Providing these loud toilet things are fine there is the chance that the cord running to the disposal has developed a short or a wire has become disconnected. You will need to disassemble the unit to verify all wires remain securely fastened. The last conclusion is that the motor has burned out, in which case you will need to replace the disposal unit.
Examine the washer and replace it with a new one. Also replace screws in water line repair case they are old and damaged too. The new ones you buy should be durable and of good quality.
This so impressed me, that I thought, here is the man who might fix my sink problem, and I told him about my kitchen sink. The look on his face was priceless, as he said, "Ridiculous! Sinks don't leak if they're new." He even showed me what to do. He took out a big heavy-duty screwdriver with a big flat-head blade and showed me. "This is what's probably lose." He put the blade of the screwdriver in a notch the size of a giant screw head that was right in the center of the drain basket where the plug sat in.
10) Tighten down the closet bolts making sure NOT to use too much torque. You aren't installing tires on a race car here so, take it easy Mr. Goodwrench. You just want to hold the toilet in place, not crack the porcelain base of the toilet or damage the drain flange.
As with anything, when you are not sure how to fix a plumbing issue and when you don't have the proper equipment, you should contact a professional. They can usually find out what the problem is and resolve it for you in a short period of time. They will also be able to tell you if you have any other problems and water line repair they can suggest resolutions.
And the way to know what's sufficient? Well, until the work is done an the bill paid you won't know for certain, but this is the best that can be suggested and normally works very well.
Bottom line is that it is now very easy for even a desk jockey to fix his own pipes. Go by the closet home improvement store on your way home. Pick up some of these fittings and impress the wife with talents that she did not know you had. You may even get brave and do that small plumbing project that she has been begging for. Now you can use these fittings to cut into that water line to run that new outside faucet or hookup that water filter yourself. With the push type fitting plumbing has been made easy enough for anyone to be able to do it.