Discovery Rust - Boot, Sills and Wings

gummy bear said:

Mr green hornet sir,u missed part 5 of water lane

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Cheers Mark!!

Ian, I will try to remember to take measurements tomorrow! All I can say for now is that my front spring plate sits dead level, nothing at all like yours, it looks horribly stressed!

The mud will wash off easily because it's all fresh paint. Ahh the joys of a rebuild!

Mr Noisy said:

Ian, I will try to remember to take measurements tomorrow! All I can say for now is that my front spring plate sits dead level, nothing at all like yours, it looks horribly stressed!

The mud will wash off easily because it's all fresh paint. Ahh the joys of a rebuild!

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Sam, I sent you on a mad goose chase. The measurement I asked for will be exactly the same as mine as they are all reletive to the moving radius arm. Lol

Basically if you're spring seat is level, ie parallel to your chassis then mine is exactly 6 degrees out. I did some more drawing in CAD and a simple two inch lift moves the spring seat 4 degrees forward.

I am therefore of the mind that the front bush position needs to move upward (the axle needs to rotate backwards) by around 40mm but need to detail the connection.

My intention is to model up some castor correction plates and have them fabricated to test. Should be fun. I can then sort out the stress at the chassis bush end. Machining in this part has already started by a mate of mine. Adjustable radius arms anyone lol

You right that the spring looks too stressed. I have a natural amount of mechanical sympathy and this is killing me lol.

I must admit Ian that as I was reading through it I was thinking that those measurement were simply measuring radius arm length! I didn't mention it though because I thought you evidently know what you're doing with this

Must be said though that I think QT arms are extended, for instance to keep the dampers vertical even though the dropping of the axle causes it to move rearward.

Have you looked at QT pictures online? Are they suitable to be used for scale drawings of the 3 and 6 degree arms?

Look at them level beauties:

Had a look at many photos but all taken at an angle so can't do that. Anyhow I would Roth approach from first principles as it is a learning exercise for me and my engineering mind lol

Correction arms are slightly longer, anything from 5 to 12mm by my reckoning.

Mr Noisy said:

Look at them level beauties:

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Show off. You could at lest sort that wonky gaiter out.

Cheers for the piccy

That steering damper is long gone anyway, RTC now fitted. It was always wonky that boot, wouldnt support itself!

Urm, don't want to stickle, but you could just buy a set of arms, or is the whole point to make some? I just don't think one could improve on the product already in production.

Cheers

Sorry, maybe that sounds a bit off. I'm just saying that the qt arms do the job just fine, I don't think theres any area that needs modifying. Rose joints and/or adjustability might just lead to more problems. Radius arms take some stick so solid/fixed would be better IMO.

Mr Noisy said:

Sorry, maybe that sounds a bit off. I'm just saying that the qt arms do the job just fine, I don't think theres any area that needs modifying. Rose joints and/or adjustability might just lead to more problems. Radius arms take some stick so solid/fixed would be better IMO.

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Absolutely agree, it was an exercise in production and adjustment that has lead me down this route.

A measurement that might interest you is my spring length at rest.

That would give an idea of just how much mine has drooped with the weight of winch, bumper, second battery, heavy lamp guards, etc etc.

I will endeavour to measure it today

A measurement that might interest you is my spring length at rest.

That would give an idea of just how much mine has drooped with the weight of winch, bumper, second battery, heavy lamp guards, etc etc.

I will endeavour to measure it today

Yeah I would interested in how much your springs have compressed.

Did some more calcs today and to get back to level spring seats, i need to raise the front bush bolt point by 15mm. assuming i pivot the axle on the rear bush bolt. amazing that thi small dim makes such a big difference.

i woulkd say the rear bush is the pivot point, but tbh im not sure. looking at pictures of the arms would let you know how they are designed.

the caster corrected arms are basically straighter than oem, so yes perhaps the rear bolts keeps its position...

will get those spring lengths

At rest, measured from spring face to face:

Drivers Side - Front 292mm, Rear 340mm.

Passengers Side - Front 308mm, Rear 357mm.

Yes, it does lean to the right, most do! I really should machine/buy some 15mm spring spacers to level it. Maybe you can make me some

Cheers.

Mr Noisy said:

At rest, measured from spring face to face:

Drivers Side - Front 292mm, Rear 340mm.

Passengers Side - Front 308mm, Rear 357mm.

Yes, it does lean to the right, most do! I really should machine/buy some 15mm spring spacers to level it. Maybe you can make me some

Cheers.

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Cheers Sam,

It never ceases to amaze me how they always seem to lean to the right. I can get a shim lathed up for you if you wish. I will talk to me colleague tomorrow and see what cabe done. It will have to be mild steel I would imagine although if you want I can make it Ali

So I have done some simple drawings of the way the radius arms move when a vehicle is lifted. Here is the simple schematic.

The white lines are the set out of the standard height discovery. The spring seat is level. Lifting the vehicle 90mm or say 3.5" (a 3" lift on mine gave me nearly 4"), you will see the difference in the spring seat angle (in Red). This angle is 6 degees.

Now to level the spring seat using the rear bush as a pivot point, The Magenta colour at the bottom, I need to lift the front bush by 18mm. This would make sense as castor correction arms are, as you said Sam, straighter than the original ones. Finally the shock base would move rearward nearly 8mm putting it back in the centre of the turret.

All looks and sounds right to me Ian. As said previously, have you tried to calc the amount the axle moves backwards as the radius arm drops? Might not be a lot, I'm not sure. You would have to balance this with the caster correction, to get the shock centred. OR is it a case of the pivot point to rear bush staying fixed and the front bush 'being adjusted' in relation axke height which keeps the axle position, or more importantly the damper position, constant.

Is it this line of thinking that denotes how a 3 link system works? Using only rear bushes for radius arm and top link takes over job of front bush effectively, but then working in a pantograph kind of arrangement. Now there's a nice project for you

Otherwise, regards the spring seat offer, very kind, thankyou

I think the lean to the right is partly due to the transmission offset to right, the drive on the propshafts rotates the chassis downwards at the right under load, the weight of the driver etc etc.

I would err on the side of caution and make spacers at 17mm.

However, here's the thing:

If you lift the spring seat away from the axle as you would with an eBay item, the weight of the vehicle is then mounted on the axle bracket. If you look carefully, the spring seat actually sits on the axle case on the rear axle. I have lifted on blocks years ago and the block bent the axle bracket.

As such, what I'd be looking for is either a ring to fit under the spring seat, or a ring to sit under the spring.

The latter would be handy as it would fit front and rear, but spring location might be a struggle.

Rear axle you could fit a ring under the seat and sit the lot direct on the axle tube as factory, the front however is supported by the axle bracket so a conventional block would be suitable. I personally think this would be better as I think spring location would be difficult otherwise as above.

So yeah. As I say, thankyou for offering. I'm not actually expecting you to make something for me, but if you are looking into it then we can either pool ideas/resources or simply run another set off and I'll exchange some money with you for them

Or I'll just do it myself, or leave it be

Cheers!

First off the spring shim idea. If you have a specific idea in mind then I'm fine to see what my guy at work can do. He is great at machining and now has started casting Ali throttle bodies too. He has made some interesting things for modified cars. At present he is building an M3 motor and a 2500 BMW motor with, get this, a turbo of a diesel train. It so big it needs a normal turbo to help spin it up to reduce the lag!

On the axle and radius arms. A three link suspension would be a great project but I haven't got the space or facilities to go wild on it, however I am considering another Discovery as a dedicated project but this is more a pipe dream at the mo.

I terms of my radius arms I can see that by pivoting the axle. Is on the rear bush I can get neutral steering and bring the axle back into position as it was originally.

What has amazed me is this. That A) such a small amount of angle change makes such a difference to the handling of a big vehicle. And B) that you have to spend nearly £250 to rectify a small dimensional change.

I can get away with a bracket welded over the existing radius arm mount. I could also just replace the axle mounts and reposition them. Either way I am really looking at alternatives to what's already available. I have had to alter the rear location cones and was really ****ed off at that. Also if I can find a local company with a bending press capable of delivering 120 tonnes pressure, the arms can be bent using my own settings.

A major consideration is that the I Beam arms aka QT are much lighter than OEM, which is a handy weight save.

Yes you could easily bolt the rear bushes, set the axle up correctly and then weld on very simple tabs to bolt the front bolt through, never though of it like that!

I will have a proper look at spring seats then, thanks for that.

And pics REQUIRED of the twin turbo setup

Nice one!