Knocking sound in agitator

Possible that the bearings are a suspect, if the machine seems to wobble around. Also if the load is high, does the noise go higher, if so check the suspension, check the mounting and the counter weights.
Please check this link: Wobbling machine

replace the balance springs from the bottom of the tub to the frame there weak and letting the tub rock

After taking off the front cover, look up at the top of the tub just under the lid. there should be a thick rubber strap at each corner of the machine tying in the tub to the top. These are called dampening straps. One or more may be broken. I usually replace all four if I do one.

Do you get same sound if you run through a wash cycle empty (no clothes?) using detergent? If so, then likely a basket support has come loose (check deep inside along top ring). If not, then you may be overloading washer (unless using different sized loads), or the agitator is not working like it should, and basket is torquing.

sometimes the agitator gets loose, causing the drum to sway to far all over the place.make sure its tight , remove the softener dispenser (manual nut), then tighten the metal nut that holds the agitator down

i have the same problem. the transmission/brake assembly is worn out. the stopping and starting problem... I have that too, that was a dry solder joint on the circuit board. i found it because if I pressed on the area of the panel to the left of the cycle select knob, it would shut off immediately. I soldered it back up and it's fine. Still working on fixing the transmission problem, the parts store wants 300 bucks for the part but looking at the GE website, the tranny might be under extended warranty.

remove the agitator and inspect the main shaft on the gear box.and check the belt underneath.if the shaft is bend you will need a new gearbox. hope this helps.

I believe you must have one of the bottom of the line cheapo washers, as I do--the one with the plastic, rather than steel wash tub and basket? These are pretty poor machines. They cut corners drastically in every part of the design. I've replaced the aluminum hub that supports the spin basket ( the hub is bare aluminum and corrodes within about 5 years use from the highly alkaline detergent, then it fractures under mechanical stress. Then the motor burned out. I was able to get a nearly new motor on ebay for $90 incl. shipping. (BTW, if you need appliance parts try GOOD Appliance on ebay for new and salvaged parts--they're excellent! 100% feedback rating) However, I now have the same problem--a fairly loud knocking noise during the agitation phases of the cycle. This is cause by a really crappy transmission design that does not wear well. My advice is just ignore it as long as it works and isn't leaking oil and the tub seal is still good. If it does finally go to pieces get one on ebay--that is if you feel up to doing the job yourself since a repair person would charge more than it's worth to install it. I believe new ones can be had on ebay for about $80, some are sold with seal kits. Bottom line is--if you want a machine that will last you for 15-20 years--don't buy a cheapo model. The front loaders are better as they use far less hot water (energy and water savings) but a good one is going to be anywhere from about $800 to $1600.

The problem is 2 fold. The "knocking" noise is indicative of brake rub. The fix is to replace the rotor & stator. The reason that your clothing are coming out wet is because the brake is dragging along a polished stator when in spin and cannot get up to its proper speed as a result. The 2nd item that should be replaced is the thrust bearing assy. This is what enables the transmission to transition from agitation to spin... Hope this helps... Bill