flipping axle on 6x4 trailer

lefty

lefty

Forum Member
Joined
Jul 11, 2008
Messages
900
Location
Perth Australia
Car Year
MY05
Car Model
Forester
Transmission
XT lux manual
I have a 6x4 box trailer for general garden use for mulch/dirt. I don't use it camping or offroading. I am finding that the suspension is bottoming out when the box is only 75% full with dirt.
Is it an easy DIY process to flip the axle so the leaf springs sit over the axle without specialised tools?
or
Any recommendations for a shop to do this in Perth SOR?
 
Gidday Lefty

A couple of things ...

1) when your 6x4 is three quarters full of dirt, it's probably well over 750 Kgs. Specially if it has 500 mm sides!

2) to flip the axle, you need to remove at least one hub. It will be far easier if you remove both ...

3) flipping the axle is otherwise quite straightforward. It will be a LOT easier if you have someone to help. Just make sure that you align the U bolt fish plates properly over the pins on the springs. You may have to make up a small fish plate for the top of the axle where it contacts the spring.

4) while you have the hubs and bearings apart, take the opportunity to give them a really good clean, inspect and re-grease with good quality wheel bearing grease. Do not use marine grease unless you use your trailer in salt water! It isn't as good as normal wheel bearing grease, just better at repelling water ... Probably a good time to replace the rear bearing seal in the hub.

5) tighten the hub nuts properly after refitting them. Too tight/loose will bugger the bearings, and possible break the axle stub.

Tools needed are normal spanners and a 10-12" shifter for the hub nuts.

When refitting the U bolts either use new Nyloc nuts or double nut them. I prefer double nuts. Tighten the first set of nuts in crosswise order to about 50-60 ft lbs, then holding the first nut with an open end spanner tighten the second nut down on it to the same torque. This will lock them together. I use a flat then spring washer under the first set of nuts. In about 50 years, I have never had a U bolt nut come loose ...
 
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I do the same but i usual double nut with a nyloc on the outside. Not sure if It's any better but doesn't hurt (unless the nut is over 18mm my bolt shop charges the same for nylocs or nuts.
 
I have a feeling it's not quite 750kg, it's my first trailer so I'm not sure.
This is it bottomed out with dirt (no rubble) in the box. The sides are 35cm high
Doesn't even look 75% full???
16483584556_ffdc35cdc5_c.jpg


15889419733_0db9911d50_z.jpg


this is from underneath, it's supposed to be heavy duty but why does it bottom out so easily?

15887015224_fbab0bed2b_c.jpg


side view - note my right rear strut is shagged

15887013424_bc91f7be41_z.jpg
 
Gidday Lefty

I estimate that there is roughly 670 Kgs of (very sandy) soil in your trailer - 1.220 x 1.828 x 0.25 x 1200 Kgs/cu.m. = 670. If filled to level at the top, that weight increases to around 940 Kgs for the soil. If it is damp, increase the 1200 factor to 1450 ... !

Add the estimated weight of the trailer at 270 Kgs, and there is 940 Kgs ...

Those springs do indeed look mighty heavy duty, but it's not their size that determines their carrying capacity but their rating. Judging from the provision of the shock mounting point on the lower fish plate, I am guessing that they may not have a very heavy rating. Perhaps as low as 500 Kgs per spring. That could explain the bottoming out.

How do the springs sit when empty?

I had around 0.75 cu.m. of damp sand in mine once, for less than a kilometre at about 40 kmh. That was around 1120 Kgs, plus about 250 Kgs for the trailer (then - about 30 years ago). That load bottomed out the springs like yours. They are rated at 12 cwt each (originally), about 610 Kgs each. My trailer is a 7x4 with 300 mm sides, but it was heaped!
 
OK, Lefty.

In that second shot, the rear slipper part of the spring should be inside that piece of box section, not under it.

That will make your problem worse, not better, but it needs to be inside for safety reasons. It stops the rear of the spring from being free, i.e. restrains it when there is rebound.

This being the case, it seems that there is something very wrong with how your suspension and springs are set up.

The spring also seems too flat for all those leaves. Maybe the front spring hanger is the wrong length??

Take it to a trailer expert. He will tell you immediately what the problem is, but I can tell you that you have got one!
 
^ Further to the above, I've just realised that your springs are fitted backwards!!

The slipper part is meant to be at the back of the trailer, and the eye of the spring and spring hanger should be at the front ...

Mate, this is seriously dangerous.
 
wow ok thanks for the info
I will bring it into a shop next week
 
Glad I saw it.

It wasn't until I realised that the front upper frame was at the wrong end in relation to the way the springs were facing!
 
RB, are you SURE it is a slipper? Normally a swing-link one end means it's not. (My bro used to build'em for a living).
 
Not absolutely certain, of course.

But if you look at the front end in Lefty's second photo, the end of the spring is pointing downwards, the way a slipper spring does.

A slipper spring with a shackle at the other end will act as a slipper spring (to a degree) at both ends. With any load at all, it will try to flatten itself the way Lefty has described it.

Only Lefty can tell us for sure, or post some photos of both ends of the spring, and one of the complete spring from front to rear taken from the other side of the trailer underneath.
 
I would have thought (?) that a slipper with a swing-link (what I've always called them) is going to have location issues. The swing-link is gonna head fore or aft and sit horizontallish. Dunno.

Over to you Phil - what exactly is it?

Also, are those 5x100 hubs or some "foreign" size?
 
Lafty,

Let us know what type of springs they are they look like shackle springs to me. Dr Google is your friend

So they should have have an formed eye on each end with a shackle on the trailing end.

If they are the easy way to get a bit more clearance is to fit extended shackles.
 
hub is Holden from what I've been told 5x112 ? Definitely not 5x100 I've tried a Subaru rim and it's a no go.
Tyres are 15"

left is back, right is front

16345834760_a42fe715e7_c.jpg


closeup of front

15913113743_911cd68500_c.jpg
 
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Thanks, Lefty.

Sorry for alarming you unnecessarily. That's exactly how the front and rear should look. Doesn't explain the ease of overloading such a very heavy looking spring though ...

As I said before, a decent trailer place will tell you almost immediately what your problem is being caused by. They see more trailers in a week than most of us will look at in a lifetime!

Good luck with sorting it out, mate.
 
Lefty,

Yep shackle springs - longer shackles are available for a trailer place to get you wheel clearance - bet the trailer was built for 13" wheels with Holden rims and that is why you have a clearance problem.

The springs should have some bend when filled to the rated load - if they are flat you need higher rated springs. Remember with out brakes 750 kg is all you can put in the trailer so new springs may not do anything except make the ride of the trailer harder and convince you the trailer is not overloaded when it is.

If Ratbags calcs are correct the springs are probably about right. - Did I hear someone say INSURANCE.

When I tried to replace my trailer springs found out they they were imperial sized and it was going to be a pain - to get new ones to fit I would have to move one of the mounts. yada yada. I haven't changed them.

Good Luck
 
Gidday Dave

crazydave said:
Lefty,

Yep shackle springs - longer shackles are available for a trailer place to get you wheel clearance - bet the trailer was built for 13" wheels with Holden rims and that is why you have a clearance problem.
Click to expand...

Probably. That's what mine originally had - 165/85 13, or similar. I was quite pleasantly surprised when I worked out that the 215/60 16 would fit. I didn't want to interfere with the guards. I miked them at 4 mm thick. No chance of bending that by jumping on them!

Because my trailer axle is very slightly off square, the P/S wheel now just touches the rear of the mudguard under extreme provocation at speed, off road. I fixed this by welding a bit of 6 mm bar into the slipper box on this side, between the spring and the chassis. That's all it took.
 
thanks for all responses. The trailer is a refurbed one that is about 20-30 years old so the 13" rims is probably right.

I guess the easiest option is to simply get 13" rims?
2nd choice is to get extended shackles as suggested.
Flipping the axle is the least attractive option as the trailer will be too high for the Foz.
 
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