building a 4wd boat trailer

[ellis_d]

hey guys im pretty keen on building a 4wd boat trailer for my 385 explorer as my old trailer is shagged.has any one got any hints or tips in making one to share.
or maby you have some photos that you could post. any info would be greatly appreaciated;D

[propdinger]

hey mate
the first problem with that is loading and unloading the boat at ramps makes it very hard to get the boat on and off and you will need a 3 speed winch otherwise it will be like trying to pull very heavy weight. mate had a boat that was raised and it was the worse trailer so just remember to try and keep the height down on your frame. oh and the bum used to drag on the sand when it was beach launched

[hellfish]

g,day ellis. Exactly how far are you planing to go with this trailer? To make an off road boat trailer that is really capable of going just about anywhere and not sef destruct or destroy your boat is not as easy as most people will tell you.

[Flex]

I have helped built 2 offroad trailers before. Both for heading up FNQ.

heres a link to the latest one I built.
http://www.ausfish.com.au/vforum/showthread.php?t=136194

Im no expert but i can maybe give you some advice, where do you plan to go with it?

And are you gunna use it to launch off a concrete ramp? cause a decent offroad trailer isn't really meant for normal boat ramp use.
I use 2 trailers.

[lee8sec]

Eye to eye springs with swing shackles and fully welded and braced spring perches. Leigh

[nickstock]

It depends on what your version of off road is. My trailer is a happy medium. It is good for beach launching and has been towed on a few corregated roads.

Like flex said, full on off road trailers can be mongrals to launch by your self. Mine has good clearance, pupmed up steel work and I run Cooper st tyres on it. It is a good trailer for most of the fishing that I do. I have a fibreglass boat so I am a bit of a pussy to tow it on bumpy roads but a mate used it to take a 15 foot alloy boat up to Bathurst heads with out any major problems.

Nick

[Flex]

Double wrapped leaf springs is a must,
I used 3mm 100x75 Box section.
My axle assembly is held on by 8x 3/4 inch U bolts, which makes it fully adjustable and just as strong as welding.
Treg coupling is a must IMO,aswell as try and run the same tyres as whats on your vehicle.

The rest is pretty straight forward. I'd double the amount of rollers for more support aswell

The first offroad trailer we built was a split trailer, very good idea for an offroad trailer, allows you to launch it anywhere and maintain good clearance.

[ellis_d]

thanks to every one with there response.the trailer will be for mostly gravel roads just something that can cop rough corragations and the like.i dont plan on any super serious 4wd use.im planning on doing a bit of a treck up around the nt and north qld. hey flex when you say split trailer do you mean like a tilt trailer as i was thinking of making it like that to aid in launching and reovery thanks again

[Gilli]

Yeah mate tilt trailers are the go up here offroad. I know townsville aint that far north but the high banks of the creeks start around this area. My boat trailer is nothing more than a rule trailer with Light truck tyres on it but its a bit of a pain to launch on the banks of creeks or the beach, if i was you i would heavily consider a snap trailer (or tilt trailer as you might know it as). They are still reasonably simple in design, just need a decent pivot point.

regards,
Chris

[cormorant]

There was a bloke building camper trailer and boat trailers using independent coil springs that had like a pollyair bag in them. Let the air out and they had a very low launch or retrieve and pump em up and huge clearance and no axel in the middle nor huge tyres required.

Another bloke had a heavy duty transport trailer with stone guards and clearance etc but mounted on it he had a ally boat trailer with boat tied on to it. Hard miles done on heavy duty and local towing done on a lightweight normal trailer.

Cheap mate did a similar thing by just using an old car trailer as the trailer deck totally protected it from all the stones ( had a nose cone on it as it was used to transport a race car before) and larger tyres on car trailer are much tougher, boat rides on double suspension if you only strap tyres of boat trailer and hitch down. - he picked it up for $700 bucks and just raised the ride height a bit and it allowed him room for a couple of locked storage boxes for all the stuff you need and extra fuel so the storage in the 4wd can be used for normal family stuff. Motor was left in down position with a cover over it for the dust so no need for fancy motor supports. Straight overide brakes and they are built tough for 2000kg plus. Could upgrade to cheap electric caravan brakes as it will never go into the water so they would last. He reckons next time he will use a fully enclosed car trailer so he can leave it with a geneator running or solar and freezer in it for the catch and extra secure lockable storage around the camp. Spread the weight onto the trailer. Yep there is thieves everywhere even in the middle of knowwhere they turn up by boat , go through camp and disappear.

Stone guards are mandarory as boats cop a hammering. Even a couple of pieces of plywood on the front makes a huge difference

On a old trailer we painted it with sound deadner bitchimun paint to stop all the gal being sand blasted off the trailer and it worke OK

Think about running the remote radio tyre pressure sensors that are about now as it can save tyres getting shredded and the danger of trailer rollovers etc on dirt.

[hellfish]

Corragations are what will kill your trailer and your boat faster than any other road condition. Everyones first thought on building an off-road trailer is stronger(stiffer) springs. This is bad. Just take out the biggest hammer you have and bash the boat yourself. Look at ways you can soften your trailers susspension. Simply adding a set off shockies will improve dirt road travel greatly, but again not too stiff. Something like HQ holden rears are perfect for small trailers.

[finga]

Going down the road the other day I saw a trailer with a funny looking spring in the middle of the axle.
On closer looking it was just a spare attached to 2 hangers welded on the axle.
Not a bad idea I thought for long periods of bush roads.

Have to agree with hellfish too. You need the suspension to work.