I think the tongue weight of a Disco is only 500lbs, meaning it will support only 500lbs on the trailer hitch.
Tongue weight is how much the "tongue" of the trailer weighs, the tongue of the trailer is the part that connects to the trailer hitch.
To much weight on the trailer hitch and your front wheels will have less weight on them which means they have less grip on the road, which means less power pulling out of the water because only the rear wheels will have grip.
Less stopping power because the front wheels have less grip, less turning ability because the tires have less grip, also pulling to much weight when you turn a corner in the road your tow vehicle will want to go straight because the weight of the trailer will want to push it straight.
8000lbs I'd say give it a try, 10,000lbs no way in hell, not unless it was the end of the world and I had to pull my kids to safety on a 10,000lbs trailer.

Add the fact that you live were it is 130*F in the shade, your truck is going to overheat before you get the boat out of the water, the DII cooling system is to small.

 

Do you have SKYPE, we could talk on that or I can send you my number here in Colorado.
As for the air pressure, disregard what was posted and keep all your tires at 40 pounds to prevent wear to the drive line under load.

 

Will certainly need brake controller for any vehicle. For that size boat an F150 won't be a good choice either. You add tongue weight to the GVW (which changes with what is in the truck) of the truck and contents, and don't exceed the GVWR (which is fixed by the factory) of the vehicle.

 

Yes, please disregard everything that land rover wrote about your vehicle. They obviously don't know as much about the vehicles they built as someone on the internet.

Instead, make up your own mind:

Maximum front axle load:
2646 lb (1200 kg)
Maximum rear axle load:
- 5-seat vehicles with coil spring suspension 3792 lb (1720 kg)
- 7-seat vehicles with coil spring suspension 3968 lb (1800 kg)
- Vehicles with self-levelling suspension 3968 lb (1800 kg)

 

Think about it - we see plenty of action photos of Discos rampaging through mud, climbing rocks, etc. Don't see a lot of them hauling low boy trailers with bull dozers up the same mountains. It is not a question of pedigree and precision, it just takes a larger vehicle to control a heavy boat safely. A modest ski boat, a couple of jet skis, or an aluminum pontoon boat - no problem. The junior version of the Titanic is another story.

 

Guys, thanks for your replies.

All a bit confusing with some saying it's a no-no whilst other saying it's possible.

Incidentally, whilst driving to work today, I saw a Jeep Cherokee Laredo 4.7L (looked like a 2003 model) pulling a twin axle trailer with a 28ft motor boat. I followed it for a good 3 miles and it didn't seem to have any issues pulling, braking and going over the 'up ramp-flat-down ramp' type speed bumps. This guy was going 60kph without any trailer swaying which really makes me think my D2 can do the job.

Now, I have no experience in towing but know basic physics about inertia and momentum and I believe (granted with no expert knowledge) that, driven sensibly with caution, the D2 will do the job for short runs upto 20-30kms, driving no more the 40kph.

I also think my D2 will need some upgrades if the engine and drive train is going to last.

With regard to cooling, I agree with Spike, with my location, there will be some cooling issues. I was thinking of replacing the radiator with a specially made deeper core one which should improve cooling and and using a couple of bottles of water wetter to bring down the temp.
I asked the previous owner about towing the boat with my D2, as he has experience and this is what he said :

'Engine power isn't the issue. Stopping is more critical. As long as no big hills or long distances you should be fine The trailer has surge brakes and with the long wheelbase is pulls very nicely. You'll see in the picture that I have the trailer adjusted back to balance the tongue weight. It's happier behind a pickup in Connecticut as we have lots of hills'

I've attached some pics which should give an idea of the trailer tongue ( I could not attached them previously for some weird reason)

Mike - I'm not set up for Skype but i'd appreciate it if you could send me your number and I can call you. If I do the mods/upgrades on the D2, I have a Landy garage here in Dubai with boys from the UK that are half knowledable with the RR/Defender/Disco .

Work done recently -blocked the EGR, new engine mounts, complete oil flush with synthetic oil, new coolant, tensioner pulley, new HT leads, new plugs, I have 30mm hubcentric spacers all round, gearbox oil change, suspension airbags changed to springs, 4 new tyres (255/55/18)

Thanks to all who are contributing to this excellent forum

 

here is my 2 cents. You will not have fun……. I tow a small - 18 foot - boat with my 97 D1 with the 4L V8. The boat and trailer loaded with things weigh maybe 2500 lbs. I have no problem pulling the boat up very steep ramps on lakes in the mountains of Washington (Lake Chelan, Banks Lake, etc). I have had a hell of a time going over mountain passes in the Pacific Northwest on an Interstate freeway (Snoqualmie Pass on I-90). The engine cooling is not adequate. The power is not there. Going down the mountain is even harder as the trailer is pushing your car down. You can extrapolate from that. I think you do need additional Radiator and oil cooling capacity.

I agree this is a great bunch here…..

 

Also read this on Weight Distributing Hitches…..

HowStuffWorks "How Towing Weight Distribution Systems Work"

 

Thanks Gigs for the link . . very helpful

As I said, I would not think about pulling 9500lbs in a 03 D2 through long distances or long winding mountainous roads. My use is a lot simpler (simpler he says . . lol)- straight runs to and from the slip with no continuous incline. Max distance 30kms - Max speed 40kph.

 

Mike - any luck in sending me your number?

Thanks