More flex for the front of the Series

[o_teunico]

Hi all,

This is a spin off from my 88" rebuild. After Bill´s coments on how some front shackles will improve vehicle´s traction on goat like terrain, and also after seeing Koos´ (Toyroverlander) suspensión setup (longer front overhang and longer front leafs) I have decided to try something in my vehicle, since front dumb irons are in very poor state and will need welding anyway.

Using a rear quarter chassis, I will enlarge the front overgang so I could fit some rear leafs at front. SOA and bigger tyres will make the loss in aproach angle less evident. Quite probable I will need some degree shims for having the correct castor angle.

This is the mock-up I have made with the Six cylinder spare chassis we have. I have forwarded the pictures to an engineering company so they can tell me if this could be made road legal in Spain.

Any ideas or advice on this setup?

[Soren Frimodt]

Yeah I don't see why it wouldn't work. With regards to overhang, if you trimmed it down to the shackle mount as the factory dumb irons, you'd probably not even have more overhang than a Defender. Remember that their front axle sits much further back than on a leafer. And you might also get in some trouble with the swing shackle, the chassis isn't kinked or recessed where it'll land up so it will give a considerable lift, worth having in mind with your SOA plans..

[missingsid]

What are you doing with the spring mounts, are you going to use the rear spring mount as shown (shackle in the front) or are you going to rebuild the front hanger on the chassis extension?

[o_teunico]

Shackles at front, with rear leaf mounts welded under chassis (taken from the rear of a 109).

I have considered triming the bumper/crossmember, but if I live it as is I will have a nice winch base and any obstacle will be hitted first by bumper and not by shackles.

[ToyRoverlander]

Shackles at front, with rear leaf mounts welded under chassis (taken from the rear of a 109).

Very interesting! Can't wait to see it finalised and in action. I'd love to hear your comments regarding handling on the street and offroad when it is finished.

I would suggest fishplating the sides of the chassisrails to add some extra strength at the welds, even if it is for peace of mind.

If I look at the fourth picture above one thing I would change is the height of the shackle bush on the chassis, with the same length shackle, so the spring sits higher in the front. That way the spring eyes are more level. Gives the added benefit of the shackles being less exposed and it lifts the front end less.

[Anderzander]

How much further forward will it move the axle ? Do you have any plans for the bodywork to accommodate that ?

[discomikey]

i would imagine a SOA will give you more hassle than its worth as that already shows an estimated ~6" lift, youll struggle to package everything without major surgery to the steering, propshaft, maybe engine/gearbox mounts too.

just my 2p, i like the rear springs idea though, i think youll find the front wheels wont look "stupid" with that overhang even without SOA

[discomikey]

How much further forward will it move the axle ? Do you have any plans for the bodywork to accommodate that ?

dont know what santana's are like but with 32" tall tyres there isnt much room further forward in the wheelarches, especially on the back axle.

[ToyRoverlander]

The axle can be put where ever he wants, that just depends on where he positions the springmount.

i would imagine a SOA will give you more hassle than its worth as that already shows an estimated ~6" lift, youll struggle to package everything without major surgery to the steering, propshaft, maybe engine/gearbox mounts too.

That's doing it properly so it doesn't end up being a danger to others and the only way to do it so it functions properly and by doing it that way it most definately IS worth doing it. People should really have a go in one before knocking it. Done right it makes an incredible difference, in a good way.

[Anderzander]

That's kind of my thinking Mikey.

Would it be worth centring the axle location by moving the rear spring hanger back ? It would mean standard props, no body mods needed and reduce the amount of extra length at the front.

[discomikey]

The axle can be put where ever he wants, that just depends on where he positions the springmount.

That's doing it properly so it doesn't end up being a danger to others and the only way to do it so it functions properly and by doing it that way it most definately IS worth doing it. People should really have a go in one before knocking it. Done right it makes an incredible difference, in a good way.

im not saying dont do it theres only meant to be 6984 rivets on a land rover, i love technical mod threads, in fact have read through your truck thread, and love the engineering there, i just know that being such a short truck, it might complicate things a bit more than your (used to be) 109.

my series is on parabolics and i already cringe at the rear prop angle haha its that kind of stuff that can be solved a lot more easily on a LWB where a SWB could create more hassle than the mod is worth thats all.

[ToyRoverlander]

You're right, with a swb it is a different story than with the longer 109. I must admit I totally forgot he was doing this to a swb as apposed to lwb, my bad. Being a swb it takes a bit more thought to not end up with a tall wobbly unstable vehicle. Still doable though. He could even push the axle back a bit, as standard it actually looks likes it's sitting a bit in front of the middle of the wheelwell. I pushed the axle back 2" and it doesn't look out of place though a trained eye will notice it. Push it an inch back and it looks perfect.

And as always, best to try and keep the lift as low as possible.

Side view of mine. Rear axle pushed back 2", front axle forward 1" . Lift as little as possible, sitting on 35s.

[o_teunico]

Pictures are just a mock up. Front overhang is extended to the exact measure to leave the wheelbase as stock. Also note that the rear leaf used at front is with no weight on it and uses 1 Ton extended shackles. In real life it will have probably just two leafs, sitting nearly flat, and standard length shackles.

The engineering company has said me not to weld anything to my chassis yet, as they are still consulting with a mechanical lab to see if this "major chassis moddification" can be made road legal, so I will wait for their reply before making anything that could not be reversed to stock.

I have asked them to take in account this setup in two forms: with and whithout SOA.

My 88 left the Linares factory with a 5 speed LT85. That means that my rear prop is already a doublé cardon type. Pointing diff´s nose directly to box output will solve any transmissions problema associated with SOA lift.

[ToyRoverlander]

Dont go with just 2leafs, waaaaay to soft. I wouldnt use anything less than a 3leaf, how arched it ends up depends on the condition of the springs. Mine are fairly flat. If going soa, make your spring perches long, like 25cm long, this helps reduce springwrap.

Also, consider raising the front shacklebush and use one-ton shackles.

What shocks do you intend to use?

[o_teunico]

You use three leafs, but yours is a 109" with a big 3.4 engine. Mine is 88" with small 2.25 diesel. Leafs are from the rear axle of a 109 Six. Are rated to slightly more tan 2000kg. 1000kg rate with two leafs should be OK for the front of the 88. Anyway, I could allways refit one of the taken away leafs.

Rear trailing arms from a coiler can be used for fabricating some anti-wrap bars (something similar to what Soren made).

According to my calculations, 12" shocks wouldn´t need new shock mounts when used with SOA and 4" bumpstop spacers. ProComp are the only ones that fit my budget.

[bill van snorkle]

I doubt you would be able to get away with rear springs reduced to 3 leaves, especially if you intend fitting a winch. I have military LWB springs reduced down to 4 leaves on the lighter rear end of WildFing and they sit slightly reverse arched, so I will be adding a 5th leaf.

It would be nice if your authorities would allow you to recess the front spring hangers up into the bottom of the chassis rails so that you can keep the effective lift down to the minimum without going to reverse arch springs. The rear on a SWB is much easier, because it is possible to build off the spring hanger to place the spring eye 6" higher, and at the back to weld shackle bush tubes higher up in the chassis rail itself to even completely negate the 6" or so lift that the SOA will give if you wish. This would still give the benefits of having the underside of the axles relatively snag free, and giving higher suspension roll centre, without raising the vehicles centre of gravity.

The other suggestion I would make is, rather than lift the whole chassis/body unit, to do some detail work on the number 2 and 3 crossmembers , so that nothing hangs down below the chassis rails.The centre of gravity may go up a bit due to raising engine/trans but not as much as lifting everything.

[o_teunico]

Trimming/raising the lower parts of chassis was something I thought, but I´m not allowed to cut the chassis. Weldind extensions without cutting the original chassis seems OK to authorities.

My front parabolics (Factory fitted) are only two leafs.

[bill van snorkle]

Trimming/raising the lower parts of chassis was something I thought, but I´m not allowed to cut the chassis. Weldind extensions without cutting the original chassis seems OK to authorities.

My front parabolics (Factory fitted) are only two leafs.

Parabolics are different to semi elliptics and wouldn't tolerate permanently altering their designed arch by running ones too light for the job. Semi Elliptics due to the leaves being thinner have less surface tension when they are flexed, so they are more forgiving and less brittle when flexed outside of their design parameters.

[ToyRoverlander]

2 leaf front parabolics are almost always too soft. Just about all the one's I've same are almost flat with very little distance between the axle and bumpstop.

Bill, I guess I must be lucky then. My brittpart parabolic springs have survived about 5years of severe reverse arching and serious torsion without any issues.

I've tried 2leaf rear springs up front. When just fitted it seemed fine but after some more use they sag a lot and need a 3rd leaf.

[bill van snorkle]

2 leaf front parabolics are almost always too soft. Just about all the one's I've same are almost flat with very little distance between the axle and bumpstop.

Bill, I guess I must be lucky then. My brittpart parabolic springs have survived about 5years of severe reverse arching and serious torsion without any issues.

I've tried 2leaf rear springs up front. When just fitted it seemed fine but after some more use they sag a lot and need a 3rd leaf.

Or maybe I was just unlucky with a spate of failures with Ford Transit parabolics on the back of WildFing a few years back.

[ToyRoverlander]

Perhaps. I don't know. I guess it's better to try and not reverse arch them at all. Adding the 3rd leaf sure helped with that.

What I do like to add is that it is a good idea to start stockpiling spring bushes as they will be very short lived on the shackle side of the spring. Doesn't matter which ones you use, when using all the flex the springs are capable of with long shocks they fail really quickly. This is due to the swinging motion of the shackle combined with the torsional stress applied to the bush by the spring. Original polybushes lasted a few offroad sessions before being ovalled.

[discomikey]

i had that issue with the standard bearmach parabolics, they were really smooth and flexy but ate bushes and i twisted all 4 within 12 months, now im on RM parabolics and i know that the bushes make it stiffer as i like to loosen them off and drive up and down our drive every now and then to ensure they are settled. when loosened off the bushes can turn on the bolt and the suspension is really quite supple. but that introduces a wear point between bush and bolt. maybe poly bushes would make it more supple because the steel crush tube might be able to turn within the polymer although this would also be a wear point it might wear the bushes out quicker, it wouldnt be as bad as a composite standard type bush IMO as i have had the inner tube seperate from the rubber on my front srpings and the front end clonked when cornering. not a nice feeling.

[ToyRoverlander]

I noticed that the polybushes would wear out rapidly and the ends of the bush, and still be fairly ok in the middle section. A crossection of the bush along its length would look like an hourglass shape. I think this is due to big torsional stresses being introduced by the spring when it is flexed trying to twist the shackle sideways.

[FridgeFreezer]

Is it Johnny Joints that are a sort of hourglass-shaped bush? Might be worth a look.

I run 2-leaf fronts (TIC parabolics) and have no problems, but then my truck has a light front (V8 set well back & no winch). Or did you mean 2-leaf rears don't last on the front?

[ToyRoverlander]

No, it's the polybushes that end up hourglass shaped when viewed as a sideways crossection so to speak. In other words, in the middle of the bush the diameter is still within spec but at the ends the hole has become a lot bigger. Makes it harder to diagnose a crappy bush yet it hurts handling on road.

Normally 2leaf parabolic front springs are too soft for a series front end. Yours is a different story as it is a lot lighter as you say. 2 leaf rears would most likely work as well.

Add a big heavy winch on a standard engined series and there will not be much space left between the axle and bumpstops with parabolics. I've even a Santana with the 6cylinder diesel in it that literally had only half an inch between axle and bumpstop.

Regarding johnny joints or similar, those will not fit. However, there is a company in the US, Alcan springs, that makes leaf spring with 'orbit eyes', basically a johnny joint in the spring eye. This to stop torsional tension in the leafspring.