I've just tracked my Disco (using the peice of string method) from slightly toe out to bang in line (ish). At the same time I corrected the front tyre pressures from 40 down to 30 psi. Test drive nearly scared the pants off me! Car will suddenly wander off violently and I can just about keep it on the road. Roads around here are dreadful - if there's some deformation the car will sudding shoot off with little warning. Whole matter probably not helped by the fact that I also just refilled the front diff and the oil is pouring out from the swivle cup and all over the nearside tyre.

Q1. Re-track with a bit of toe out?

Q2. Re-inflate tyres back to 40 PSI?

Q3. Is oil seal replacement in front diff a big job? Mr haynes will probably suggest engine and gearbox out!

Q3 sound like hub seal not diff if it leaking at end of axle

Worn track rod joints?
Badly worn swivel pins?
Worn suspension arm bushes?

Probably not tracking IMHO.

If the car is wandering there could be play in your steering box I just replaced my dads as his was all over the place. His is perfect now.

Oil shouldnt be coming out the end of the axle and as thats where the wheel bolts on I would start there first.

then check the simple stuff, track rod ends etc. Steering box, thats my issue plus castor is out but hey back to you...

Your tracking shouldnt make too much diference on the disco but sounds like youre getting bump steer which is castor related and if your swivel is worn this will give you these symptons as I understand.

Hopefully someone will be along to confirm or call me a #### lol