do you select in deep snow offroad? there is no TR setting for that.

I have asked about this before, but it would be nice if there was a table that listed the cars actions when each TR response was selected - under headings such as Engine Power, Gearbox Response, TC Response, CDL Actions, and so forth. About the only actions I know of is that in Sand engine response and TC is enhance so that the car can launch itself out of the sand and in Rock Crawl the CDL is locked.

So if anyone has such a list please put it up.

Interestingly the TV Show "Most Dangerous Roads" this week was about testing some modified Jeeps (the support vehicle was a slightly lifted D1) in the desert area of Utah/Colorado just after a very heavy snow fall - pushing through 2-3foot of snow and they were not wearing chains and relied on their Muddies tread to keep them going. The D1 was in the lead until the going got too hard and they put a lifted jeep with 38" muddies and a 5.7L Chrysler V8 in the front to push through which it did albeit with a lot of difficulty. It highlighted the need to drive in the tracks of the vehicle in front and the difficulty wheeled vehicles have in driving in deep snow - still doable even if a lot of backing then charging the virgin snow was required.

Cheers

Garry

[chuck]

Garry

Have done a few snow trips in both D2 & D3.

Every time was without chains & on one trip we actually got to the top of Mt Skene in deep snow while passing a RRC equipped with chains that was stuck.

One theory is that the chains break thru the snow rather than airing down & riding on top.

Keep tyre pressure low much the same as soft sand.

The first trip in the D3 was frustrating as I used snow mode.

Snow mode is not the mode for deep snow - I found rock crawl best as in this mode the e diff comes in quicker if you have one fitted.

The first time was with 19" MT'R's and these were far less successful than later trip with 265 x 70 x 17 MTZ's.

In retrospect I found my D2 to be better in snow than D3 maybe this was because it was both higher & lighter.

Cheers

Chuck

[101RRS]

The first trip in the D3 was frustrating as I used snow mode.

Snow mode is not the mode for deep snow - I found rock crawl best as in this mode the e diff comes in quicker if you have one fitted.

\
Chuck - Thanks for the information.

I figured Grass/Snow/Gravel would be no good - I thought Mud Ruts may have better but without know what goes on in the car with each selection it is difficult to say.

Garry