Gents I have strange braking issue on 4.2 s/c normal town driving all fine when braking from speed and quite hard there is a loud drone and occasional shudder through the steering wheel so thought warped disc but there is no feel of it on light braking has brembo discs and pads discs new pads half worn so thinking bushes ?? Have recently replaced front lower arms any ideas chaps

could be other bushes or ball joints causing the judder so check the upper arm ball joint, and the joints on the trac rod ends, but its unlikely to be causing the drone, It is always best practice to replace the pads when you replace the discs as they will have bedded to the old discs and will need bedding into the new ones, they are quite reasonable now anyway.

it may be the pads vibrating in the caliper so have them out and a good coat of ceramic slip on them may help. As for other ideas judder, check to see if you have a split in any of the rubbers close to the discs, either on the ball joints or on the driveshafts, they can when they split deposit grease onto the disc which will reduce braking force and cause both the drone and the ruder you describe, had exactly that on the 3.6 , new gaiter needed unless it has just come of on the end, and if it needs a new gaiter the driveshaft will have to come out of the hub assembly to slide it over. There is nothing that can't be fixed with a hammer😜😜
FFRR 4.4 SDV8 Autobiography Santorini Black.
Fiat 500x 1.4 multiair Lounge 2015
2010 LR D4 Commercial 2.7 TDV6

I put new discs and pads on about 10k miles ago I have new discs and pads in the garage might try new pads as a start
Ta for the pointers