2" lift. Dumb question number 3

[Bob696]

OK ... got new boots on now and she looks a lot better.

BUT

I am reading different things about what else to do. Some people are saying with a 2" lift you dont need to do anything else except perhaps the brake lines need extending (the front right needs it but others have a lot of play, but I will do them all anyway). Other people are talking about changing the radus arms and some angle or other (whoosh.... what was that that skimmed the top of my head).

So then, what else should I be looking at changing ?????

[datalas]

OK, I'll try to start in the simple ;)

The reason for the brake lines being replaced are simply because your springs (front and rear) are making your axles naturally sit further away from the chassis,  when you are the full extent of your articulation you don't want the brake lines to be the only thing holding the axle up, because it would break and that would be a *bad* thing.

The reasoning for castor correction is perhaps a little more peculiar.

by lifting the suspension you are changing the angle at which the front axle points, i.e. it is pointing slightly downwards, this means that when you turn you are not only turning the direction which the wheels are pointing, but to some degree you are actually "tucking" the wheels under the vehicle.  This means (amongst other things) that the self correcting of the steering is reduced, making its on-road handling a little vauge.

Castor correction (via the radius arms) bend the axle back to the flat,  this will sadly move the diff with it, thus increasing the angle and the strain on your propshafts.  However this usually only exhibits itself as a strain on the front one since the rear is longer.

at a 2" lift, the castor will be out by around 3 degrees.

[Bob696]

cheers datalas

So I should look at changing the radus arms then but will the standard ones 'do' in the mean time? Also with the extra strain on the propshaft (is this extra strain you mentioned with the correct castor angle or the wrong castor angle?) do I need a longer propshaft?

[datalas]

you don't need a "longer" one per sae, more a double decarbon (I think that's the term) one, which is basically a prop with a really fancy looking UJ at one end.

The TD5 Disco 2's had one by default (I beleive, but don't quote me on that) or alternatively you can buy one from a number of other retailers.

Note that you don't *need* to do this, but you will most likely shorten the life span of your UJs and might suffer from a little vibration, clicking, clunking or other such.

And, yes, you *can* run without castor corrected radius arms for a period of time, but personally I'd prefer not to.

Incidently, you can also get hold of castor corrected swivels, which are the same sort of thing but with the bend in a different place.  However I don't have much in the way of experience with them.

Btw, read messages in the Bar about "a warning" (I think you have been doing) and consider contacting myself (and/or) Bulli directly for our more strongly formed opinions on suppliers ;)

[Bob696]

I wasnt thinking of going with scorpion for the raduis arms as they have always struck me as being very pricy.

I was thinking of ringing mill services to see what they can do. Failing that I like the look of the QT radius arms. I have no idea what Tims favourit devon 4x4 are like as I have never used them.

If you get chance at Abingdon I would really like you to take a look at what I have done just to make sure it is safe(ish). I would say there would be a beer in it for you but I dont think you drink  :roll:

[datalas]

Tigger and Piglet are both on QT radius arms, and I have a set sat in Tim's garage waiting for them to be bolted to my 90 when I get it built.

I'll be at Abingdon, so will muddy, so you should be able to get a profesional opinion (and my opinion too)

[littlepow]

What the legality of running with uncorrected castor anglea, in terms of insurance liability?

As the steering is effected can insurance companies refuse to pay if involved in an accident. Obviously this is taking into account that they have knowledge of the changes to suspension.

[datalas]

Theoretically, since you have informed them of the modifications you should be covered.

However, the onus would be on you to get the insurance company to certify that your vehicle is covered, with the declared modifications.  If they have any questions regarding the technical expertise of the modifications then they should be directed to you so that you can provide satisfaction..

Although, you probably need to talk to your insurance company.

[Range Rover Blues]

Castor correction (via the radius arms) bend the axle back to the flat,  this will sadly move the diff with it, thus increasing the angle and the strain on your propshafts.  However this usually only exhibits itself as a strain on the front one since the rear is longer.

Also the rear axle is supported by a different type of suspension and moves nearly parallel in all but extreme lifts, so the angle in the 2 UJs increase roughly the same amount.  That said I was looking at a motor with a 5" lift this afternoon and the rear diff was slightly too nose-up for the prop to be 'happy'.

The front prop on any coiler is unusaul in that a standard car does not have the gearbox flange and axle flange parallel, although the 2 ujs drive through roughly 3 degrees each thus balancing one another.  When you lift the car only the gearbox UJ increases in angle, leading to the imbalance that causes the pulsing.  Castor correcting arms effectively straighten out the axle UJ, making things worse, hence the Cardan jointed or TD5 prop.

Incidentally I was looking into getting castor corrected swivels from Tomcat motorsprot but they are 6 degree corrected ie a 4"lift and too much castor is as bad than not enough, possibly worse.

I think it's time for an in-depth article on lifting coilers.