Toploading GE Washer sounds like a jet engine during takeoff

Manufactured by: GE Appliances

Model: GTW500ASN0WS

Date on device: 2019 August

I got a set of laundry machines from a friend who was moving and no longer needed them. They were effectively new when I got them, and I've done my best to take care while using them.

The washer has recently taken to sounding like a jet engine during takeoff, so I went through various troubleshooting steps, which I'll detail below. I have found myself stuck after a certain point and feel the need to talk it through with folks who are more experienced.

There was a brief period where it seemed like clothes weren't getting rinsed properly, but that issue subsided in the midst of troubleshooting. My main issue is the sound, since I know that it can indicate an issue which shouldn't be ignored due to risk of damage.

In case it helps: the water here is incredibly hard, so I ran an empty load with vinegar to clean out any scaling that might have built up prior to attempting diagnosing the issue.

After getting error codes while in diagnostic mode, I followed the steps from the manual:

Error code 1: 3

-physically check the washer for anything preventing motor movement

-measure resistance on the motor between the brown and white wires and the brown and yellow wires

verify hall sensor is connected to the main harness.

-Put washer in service mode and run test 14 (Spin). if hall sensor is bad or disconnected, the basket will start to spin normally and then stop spinning after approximately 5 seconds.

^ This did NOT happen

Ensure hall sensor is properly connected and positioned on the motor. If basket spins for approximately 15 seconds, the hall sensor is most likely NOT the cause

^This did happen

-TCO should reset in approximately 45 minutes. If TCO is tripped, make sure motor moves freely and that nothing is jamming it. Replace motor if it does not.

^ Everything appeared fine, ran like normal

Error code 2: 1

lock monitor

-check lid lock using service mode spin test 14

-check lid lock harness connectors both at the main board and at the lid lock assembly

-measure resistance at motor between the white and green/yellow and green/yellow. ensure that it is an open circuit

^ Everything appeared fine, so I unplugged the machine, drained the water, removed the hoses, and moved the unit out of the laundry closet to examine it further.

There was still some minor shaking during the above tests, which was resolved after I checked the plastic feet and made sure they were all matching lengths, which they hadn't been. (Unknown for how long this was the case, probably since day one unless one somehow got unscrewed over time.)

After that I attempted the following:

• checked the hoses to make sure there wasn't any issue with them
• checked washer underside, cleaned off the dust.
• checked the wires and parts around the motor, nothing seemed amiss
• manually spun the tub to check for any issues with the belts, which were fine
• removed the case for the controls and backsplash, checked the motherboard (which was fine)
• removed and examined the various cables attached to the motherboard (they also seemed fine)
• removed the top panel and lid
• checked the gaskets
• checked and cleaned the pressure sensor
• removed the tub cover and cleaned it before returning it
• checked the outside of the drum over
• checked the suspension shocks. They seem fine, but there is some red grease around the socket lock where the suspension rod hooks onto the cabinet
• examined pump drain, which was fine

I was unable to completely remove the belt protector, and thus couldn't fully access the motor, but what I could see/test was in working order.

Since I couldn't proceed further...

• I reattached everything and put it back together
• ran an empty load with citric acid to clean off any limescale since the water around here is so hard
• wiped down the insides to make sure there was no residue
• ran some normal laundry

Initially I went in thinking that I'd need to replace the belt, but it seemed fine when I tested it manually. My suspicions now point towards the suspension shocks, though they showed proper resistance when I pressed on the drum and rotated it with my hand.

Before I tear this thing apart again or buy replacement parts, is there anything that I should do? Am I missing some vital step?

Thanks much