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Suspension suggestions

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chaosego:
my bearmach  springs where intended for a d90 but sold it got the disco so decided to put them on. all four springs were the same length which i do not think is right it does look a bit odd looking at the chart and other suppliers the rears are meant to be longer dont know if this evens out once fitted ??

clbarclay:

--- Quote from: "Lyndsey731" ---Chris

The point of the cranked arms is to pull the axle back in line after a suspension lift to try and fix the issue of working angles not mess them up.

The axle rotates in differing amounts dependant on the size of the lift, this added with the fact the vehicle is now higher (causing a tighter prop connection angle) is what kills the UJ's.

I didn't bother changing them on my 200 but did on the 300 The UJ's have lasted longer and the steering is more positive. To be honest as it's been said on here time and again, lift it, see how it feels, if you don't like it then change them.

Gav
--- End quote ---


The amount of lift affects the angle of the transphere box end UJ, but rotating the diff/axle for castor correction changes the angle of the diff end UJ relative the transpher box UJ making them out of balance. In this situation a cardon prop like the disco TD5 will cure this inbalance, though its not a cheap option.

If yo want to rotate the axle to prevent the propshaft from being un balance with standard UJs then you would have to crank the arms to rotate it further forwards. The only thing that needs rotating to correct the steering geometry is the chrome balls rather than the whiole axle.

Lyndsey731:
Chris

The amount of lift effects both joints equally, the prop is basicaly a solid bar fixed at each end with a flexible joint, therefore based upon the theory of every action must have an equal and opposite reaction when you lift the vehicle the top of the front joint gets tighter as does the bottom of the back joint equally.

Additionaly when you lift you rotate the axle changing the castor angle, this as you state unbalances the joints. Castor correction arms bring them back into balance by allowing the front joint to connect at its original angle

Double cardon joints are usually used on lifted vehicles to stop the UJ's locking up on themselves in situations such as steep ramp over angles, though as you say this would do the job.

Lifting the vehicle also pulls the axle sideways which can have effects on the steering, though sometimes not really enough to notice, as always with Land Rovers it seems to depend upon the indivdual truck, an adjustable panhard rod could be needed.

Gav

clbarclay:

--- Quote from: "Lyndsey731" ---The amount of lift effects both joints equally, the prop is basicaly a solid bar fixed at each end with a flexible joint, therefore based upon the theory of every action must have an equal and opposite reaction when you lift the vehicle the top of the front joint gets tighter as does the bottom of the back joint equally.
--- End quote ---



Due to the desgin/nature of the radius arm suspension on the front of land rovers this does not happen. The relative angle of the lower (diff) UJ increases less for a given lift compared to the top (transpthere box) UJ. To make matters worse rotating the whole axle with either castor correction arms or bushes makes the angle of the lower UJ straigther, hence evan more imbalance. If your still not convinced them give me a little time and I will make a basic CAD model to explain it better than my I can with words.

Lyndsey731:
Chris

If you have the time then do me a quick sketch (or just ignore me and I'll go away soon enough)

I don't understand how you can raise one end of something that is attached at either end with flexible connections and effect one end more than the other.

For example take a pen and hold it with your thumb and finger at either end, raise one end we'll call it the transfer end, the movement at the other end (the diff) is the same.

Now try holding the diff end tighter to simulate less movement of the joint, you can't move the transfer end.

As for the arms when I said they put them back to their original angle I meant the face of the diff, obviously the UJ angle is now greater, sorry the original comment didn't read at all well, my mistake  :oops: and I completely accept what your saying there, its the difference in angles I need convincing on.

cheers

Gav

 :lol:  :lol:

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