Thread: SLS and weight distribution hitches

Originally Posted by discolaw

Hello All
whats the latest thinking on SLS and using a weight distribution hitch to tow a caravan or trailer. Is a wdh unnecessary if you have SLS or is it incompatable with SLS and not recommended. I thought I saw somewhere that it wasn't recommended altho' I would have thought it would just make the job of the SLS easier. Anyone had first hand experience?
Cheers

According to the D2 manual owners, SLS is not compatible with a WDH, so that's the end of it from a legality/insurance/liability point of view.

SLS and WDH do different things. This has been covered many times, and on a lot of forums. It's a hugely contentious issue, but the undeniable mechanical fact is that they don't do the same thing.

Thanks Winaje
Interesting. My simplistic thinking was sls adjusts to the vehicles load and can't tell if thats from a few bags of cement in the back or a load on a towball. If a WDH gets some load off the towball, (or you take a few bags out) the sls just does its thing and adjusts. Obviously its more complicated than that but I don't want to set of a debate thats obviously been had before. Time for more research.
Be interesting to know the experience of anybody with sls who has ignored the manual
Cheers

Originally Posted by discolaw

Thanks Winaje
Interesting. My simplistic thinking was sls adjusts to the vehicles load and can't tell if thats from a few bags of cement in the back or a load on a towball. If a WDH gets some load off the towball, (or you take a few bags out) the sls just does its thing and adjusts. Obviously its more complicated than that but I don't want to set of a debate thats obviously been had before. Time for more research.
Be interesting to know the experience of anybody with sls who has ignored the manual
Cheers

OK, I'll crack open the can of worms again, and try to not let too many out...

The clue is in Weight DISTRIBUTION Hitch. A WDH transfers (distributes) some force along the vehicle chassis to the front axle. The Self LEVELING System does not, it only adjusts the height of the rear of the vehicle. So the most important function of a WDH, which is to increase downward force of the front tyres onto the road, is not carried out by SLS.

So, whilst they VISUALLY appear to do the same thing, they don't. This is easily proven, beyond doubt, by taking your vehicle and van to a weigh bridge. Run the front wheel ONLY onto the weighbridge with the WDH disconneccted, measure the indicated weight. Then connect and tension the WDH. Remeasure the indicated weight. It will have increased.

Yes it is a can of worms, which I will steer clear of.

However if you do use one then land rover recommend in the owners manual that you fit a different style of hitch as the standard one apparently won't cope with the stresses.

http://www.aulro.com/afvb/discovery-...ge-raa527.html

Cheers

Steve

Thanks Winjae and Rok Dr
I understand the WDH issue a lot better now and the debate about it. I'm looking at towing a van around 2 tonnes so not that big. If I steer clear of a WDH have sls owners found the std LR setup that comes with a D2 gives adequate and reliable stability for towing around that size, subject to the usual potential air bag leaks which would happen anyway.
Why is nothing ever straightforward with landrovers
Cheers

I'd research the upgraded Hayman Reese / LR hitch. If using it allows you to fit a WDH, then I'd do that. Makes a big difference to handling and braking.

Been using WDH (550lb kit) with SLS on our D2 since 1999. The towbar receiver was changed to the Hayman Reece unit by the dealer prior to delivery (it was a option offered as soon as towing was mentioned), and yes it is more substantial. When I was there in about 2001 for a service, they had a pile of factory receivers going for scrap.

Towing 2.7t, the D2 with SLS and no WDH, it is more stable than the D1 was with WDH. Add WDH to the SLS D2 and it improves out of sight. As mentioned they are two very different systems that can complement. However, it was stressed to me by HR that the bigger kits need to be set up properly. SLS can mask how much tension you have in the bars (this is why they want you to change the receiver), make sure you measure how far you push the front down - only have to do that once & mark the chain.

To open the can further, I use WDH on the L322 as well, and again, it improves it out of sight.

Anyone got thoughts on this http://towbarsaustralia.com.au/base/....aspx?pid=6783

cheers