Thread: Snow Chains - D3/RRS

Thanks for that - sort of explains why D3s/RRS can have issues in sand - the CDL is not locked.

Really looking at that Rock Crawl closest resembles the setup in a tradional 4wd. 5th gear in low range gives a top speed far faster than most more difficult offroad conditions would allow.

Likewise on snowy roads with chains on the front will stop the rear wheels spinning with the CDL locked in and in low range.

Cheers

Garry

Gary, from what I understand of the system, the CDL is a viscous coupling, so it has no electronic input or control, it relies on slipping to activate and lock the clutches using friction in the fluid, so I would think that the CDL would behave the same regardless of the TR setting selected, maybe a small change if a particular TR setting 'tightens' up the traction control and limits wheel spin?

The first question is which wheels do you have?
The 20's aren't suitable for normal chains due to the width. The spike-spider system is apparently $NZ800 for just the fronts.

As for capability. No-one I've spoken to has anything good to say about the factory fitted RRS conti sport contacts in the cold. Rubber doesn't stick to ice/snow and doesn't care how much electrickery you have.

The snow in the US/Canada and mainland europe is very different to the snow we get in NZ and I'm guessing Aus. Ours is wet and heavy, it quickly packs to hard and slippery (great for snowballs, until you get hit by one) where it glazes and under friction heats to provide a nice wet lubricating layer.
In the snow we get here on formed tracks a 2wd vehicle with chains will leave behind any 4wd vehicle without (unless that 4wd vehicle is a tractor). The chains both scoop snow and provide enough contact pressure to bite into ice.
I haven't found any tyres for the D3/D4/RRS which resemble anything like tractor tyres so chains remain the better option.

I found the skydrive claims pretty funny:
1. If you have chains on the front of a 4wd, then you can't spin the rears without also spinning the fronts.

2. The diameter increase losing traction?
Chains are only used when there is very little traction. There is always wheelslip involved and not enough traction or distance driven to cause tyre wear problems or transfer box breakage.

Four chains are always better. But there are very few situations where you need four. I have carried four many times but never needed to fit more than two.

Originally Posted by Summiitt

the CDL is a viscous coupling, so it has no electronic input or control, it relies on slipping to activate and lock the clutches using friction in the fluid, so I would think that the CDL would behave the same regardless of the TR setting selected

Quite the opposite - it uses an electronically controlled clutch that is programmed to allow different degrees of slip for the different TR settings.

Garry, isn't there an explanation of the various TR setting effects in your handbook?

Originally Posted by Graeme

Garry, isn't there an explanation of the various TR setting effects in your handbook?

Not specifically - only in general terms such as TR settings will adjust engine response, traction and other settings dependent on what TR mode is selected. The above link provided by Rich provides exactly the type of information that should be in the handbook.

Cheers

Garry

So the centre diff isn't torsen type in the d3/d4/rrs? It was a torsen in the big rr when they were released, I haven't heard if it was changed to another type.

Originally Posted by garrycol

Not specifically - only in general terms such as TR settings will adjust engine response, traction and other settings dependent on what TR mode is selected. The above link provided by Rich provides exactly the type of information that should be in the handbook.

Cheers

Garry

Note that the quoted section isn't _exactly_ accurate, for instance the diffs aren't "locked" immediately in GGS or RC - they're pre-primed to lock early, and the level of lock depends on whether you're talking about the centre or (if fitted) rear diff.

There are other small omissions/inaccuracies, but as an overview it's a handy reference.

Cheers,

Gordon

Originally Posted by gghaggis

Note that the quoted section isn't _exactly_ accurate, for instance the diffs aren't "locked" immediately in GGS or RC - they're pre-primed to lock early, and the level of lock depends on whether you're talking about the centre or (if fitted) rear diff.

There are other small omissions/inaccuracies, but as an overview it's a handy reference.

Cheers,

Gordon

Yes - thanks - I noted that. But it is providing the information I had been looking for.