My Indesit washer LDW7145 it makes a banging noise when it first starts spinning as if the drum is hitting the side what can it be ? .

Something is causing the drum to be way out of balance. Does it bang and make noise when it's spinning empty? Probably not. Is something stuck on the side (inside of course) of the drum, causing it to shake when spinning? If not, a spring or shock absorber (connecting drum to sides, bottom or top of machine) has broken or come loose.

Reach inside drum and see if it moves at all when you lift up and down on it or side to side and maybe makes a noise. If so you must have the drum and the rear of the outer tub replaced.

when my old machine did this it was because it was not correctly balanced and therefore the drum was banging on the side of machine.............once corrected this error disappeared xx

The two dampers that fix to the outer drum casing have plastic bushes that can fall out. Check the floor under the machine, They are easy to replace just click in place.

sounds like a balance problem may be when the drum was replaced they didn't fit the new drum in the correct spot the other thing that would cause load banging and excessive vibrations in the machine is if the shockers are worn out,
believe it our not even washing machines have shockers to dampen the movement of the drum spinning

Is it a maytag? My maytag front load washing machine had 2 long bolts with plastic braces on them, to keep the drum still during shipping. Mine would bang and shake all over. I got the book out before I finally figured it out. I had to take the back cover off and remove the bolts and plastic braces over them. They look like they' 8 inches long or so. It works great now.

Carolynn

these washers are a swine to dis-assemble and i would not recommend it unless you are experienced. on most indesit, the bearings are in a spider bolted to the outside of the tub. take the back off and see if you can localise the noise to the bearings worthwhile also taking the heater out (one nut in the middle), peer in and check no foreign object causing the noise

or the three legged spider that attaches to the drum. its made of cheap metal and one or more legs can crack or break letting the drum loose - seems like bearing but isn't! cost about £40