Jimny Towing Trailer Off Road?

for the down hill bits breaking the trailer would help as the trailer pushes forward it applies the breaks not usually needed on a small trailer but in your case would sort that bit

I'm towing that sort of weight off-road most days. There aren't many hills in Norfolk but it certainly takes it toll on the poor Jimny in difficult, muddy conditions! I wouldn't want to take on any really steep off-road tracks. I have the same tyres and standard gearing but mine's the 16v engine. I'll be fitting a Liana 1.6 soon.

What exactly do you intend to be carrying in the trailer? 500kg seems a lot although I guess the Sankey is more than half of that? A lightweight trailer would be a better starting point, even if you have to beef it up a bit.

Ifor Williams P5
Something like this, although as Idiotmobil says a braked trailer would be a big bonus.

I have a P6e for my truck to lug about everything from rollers, garden waste, wood chipper, furniture etc - tows very well both on the motorway and beyond and i have 235's and no rocklobster. I just plan ahead and use the gears. Haven't had to knock it down below third even when on fairly step hills. Off road, it follows the truck very well, but i have noticed that if i break sharply it will try and push on the jimny, so i just drive with a lot of caution.

I do have crazy ideas about putting a solid lid beneath the tarp made from some marine ply and using a roof tent on top, but atm thats on the back burner.

I also have a P6E trailer, and can highly recommend it!

I think a sankey trailer weighs about 350 kg empty where the P6E is about 156-180 Kgs depending on specs