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you got the same tyres and pressures on each axle?

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Chrisjb330 said:

What I have noticed is that when I brake at higher speeds the steering wheel isn't pulled over. But the car turns to the left, I just correct it. So surely this means its not the front brakes?

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Unfortunately, it doesn't mean its not the front brakes, but probably less likely.
The hub geometry was changed on the D2 & similar age models to decrease the sensitivity to braking imbalance (because they were forced to improve brake performance if part of the system failed).
If they did it really well, the car should steer in a straight line with only 1 front brake working. In reality, its never quite that good, but it's good enough to reduce the effect of brake imbalance on steering effort significantly.

The bad news from that is that your problem could still be front or back.

Breaking down what's happening, you've either got :
- the brakes on 1 side still not working as well as the other side
OR
- something is moving or compressing on 1 side of the car due to braking forces to cause it to steer on its own
(even with braking power the same each side).
Eg allowing a whole axle to rotate around the centreline of the car or a hub to rotate around the steering axis.

The most likely bushes to cause the "self steering" are probably the front & rear radius arm to chassis bushes - but is hard to imagine them wearing / ageing very differently each side. It would have to be a very soft left front or right rear. You've now changed them & obviously not eliminated the problem.
With standard (softish) suspension springs, a very worn left front damper might cause that corner to dip faster than the right, causing the car to steer to the left - but its again hard to imagine 1 damper being that different to the other side (unless someone has been stupid & only changed 1 in the past).
Its easy to do a bounce check on each front corner to check if they behave very differently

Although you've obviously changed lots of components, I think you may have to go back through the brakes to re-check for anything that can cause reduced performance on the right front or rear.

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Yes but it would be more stable on rollers if you remove rear prop and drive in difflock

Or front prop either makes no difference

you can brake test a disco on brake rollers with the props on. The center diff obviously needs to not be locked. The slow speed of the brake rollers will do it no harm.

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Chrisjb330 said:

I'll have to see if I can find the diff lock switch underneath then. I didn't think they all had them?

I've heard a lot of mixed things about putting dicos on brake rollers without allowing a wheel to turn.

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No...it must be UNLOCKED.............it will be unlocked unless you locked it (if it locked it'll just climb out the rollers as soon as the start.)

You can check the foot brake as normal. You cant check the handbrake. The center diff can easilly cope with 10 seconds on a brake roller....it'll do it no harm. Youll get plenty copy n pasters thatll tell you different but thats because they have no idea how a diff works

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Do you not have brake rollers in the UK that can test permanent 4WD? we have here in Portugal and they show difference % between wheels on axle...you havn't mentioned tracking have you checked that as it can cause wheel drag which can affect braking...

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At this stage, you might want to check the condition of the radius arm bushes. When worn or if the factory-fitted were replaced with incorrect / cheap copies, the chassis might be twisting slightly upon braking, causing a resultant sideways force.

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