Hummer H1 knocking Noise

[spacom]

The other week I was traveling down the road and suddenly I heard a very loud crack it sounded like a spring that broke under the drivers side, and I seemed to notice more rocking when I braked.
I took it to my workshop to investigate but only found play in the ball joints,
so I replaced all the front ball joints But still noticed more rocking than usual
and when I put in drive 2 and accelerate and let gas off I notice a soft nock like play in the transmission is this normal !
I have had every wheel off the ground and found each to have the same play
checked all shockers and drive shafts seem to be OK
what could it be.

[NoMoGMPG]

Not alot to go on, but here are a few things to check:

Brake caliper brackets
Springs
Axle shafts
Axle shaft bolts, both at the diff and the one retaining the axle in the geared hubs.
u-joints
center support bearing on the front driveshaft
shocks (seen a few break at the top)

[spacom]

I also seem to get a front brake grinding noise from the front when hot but seems to go when I brake !.

[NoMoGMPG]

I also seem to get a front brake grinding noise from the front when hot but seems to go when I brake !.

You need to check your caliper bracket mounting bracket and your axle bolts. It sounds like the bolts have backed out. Major brake damage can result.

[spacom]

I have checked the calipers I thought it must of been the cheap pads I bought at the auto store so I put some better ones in carbon metallic,
took for run and when I came back to my garage I heard what was like a brake shudder noise,
and I also have more rocking even with the slightest braking this was since I head the loud crack noise,
But is it normal to have noises when in low gear when I decelerate like transmission play but I never noticed this befor as I always have it in drive
gear.

[Yetti]

are you getting side to side rocking? if so I would check your swaybars. you could have snapped one and now its flopping around in its mounts