Thread: Towing with Disco 4

Originally Posted by Ian McK

Hi All you LRovers out there
We have a Disco 4 and it tows (3.5t) off-road van very poorly. Scary in fact. (Just a new (second hand). The previous owners say it was a dream to tow. I have been through weight distribution, wheel alignment and next on the list is tyre pressures. I see these things on the www. LED trailer module LAND ROVER DISCOVERY 4 / LR4 (L319) LED TOWING ADAPTOR MODULE


1. we don’t have an issue with led lights but I am not sure the disco “recognises” the trailer.
How can I tell?
2. we donÂ’t seem to have an issue with the trailer brakes but now have some doubt with possible wireing connections. What is the consequence of incorrect wireing connection?
3. Does anyone recommend a towing adaptor module?
4. The van has dexter sway control. It can be felt working but will not correct the big movements caused by overtaking trucks etc. Should a Dexter eliminate ALL sway?

thanks in advance
ian

Out of curiosity, what is the D4 doing that’s scary? At what speeds? What van is it?

You can cheaply and easily fit a pair of ballast resistors so the car recognises the trailer. I wrote up fitting some to my D5, but the principal is the same:

Wiring up a pair of ballast resistors for towing a trailer with LED lights (aulro.com)

You can wire them up on the caravan, but by doing it on the car, they will work with any trailer with LED lights. Much cheaper than the modules - I think my setup cost around $40 for the resistors and the switch.

Good luck sorting it out.

Cheers
Numb Thumbs

Hi guys. I have a 2008 RRS TDV8 towing 3.5 tonne 25 foot van. I suppose I can talk to this thread as I believe the RRS has the same chassis as D4. If I'm wrong, shoot me down.
I towed our vans (25 foot Jayco Heritage and 25 foot Jayco Sterling) without issue UNTIL I changed tyres on the RRS. I was using Cooper Zeon LTZ's until they lost the will to live and I wasn't able to get more so I fitted Cooper Discoverer H/T's and the dynamic changed immediately. It was like chalk and cheese. Perhaps check what tyres you are running. I was thinking because the Zeons were a semi off road tyre that they were stronger in the sidewalls than the Discoverers and didn't squelch around as much but apart from that I don't know. I was running 20" rims. I have a set of 22" rims with Pirelli tyres so I put them on and they have improved the stability. I'd prefer not to run 22's with their lower profile on some of the shmitty roads we have in Australia but they are better than the Discoverers.
Just my thoughts.

Originally Posted by V8Ian

Don't put too much credence in that potty-mouthed, self proclaimed expert.

Hi again

Been v busy in the last few days.
Anyone who thinks retirement is restful needs to think again.


I have had the van weighed. Unfortunately it was not to our touring weight but I will attempt to describe.

Front Lhs 703kg Rhs 683kg
Rear. Lhs 671kg. Rhs 632kg
Tow ball. 196kg

The water tanks were 1/2 full.
they are above the axles so you could add 25kg
to each wheel. The van was missing food.
The fridge and pantry are above the rear axle (one each side)
I suppose you could add 20kgs each side to the rear axle

Plus clothes

this would be about
Front. Lhs. 730. Rhs. 710
rear. Lhs. 720. Rhs. 710
Tow ball 210 (clothes)
ATM 3080

The only things not on the floor are plates cutlery and hanging clothes

The spare tyre is mounted very high on the rear Lhs.
I think I can have it relocated to the front draw bar.
(reducing the centre of gravity, reducing weight on rear Lhs wheel
and increasing the tow ball weight.

Before I commit to a full time change. I will shift the tyre and strap it to the front gas bottle frame for a test drive

Is this a feasible test?

I am running 42psi all routine the van.
Is that too much? Should I run more/less in the rear

Thanks for everyoneÂ’s suggestions so far

Ian McK

"It sounds like something is wrong with the balance of the van".

I agree!

I tow a 2.5 T boat/trailer 10,000+ km each year. My 2015 TDV6 tows it effortlessly at the speed limit where safe (ie up to 130 kph). All this stuff about the Disco recognising the trailer is news to me - I don't think my Disco knows that its towing a boat. My electric brakes are set up so that they come on just before the Disco brakes - the result is that I think the Disco/boat combo stops at least as well or even better than the Disco alone.

I don't tow a van, and 3500 kg would pull it up a bit, but I would think it should still be stable if the van is set up properly.

OK, given the post above - I am running Pirelli Scorpian AT Plus tyres on 19" wheels: placarded pressures on the Disco and 35 psi on the boat trailer.

I don't think I have seen anyone ask if the caravan is level.

I had terrible problems with my D4 when towing my Evernew 900i (3.5t fully loaded) using the hitch as supplied by LR. Having already been through all the other weight distribution protocols, my problem was that the van was not parallel to the ground. It was low at the front putting all the load on the front wheels of the Van with rear wheels unable to take their share of the load. As soon I changed the hitch to an adjustable hitch my problem was solved with the van now level.

I am grateful to this forum that put me in the right direction.
Details of my query and the responses from the more educated than me can be found under the following topic.

D4 sway when towing heavy caravans

Sorry I don't know how to attach a link in this application.

Cheers
Chris

I forgot to mention; I put Dexter on our van.

It is something you hope you never need - my understanding is that it is supposed to kick-in when you are building up serious sway.

Sadly, contrary to advice, my Dexter kicks-in every k or so on dirt roads applying the van brakes when not needed. I have to remove the fuse to stop it working when we travel on the dirt.

More sadly SWMBO has said we are not travelling on dirt roads again (after GRR and Cape York) so my dexter won't be a problem.

Cheers
Chris

Originally Posted by Ian McK

The spare tyre is mounted very high on the rear Lhs.
I think I can have it relocated to the front draw bar.
(reducing the centre of gravity, reducing weight on rear Lhs wheel
and increasing the tow ball weight.

Before I commit to a full time change. I will shift the tyre and strap it to the front gas bottle frame for a test drive

Is this a feasible test?

I am running 42psi all routine the van.
Is that too much? Should I run more/less in the rear

Thanks for everyoneÂ’s suggestions so far

Ian McK

Using the 4psi rule, I started at 45, but have to pump my 265 75 R16 ATs to 50 then they operate at 54 or thereabouts. I've checked my Safety Dave TPMS and the values are just about spot on. I'm usually about 3.3T but licenced for 3.5.

For the record, I work on about 6% of gross van weight (210 kg for 3,500) for my towball weight, and carry one of those tube scales to check every now and again - we have a few items that can be relocated to balance the load. Works for my little D4.