prado/surf SAS 4" lift custom radius arms

[mudsurfv6]

has anyone or know of anyone who has made their own radius arms? how did it work out?

there are a few that can be bought but aren't cheap.

radius-arms-comp-rods-79-series_3.jpg (2.66 KiB) Viewed 15224 times

can't be too hard for a competent engineer can it? need to be certifiable.

[Lchundy]

Do you want your truck road legal? have a talk to your certifier about it first.
I was thinking about custom arms when building my truck but certified wasn't really keen on the idea

[mudsurfv6]

Do you want your truck road legal?

yes that's the plan.

have a talk to your certifier about it first.

might have to, been on LVVTA forum asking but been nearly a year and still no answer.

[wjw]

might have to, been on LVVTA forum asking but been nearly a year and still no answer.

Phone them I got an answer straight away when I callled about my gearbox. As it's logged in their system they even give you a reference number in case anyone queries it.

[mudsurfv6]

they said replacement arms have to be same strength or stronger than originals, and preferably longer.

also asked about reshaping the brackets that the factory arms bolt into to keep castor right if I keep using them and they happy.

something like that.

[keithal]

they said replacement arms have to be same strength or stronger than originals, and preferably longer.

also asked about reshaping the brackets that the factory arms bolt into to keep castor right if I keep using them and they happy.

002.jpg

something like that.

if your going to the effort of custom arms wouldn't it make more sense to incorporate the castor into them than change diff brackets?

[mudsurfv6]

if your going to the effort of custom arms wouldn't it make more sense to incorporate the castor into them than change diff brackets?

yes, sorry obviously I wasn't very clear. if I go custom arms then that's what I would do. if I stick with the prado arms then I would change the brackets on diff.
just need to figure out which its going to be.

[Clint]

they said replacement arms have to be same strength or stronger than originals, and preferably longer.

also asked about reshaping the brackets that the factory arms bolt into to keep castor right if I keep using them and they happy.

002.jpg

something like that.

You probably can't angle the arms up very far on the diff like that without them hitting the steering tie rod that sits above them. You can see the custom arms in the pics above have a big kink there to clear the tie rod.

Cheers
Clint

[mudsurfv6]

You probably can't angle the arms up very far on the diff like that without them hitting the steering tie rod that sits above them

tie rod is in front of the diff.

[Clint]

You probably can't angle the arms up very far on the diff like that without them hitting the steering tie rod that sits above them

tie rod is in front of the diff.

No worries then My LJ71 had it behind but hilux/surf must have it in front? In that case you'd probably be better off making your own vs aftermarket lift prado arms as you could make them without the kink & they'd be stronger.

Cheers
Clint

[mudsurfv6]

No worries then My LJ71 had it behind but hilux/surf must have it in front

yeah heaps of room.

surf do up to 1995 (ifs), beam axle were only made 1984-86, and hilux to 1997 then its steering rack behind diff. (someone say if I'm wrong).

but mine has prado/hilux diff, 80 series LC steering box and 70 series LC tie rod and drag link.

[Lchundy]

When I was searching internet for ideas for radius arms on my wagon I did find a 80 series that had factory radius arms mounted upside down to the top of the diff,but that idea was to clear steering arms
They way it was set up gave it good caster and it ended up moving diff forward slightly
I ended up using aftermarket bolt in arms so didn't really look that far into it but might be worth seeing if it will work for you

[mudsurfv6]

went and had a look after reading ^^ and looked at drivers side and thought it might work but looked at passengers side and maybe not. the panhard might be in the way when the left wheel goes up, depends on how high the arm sticks up, but will look into it.

[Sausager]

I don't see why these would be hard at all. Do they have to be one piece, or can they be fabricated?

[mudsurfv6]

Do they have to be one piece, or can they be fabricated?

all LVVTA have said is 'they must be as strong or stronger than current arms' so whatever is going to work. some of the manufacturers of these arms say one piece is stronger and welding is weak but they probably just want to sell theirs.

[Clint]

The way I'd do it would be to design them to suit your build exactly, machine up the diff end bush housings (or hack them out of some old suspension links if you can find some the right size) get the arm profile cut from 30mm plate with holes to weld your bush mounts into.

The chassis end is where it gets tricky as there are cool super flexy, tough & rebuildable joints you can get that would be ideal but you're not allowed greaseable for cert & I think most of them are. So you could just go with another rubber bush (80 series style NOT GQ pin style) or drill & tap for a big rod end like the 25mm SKF ones I adapted on to my Nissan arms but a male thread. Maybe weld plates either side of the hole to strengthen the thin bit.

Cheers
Clint

[Lchundy]

I wonder if the stock 80 series radius arms are longer than the prado ones
I've looked under a prado and the 80 series arms look more stronger built
Could be a cheap option.

[mudsurfv6]

I wonder if the stock 80 series radius arms are longer than the prado ones, could be a cheap option.

I'm not 'too' worried about the length, though a bit more would be good. its the angle they rise away from the diff end, keep standard angle at diff but lift chassis end up.
do you know if 80 same shape/angle as prado? are the mounting holes at diff the same as prado?

The way I'd do it would be to design them to suit your build exactly, machine up the diff end bush housings, get the arm profile cut from 30mm plate with holes to weld your bush mounts into.

that looks like the plan.

The chassis end is where it gets tricky, you could just go with another rubber bush (80 series style NOT GQ pin style)

I would imagine that would be the simpler rather than a rod end. its not set up for huge amounts of travel, that's for another vehicle sometime.....

[axel]

80 series radius arms are almost identical shape to prado 1s but definitely a stronger unit. I have a photo somewhere showing the 2 overlaid. From memory the 80's r about 5-10mm longer with a slightly steeper?? caster angle if used on prado mounts.

[mudsurfv6]

I've got prado diff but custom mounts at other end which need to go up about 150mm, without measuring it.