Adjustable control arms , erm Why ?

[makeitfit]

I'm in the process of fitting Y61 axles to my Y60. I've seen mention of adjustable control arms ?
Can someone explain in idiot terms please the advantages of them?
I've got a SWB wagon, +2" suspension lift, +2" body lift, running 35s and used in anger lots :tongue:

[Ben-e-boy]

generally to correct you pinion angle after a lift. Not needed for a 2 inch lift. But, they are usually heavy duty so that is a winner

[happygu]

Makefit,

The purpose of Adjustable Control arms is to put all the driveline components back as close to possible to factory specifications.

There is no need with a 2" Lift, as the diffs are still within tolerances to have a good ride.

When you go higher, it plays around with the geometry, as the arms are still fixed to the same point, but have now rotated down a lot further.
For instance, it will rotate the rear diff, so that the springs are not mated at each end to a flat surface ( top and bottom seat ), as the lower seat on the diff is now at an angle to the top. When the springs are under compression, they tend to bow out towards the rear of the car in the middle, instead of compressing in a straight line down from top to bottom, the spring is now being forced backward and well as being compressed.

An adjustable lower control arm can lengthen the bottom arm, or an adjustable upper can shorten the top arm, to make the spring seats sit flatter to each other.

Mic

[makeitfit]

Nice one guys, that makes sense ;) So in the interests of keeping the spring seats true and getting a bit more room for the 35s to flex. I could fit adjustable upper control arms and so extend them a little .

[happygu]

Makefit,

If you want more room for Tyres, generally, you will need longer lower control arms, as the pivot point at the rear is in front of the wheels, when you fit larger springs, it will rotate down on the pivot point, and pull the tyres closer to the front of the car.

What you need to do, is to lift the rear of the spring seat or drop the front......Longer Lower Control Arms will do this, and you can get them in fixed lengths or adjustable lengths, and Shorter Upper Control Arms will do this too.

If you are planning 2" lift only, I have never changed control arms - the tyres will fit fine in the rear.
It is the fronts which give you grief, and you could need to fit spacers on the front radius arms to move the front tyres forward to stop them rubbing on the flares / mudflaps when trying to turn to full lock.

Mic

[makeitfit]

Ah I got the UK version, it's the wrong way round lol
Cheers for that ok I'll make longer bottom arms then, easy enough. I've already done +2 coils and run 35s, but more clearance is always good ;)
I binned the front flaps ages ago lol What sort of size spacers do you reckon? Also will these spacers help correct castor angle too ?

[Clunk]

15 mm will generally do the trick. Don't think they'll help with castor correction though but happy to be wrong as always.

Don't stroke it, TAP it!!!!.....

[threedogs]

You can cut guards to allow for bigger tyres if done right looks factory.
Easy on GQs as the front flares are stepped

[makeitfit]

15mm further forward also gives 15mm better approach angle , I like ;)
Is the thread at the end of the arm long enough to allow 15 mm spacer by the way ?

[Ben-e-boy]

Ah I got the UK version, it's the wrong way round lol
Cheers for that ok I'll make longer bottom arms then, easy enough. I've already done +2 coils and run 35s, but more clearance is always good ;)
I binned the front flaps ages ago lol What sort of size spacers do you reckon? Also will these spacers help correct castor angle too ?

I personally would make fixed length lower arms and make them stronger as they are suseptible to damage. You only have a 2 inch suspension lift. Geometricly its still going to be within spec.
With the front I would not be putting in spacers as you may have clearence issues on the front left with your drag link, panhard and diff.
Guard cutting is the best for clearence with a small lift and big tyres

[Clunk]

15mm further forward also gives 15mm better approach angle , I like ;)
Is the thread at the end of the arm long enough to allow 15 mm spacer by the way ?

Sorry mate I was thinking of the 15mm spacers for the front radius arms...... Just woke up, still sleepy.

Don't stroke it, TAP it!!!!.....