SPUA in front and SPOA rear on Rocky? Good or stupid idea?

[BabyGodzillaGTi-R]

Hi guys i'm planning to do a HILUX LN106 axle conversion on my F85 Daihatsu Rocky. It will be leaf sprung over axle.. Used the search function to aid me in modding my Rocky and now very blur.

ISSUE 1
Shock mountings fundamentals.

Pro & cons, and reason why engineers mount the shock absorbers:
1. In front of axle (like my Rocky)
2. Hotchkiss style like a Toyota Hilux LN106
3. Inverted (many Outerlimit guys do this on their xtreme rigs.)

How should i mount my absorbers for the rear? I'm on a budget and would like to use back my absorbers that's currently on the car.... Its 22inch long. So should i go for method 1 or 2 mounting?

ISSUE 2
Can i do without a "traction rod" when I SPOA?
I just want something that will be a good compromise for off and on road and decent articulation.

ISSUE 3
I did some reading and notice some people install 4 Runner, Surf coil spring rear axles as it's wider.
Is it a straight forward conversion? I only have the housing and axles(halfshaft). Is all the rear axle parts interchangable between LN106 and 4 runner axles?

ISSUE 4
Is it ok if run 4 Runner rear axles only and standard width LN106 axles up front? Or my handling on and offroad would be very imbalanced?

ISSUE 5
I notice some people use their original steel rims an flip them over for wider offset. Safe to do so? I plan to run 35x10.5. I think the width of my rims is 6 inch. Is it still ok to use these rims?

Thanks in advance for answering my questions. Pardon me as I'm not a DIY person. More cyberoffroader than anything. I need the advise to give to my mechanic who's doing this project of mine.
Best Regards
Victor

[v6hilux]

Issue 1, Point 2 = The chassis is a stronger mounting location than the cross tube, but mine was changed to the cross tube 12 years ago and no issues exist to date. I needed to do it to allow a second fuel tank on the other side.




Issue 4 - If your referring to different wheel track widths front from rear, then there is a major safety concern on tarmac where longitudinal ruts form from heavy traffic usage. The vehicle will wander and even pull you to one side without warning. Very scary when you don't know it will happen the first time you nearly hit another car.

[Gwagensteve]

Manufacturers aren't all that interested in articulation when they mount shock absorbers, but they are VERY interested in preventing axle wrap. That's why the rear of any SPOA car (and some SPUA) run their rear shocks in the hotchkiss arrangement.

the 1st gen hiluxes ran their rear shocks as in v6hilux's photo. They only swapped to the hotchkiss arrangement with the gen2.

If you have short shocks and want to reuse them, use the "inverted" method (although I still don't understand why this method is called "inverted") shown in v6hilux's photo. By laying the shocks in at the top, you can get acceptable travel out of them. Be aware though that the more you lay them over, the softer the damping becomes. also, if the top mounts are very close together, the shocks become quite ineffective at controlling body roll. It's all a compromise.

Whether you need a traction rod will depend on your spring rate, spring length, traction, gearing, shock absorber valving etc. Generally, if you have a light vehicle, the spring rate you need for articulation and ride is too low to adequately control the axle, you you'll need a traction bar. Traction bar design is very fraught though and I still don't think I've seen a "perfect" design, epecially for SWB cars.

I understand that there is a ratio for calculating track width differences front to rear. Many cars run different reack width front to rear, but in a SWB vehicle, 3" of extra track width in the rear end can be frightening. You can do an IFS hub conversion on the front axle to match rear width.

6" is too narrow for a 10.5" rim.

Yes, rims can be flipped to achieve more offset.

Steve.

[BabyGodzillaGTi-R]

Thanks for some enlightening answers.
V6 Hilux, are those Gibson Ryders - Ultimate Suspension shocks?
I wonder is that company still around.

I'll be using Hilux LN106 leafsprings from Ultimate Suspension. I think they are fairly hard.
If i arrange my shocks the Hotchkiss way will my suspension travel be fairly limited?
Coz i notice my Rocky with the original mounts (front on axle) seems to outflex my LN106 Hilux but the Hilux is a fun car round tarmac corners in genral.
I'm considering mounting them the original way on the Rocky for simplicity....


ISSUE 4

I am genuinely interested in doing this wide track conversion but i'm still clueless what are the parts i need to get this going. I'm from Kuala Lumpur, Malaysia so i need all the advise i can get to source the necessary parts and i'll need to fabricate the spacers myself.

To date i only have the Toyota 4 Runner, Surf coil sprung axle tube and the halfshaft.
Can i just transfer all the rear axle components over from the LN106 axle to the Surf to make it a complete axle?

Did some searches i'm worried that the brake drums might not fit


Also what exactly do i need to increase the width of the front axle?
Search function revealed i need an IFS HUB. Does anyone have a picture of the HUB alone? Or do i need to purchase the whole Toyota Surf calliper unit?
Furthermore they say i need to machine a spacer.
Is there any websites that show a step by step detail on how to do the conversion so that i can guide my mechanic in this project.
What's the difference with the IFS and LN106 hub btw?
Or can i just machine steel spacers to increase the width?

Thanks for answer my newbie questions.

[v6hilux]

V6 Hilux, are those Gibson Ryders - Ultimate Suspension shocks?
I wonder is that company still around.

Yes they are Gibsons.

I got them 13 years ago. Don't know if they are still around.

[WACKO]

here is a link for doing the IFS conversion on the front axle. its step by step. its a very easy mod to do. i did it in 2 nights with very limited tools.

http://www.offroadexpress.co.nz/Forums/ ... =30&t=3543

Sam

[Twistinchassie]

not sure about the ln106 but the earlier lux'swith solid fronts, rear diffs are narrower by about 3inch overall (track) than the ifs front lux's rear housings.

im building a 85ln60 4runner and im using the rear housing out of a ln61 4runner (ifs front) to increase the track. plus the wider ln61 diff is a heaps stronger housing.

[BabyGodzillaGTi-R]

While i'm doing a SPOA in the rear i'm curious is it worthwhile if i install a Panhard rod?
I'm planning to use leaf springs all round.

I notice lots of Hilux owners install a rear traction rod. To my understanding it's to prevent axle tramp.

I'm concern my Daihatsu Rocky might not have the space to install a traction rod.
So would it be a good idea installing a Panhard rod instead?
Or they perform totally different functions?

I notice lots a people don't like Panhard rods in their dedicated off road rigs. Is there a reason for this?
I've the impression people would prefer an A frame (like the Range Rover), traction rod (Hilux) or a 5 link (LC 80 Series).

I notice lots of people slag the Toyota Bundera (3 link). I'm asking as lots of the rigs back in Malaysia use the Bundera setup.

Thanks in advance.

[v6hilux]

Traction (torsion) rods stop the diff rotating with soft springs. Lateral rods (pan hard) keep the diff located in coil setups.

Both can hinder articulation, especially torsion rods

[BabyGodzillaGTi-R]

So u're saying if my springs are relatively hard i can get away with a traction rod and a Panhard rod?

I notice on the front axle on my rocky have a Panhard rod but the rear doesn't have one.

Silly question, would a Panhard rod help reduce the diff rotating since i might not have the space for a traction rod?

Or the cheapest alternative to reduce axle tramp, diff rotating is to install the shocks in the Hotchkiss method? Or does this method really affects ultimate suspension travel/ articulation?

Am i right to say that if i install a Panhard rod i need to make it as horizontal as possible in relation to the axle so that articulation is not affected. Does it make sense? Or i'm being daft?

I can understand that suspension setup is always a big compromise but i would like some decent articulation too with my limited knowledge and budget.
Cheers

[v6hilux]

would a Panhard rod help reduce the diff rotating since i might not have the space for a traction rod?

Or the cheapest alternative to reduce axle tramp, diff rotating is to install the shocks in the Hotchkiss method? Or does this method really affects ultimate suspension travel/ articulation?

Am i right to say that if i install a Panhard rod i need to make it as horizontal as possible in relation to the axle so that articulation is not affected. Does it make sense?

Panhard rods keep the diff located correctly and stop left/right dislocation. They work in conjuction with torsion rods or arms usually. When big articulation is added, the diff will be pulled to the side it is bolted to the chassis opposite from the lowest wheel.

Hotchkiss will cause the diff to turn (tracking) when serious articulation is added, so inverted is the go. With serious power applied, Hotchkiss will dampen the rotation, but not prevent it.

[BabyGodzillaGTi-R]

Ok thanks for trying to make more sense.
I'm still trying to digest this article.
http://www.4x4wire.com/jeep/tech/susp/axlewrap/
http://www.pirate4x4.com/tech/billavist ... rapbar.htm

Might be an old article but still worth its weight in gold.

On the subject of my car since i'm worried the amount of engineering and thoughts needed to make an SPOA work properly, my mechanic was suggesting this setup.....
The front will be SPOA with the current Panhard Rod but the rear remain the same stock setup, SUA. Then we don't have to worry about additional links.
And try to balance/ make the ride height between front and rear equal by adjusting around with the spring mounts and shackle heights.
Does it make sense? Or sounds silly?

The current SUA setup using custom Ultimate Suspension leafsprings with shackles (3inch lift) is relatively flexy. Just that it can barely clear 31 inch tyres comfortably (Car is pretty low).

My aim ultimately to fit 35x10.5s with the provision to fit 36 x 12.5 comfortably. The flex on the current SUA setup at full travel rubs to body tremendously.
Some old pics of it flexing without rear shocks (they were too short and got ripped apart lol).


I admit that we're not very technically inclined and tend to learn things through trial and error and try to make sense to us what ever research material available online.

[BabyGodzillaGTi-R]

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