4x4 Boat Trailer Conversion

[Joe Devereux]

I am considering converting my standard boat trailer  to a 4x4 version. however I am concerned about the trailer being to high to launch. I am considering a "step down axel" to compensate for the rise in height, however it looks like this would be where the axle might bend. The reasons I want to convert my tailer is my 14" wheels are just not handling the roads as well as what I would like. Has anyone done this on there trailers and how did you compensate for the rise in height. My boat is 5.3 seajay and needs about ⅓ of the trailer in the water to launch and retrieve I have measured it and I can just fit some 17" hilux wheels on it and be legal.

[rayke1938]

Are you thinking of replacing the axle or just cutting your existing and using a dropper?

I would assume that your existing axle is braked with a 5.3 boat on it.

You should have a 50mm square axle which is 2 tonne and should not bend. If you are worried about it bending just weld a rib onto it.

You can usually pick up a second hand axle from a caravan on gumtree for a reasonable price.I got a 45mm square drop axle for 10 bucks that i shortened and put under my boat trailer to lower it.

Cheers

Ray

[Binder]

I'm not understanding what you are wanting to do, you want to raise the boat / trailer by fitting taller tyres for off road clearance I assume, then drop it all back down again by using a dropper axle?

 

[Joe Devereux]

I know it sounds a bit odd by installing taller tyres and dropping the trailer back down with the drop axle. I am not chasing clearance, allthough this is an added bonus. what I want to achieve is a trailer that is capable of hundreds of kilometres of corrugations without ruining my tyres. 4wd tyres I feel would be the way to go, because I have had no dramas with my tyres or wheels on my hilux, and spare wheels on the car could be used etc. My biggest concern is the trailer being to high to launch or retrieve it so again I go back to a drop axle, I don't want to back my car into the water!!!

4 hours ago, Binder said:

I'm not understanding what you are wanting to do, you want to raise the boat / trailer by fitting taller tyres for off road clearance I assume, then drop it all back down again by using a dropper axle?

 

[rayke1938]

Why not just install a good brand 8 ply light truck tyres on your rims they will only have a slightly higher profile?

Cheers

Ray

[Binder]

I upgraded the axle under my boat and went to light truck tyres. Got a donor trailer with the axle and rims and tyres cheap as the frame was rusted out, but had no suitable spare (having gone up to 14 inch tyres from 13's)

Believe it or not I got a good light truck tyre on a new rim delivered from Melbourne cheaper than I could get the same tyre fitted in Qld, little own buy a rim...... good old ebay to thank for that.

But one advantage you would have is certainly having to carry less spares / able to recycle the tug's tyres down to the boat etc. Fair amount of work though.

 

[Angry51]

1 hour ago, Joe Devereux said:

I know it sounds a bit odd by installing taller tyres and dropping the trailer back down with the drop axle. I am not chasing clearance, allthough this is an added bonus. what I want to achieve is a trailer that is capable of hundreds of kilometres of corrugations without F&*$ing my tyres. 4wd tyres I feel would be the way to go, because I have had no dramas with my tyres or wheels on my hilux, and spare wheels on the car could be used etc. My biggest concern is the trailer being to high to launch or retrieve it so again I go back to a drop axle, I don't want to back my car into the water!!!

 

Joe, 

       What bearings do you have on your trailer now?

                         Gary

[Joe Devereux]

Gary

I have ford bearings and 14" rims with light truck tyres already NT dirt roads are pretty tough going. Oh and I'm not driving at light speed on the dirt usually sit around 60-80kph (depending on road conditions) I was sitting around 45kph on my way to gove it was torture when all you want to do is get there.  if I was to change I would be using Landcrusier or hilux bearing equivalent. 

joe

[Joe Devereux]

Here is a pic of one of the tyres i blew I didn't here it or feel it, caught it a little to late to save the rim. It happened just near the roper river. tyres were a light truck. I saw a trailer made by Seajay on the weekend However it cost the owner 40k just for the trailer no boat I am not as rich as him but he has inspired me.........he said just do it.........easy to say when you have money

joe

[Binder]

You have certainly done a good job on that rim!

 

[rayke1938]

Looks like if you upsize your rims with a drop axle you will be up for new guards and spring carriers. You may be able to just unbolt the rear of the guard and jack it up and rebolt it. Another thing to watch is the offset of your new rims.

Cheers

Ray

[Angry51]

Joe, You can just swap your hubs out with landcruiser hubs / Ford bearings.

Then put whatever size tyre you want on it. If your springs are underslung you just put a block between your spring and axle,

that will leave your boat at the same height. Give or take an inch or two. Might have to adjust mud guards.

This is what I did on flat top trailer to match trailer tyres to my Nissan Patrol, which also makes the trailer same height as my tray 

on Patrol.

      Gary