Thread: My Trailer Build - Car carrier

Here's a link describing measuring axle length from an Ebay seller.

eBay Shop - Spinny Things Trailer Parts: TECHNICAL GUIDE

Nev

Firstly, Welcome.

My first concern would be what you're going to cart on that sized trailer. The 45mm Slimline axles on 6 stud pattern wheels, even with load sharing suspension, will give you 2600Kg total capacity. Minus trailer weight, say 700Kg, giving you a payload of 1900Kg... barely enough for a late model Commodore or Falcon, let alone anything bigger.

If you don't want to go the extra expense of 12" Electric brakes, then suggest looking into Parallel bearing'd axles. Machined on 50mm Sq material, they'll give you 3200Kg for less than what you saved on steel costs.

The link to the ebay site has some good info, but don't try and give an overall length when ordering an axle, unless you know exactly whose brakes and hubs the supplier is using. Better still, contact a manufacturer, such as Melbourne Trailer & Caravan Supplies, direct. Give them a 'Face-to-face' measurement and they'll calculate the rest.

By my quick calculation, if your tyres are exactly 255mm, and are exactly 30mm offset, and sit exactly at the 2500mm legal outside width, then your face-to-face is 2305mm. You're measurement of 1930mm deck space is also what I came up with, but 30mm a side clearance is extremely tight on a tandem. Next time you see a loaded tandem turn a tight corner, you'll see why.

Looking forward to seeing progress shots.

Cheers,
Yonnee.

Thanks for the good advice.

I am a fan of over engineering so lets have it!

Realistically 2t would be the maximum I would be towing. I like to have a car on the trailer, not hanging over the front and back which is the main reason for making the deck larger. I also carry bulky loads that dont weigh alot. example olive trees out of werribe, usually a few thousand at a time where the more space you have the better.

My vehicle is an 09 hilux deisel and is rated to tow 3.5t braked. I've towed a fairly large load before and she loves it. Being able to start in low range and change to high on the fly is great. Little less wear on the clutch. Interesting bit of trivea, I can do 9l/100 on the geelong road normally, towing an empty car carrierincreased to 11.4l/100 then with a 1500kg car on that only increased to 11.8l/100. Fantastic vehicle.

Anyway a bit off topic...

DIY Tandem Axle Kits

What would be wrong with the 2.8t kit. Why do they still rate it at 1.4t / axle even with the larger hub combination?

The comments on the width and also the tire to chassis clearence has me worried now. I know there is a great deal of flex when turning. Is this in the rim or axle / spring itself? when i've towed other trailers it looks like the damn wheels will snap off with a 14 inch steel rim type setup and I was always mindful of avoiding sharp turns where possible.

How does a parrallel bearing deal with side loads?

Originally Posted by 09sr5

My vehicle is an 09 hilux deisel and is rated to tow 3.5t braked.

This is an interesting comment because as far as I know and according to Toyota Specs for both 4x2 & 4x4 you can only tow 2.25T Braked with a Hilux.

Maybe you're thinking of the Cruiser as they are rated at 3.5t?

Originally Posted by DJ's Timber

This is an interesting comment because as far as I know and according to Toyota Specs for both 4x2 & 4x4 you can only tow 2.25T Braked with a Hilux.

Maybe you're thinking of the Cruiser as they are rated at 3.5t?

Your right, std towing is 2.25t with HD tow bar it is 2.5t. 3.5 t? My bad typing quickly at that time of night.

Ok so today I went and visited Marchall engineering. They measured the tires gae some helpful advice.

I have bought a 3.2t kit from them. They dont list it on their website but do have it as a kit.

The kit is:

2x 50mm square axles
1pr 3.6t 60mm 7 leaf rocker roller spring sets to suit 16" wheels Alko 6.5mm thick leaves
Tandem spring fitting kit (high tensile U bolts)
4x 10" electric hub drums using parrallel bearings
2pr electric brake assemblies
electric brake flanges
3.5t electric coupling
cable adjuster, cable, clipsetc
breakaway system


I need 95" axles

One thing that i need to do is send a wheel nut for the hilux alloy. They have a unique nut/washer so to be sure they have the right studs they need it.



Internal dimensions will be 1900 wide now, the tires were actually 245 wide and they are allowing 42mm between the tire and chassis Overall width will be 2474.

They are busy but really helpful people.

Originally Posted by 09sr5

Thanks for the good advice...

...What would be wrong with the 2.8t kit. Why do they still rate it at 1.4t / axle even with the larger hub combination?

Technically, they'd run into some trouble advertising them as 2800Kg and listing the option of 16" wheels in the same section, if someone were to take them to task over it. Technically, it's a 2600Kg kit on "Off-road" tyres (15's or 16")

The comments on the width and also the tire to chassis clearence has me worried now. I know there is a great deal of flex when turning. Is this in the rim or axle / spring itself? when i've towed other trailers it looks like the damn wheels will snap off with a 14 inch steel rim type setup and I was always mindful of avoiding sharp turns where possible.

It's really a combination of everything that moves and flexes. The tyres flex, the alloy rims will flex a little, the springs, hangers, axles... Even if each one were only 5mm... that's a whole inch when added together. I wouldn't worry about it too much unless you consistantly overload the trailer. The ratings on the springs and axles are set with all this factored in.

How does a parrallel bearing deal with side loads?

Not quite sure what you mean by this question... The Parallel bearing setup is pretty much the same as a standard Ford/Holden axle bearing arrangement, but the outer bearing is the same as the Slimline inner bearing. The hub is cast to accomodate the larger outer bearing as well as the '2 tonne' grease cap, and the axle uses the '2 tonne' slotted nut. So where the weak link with the Slimline axle is the outer bearing journal, this is now enhanced with the larger bearing, hence the greater capacity.

Ok so today I went and visited Marchall engineering. They measured the tires gae some helpful advice.

I have bought a 3.2t kit from them. They dont list it on their website but do have it as a kit.

The kit is:

2x 50mm square axles
1pr 3.6t 60mm 7 leaf rocker roller spring sets to suit 16" wheels Alko 6.5mm thick leaves
Tandem spring fitting kit (high tensile U bolts)
4x 10" electric hub drums using parrallel bearings
2pr electric brake assemblies
electric brake flanges
3.5t electric coupling
cable adjuster, cable, clipsetc
breakaway system

I am a big fan of Rocker Roller springs. Much less wear and tear, and less maintenance than a shackle set. Simpler to set up too.

One critical thing with one of these kits... welding the brake flanges to the axles. To avoid brake dramas further down the track, it absolutely imperative that they have the correct setback, and are square. In my vast experience with Electric Brake troubleshooting, a major cause of lack of brake performance was due to incorrect adjustment. And this is nearly impossible to achieve with incorrectly aligned flanges.

Find out if Marshall's have a jig and get them to weld them on. Otherwise, be very vigilant in your measurements in setting them up. Check, re-check, tack one corner, check, re-check, tack opposite corner, check, re-check... repeat two remaining corners, then weld.

I will pay them the $150 to assemble then!

Thanks for the heads up.

Ok so a build thread is useless without pics...






Steel for the chassis cut and laid out in approx positions. My shed is small I know and I promise I didnt make it to suit the shed! I fluked that bit. I havent cut the front and rear cross members yet. They are the offcuts from the chassis rails.

I assembled the chassis rails and cross members and tack welded in place. Measured up corner to corner to corner to check for squareness. Then welded the cross members top and sides. will flip the chassis over tomorrow and weld the bottom.

I need to send a wheel nut to Marshall engineering in Bacchus marsh who are the crowd I am buying the kit from. The hilux alloy uses a unique wheel nut with a shank and washer. Marshalls want to make sure they put the right studs in the hubs. Transferred them the money and set the ball in motion. The axles take 7 - 10 days apparently as they custom make them.

That's awesome!!
Looking forward to seeing the rest of the build.
Thanks for letting us in on all the action.
Cheers

Flipped the frame over today and welded the undersides of the cross members.



Came to a minor hitch



Had to go out the other door which was a minor inconvenience. Anyway.

Cut some corner gussets from the 100*50 RHS



And cleaned up



and welded in place



as it sits now



Tomorrow I will cut the drawbar and mount. I spoke to Marshall engineering and they have gone ahead and ordered the hubs with M14 studs without getting the wheel nut yet. If it is wrong they will get the right ones and put the others on the shelf. Hoping it's right otherwise it'll be a delay. I dont have a set of calipers to measure the studs.

I'm not sure if you need M12 or M14 studs but make sure they also get the length right. Too short and you will not have enough thread engagement and too long will bottom out in the nut before the rim is seated on the hub.

Nev

One critical thing with one of these kits... welding the brake flanges to the axles. To avoid brake dramas further down the track, it absolutely imperative that they have the correct setback, and are square. In my vast experience with Electric Brake troubleshooting, a major cause of lack of brake performance was due to incorrect adjustment. And this is nearly impossible to achieve with incorrectly aligned flanges.

Totally go along with that. Thats one thing on the horsefloat project that I left for the trailer place to do. Then its a simple matter of checking ones clearances on the trailer frame wrt the wheels and weld the spring mounts up etc....

See if u can smoke the tyres up on the maiden voyage Those electric brake sure are effective.

Nice Chassis.

Their very helpful over at Marshall's. I've got a few bits from them and a couple of mates have bought kits from there, very helpful and more than happy to answer any questions or give advice. Just like you Yonnee!

Also with the electric brakes, don't do what I did. Replaced the old mechanical brakes on my caravan with electrics (along with springs, axles ect). Fitted everything up, jumped in the car and headed off for a test drive, jumped on the brakes and nothing. Well almost nothing, they barely worked, figured the new shoes and drums needed to bed in. So kept driving and braking, including riding the brakes by pressing the button on the brake controller, after 1/2 an hour the brakes felt no better.

Rang a mechanic mate to help me trouble shoot the problem. After going through a range of things he then said "did you clean the machine oil of the new drums before installing?", did I what, woops!
Machined bare steel surfaces are coated with oil to stop them rusting.
The shoes had completly glazed over and the drums were looking a bit average. A good scuff with some emery paper on both shoes and drums, then wiped clean with some prepsol and I was locking wheels 2 minutes later down the road.