How do you remove the nut under the agitator? Ours is leaking gear oil from bearing under agitator. Have the agitator off. GE WBSR3140DW

That is a very old GE model. There may be a screw under the agitator cap which needs to be pried off. Even with the screw removed the agitator usually rusts or bonds to the transmission top. GE had a special pulling tool that was a metal ring that fit over the agitator with 3 set screws in it that you had to screw into the outer plastic of the agitator. A gear puller was then needed to pull the agitator off. Don't know if its worth it considering the age of the machine.

I would try to get clothes out, even if destroyed first. Otherwise,
there is a plastic cover cap on the top of the agitator. remove
by unscrewing or prying off. Hold down nut is exposed and remove
carefully, gently and with a ballanced pry up from underneath to raise agitator.

the most likely cause if the oil looks like motor oil that you put in your car but only thicker,is that it is leaking from the transmission which is very common in ge washers the oil is in the transmission to lube the gears which make the machine agitate
to be sure you could remove the front panel and would see alot of oil in the base frame
to remove the panel place a screwdriver between the panel and top and feel around and find 2 clips (one on each side) press on those clips while pulling the panel out

the tube seal has failed most likey due to a bad tub bearing, u will need to remove the tub to replace both, a very involved job

there are springs under the machine that attatch to the tub in 3 to 4 places if one of these springs break it will cause the tub to bang.

Remove the agitator cone. There will likely be a removable plastic piece with an O-ring. Oil could be leaking out of the O-ring into the washer, and water could be leaking into the bearings. If there is damage to the O-ring replace it, or if there is a bunch of schmag that is compromising the seal, clean it out, and re-install everything. This solved the problem in my washer; hopefully it works for you.

GE style washer Common problems: - greeseOil on the clothes or floor. In most cases a new transmission will be required. You can rebuild the Trans for oil on the floor, but I find it best just to replace the transmission with a rebuilt one = less problems and faster repair. I have a parts breakdown of the old style transmission here. How to access the washer information.
Change transmission in GE washer-Take transmission out for repairs. - Unplug washer. Remove agitator from washer by pulling straight up on it, some agitators have a bolt under the cap, remove cap and look for a bolt first. Remove the agitator bearing from transmission hub. Get top up by pressing on 2 clips located about 6 in in from side between top and cabinet. Putty knife or flat blade screwdriver works well here. Take the filter flow tube off. Lift top. Remove three bolts holding basket to hub, and use a 12 POINT 1/2" socket to remove the bolts. Lift basket out of washer. Remove the two clamps holding the black boot to the tub and to the transmission. There are six bolts holding the transmission in the washer. Remove the bolts and lift transmission out of the machine.
To replace bottom seal - Turn trans. upside down in a bucket, put in vice, etc. Remove the nut holding the drive pulley on. Take drive pulley off. You can now pry the oil seal out of the trans. bottom and replace. If you wish to put the proper amount of oil in the trans. you will need to remove the bottom cover. Unless you have lost a great deal of oil, I would bypass this. I would estimate the oil loss and put in a lesser amount through the opening where you will be putting the new seal. When replacing the pulley, do not turn the nut holding pulley on. Hold nut stationary and turn pulley in the direction that nut will tighten. This will keep you from separating the hub, torque spring, and drive collar in the transmission. If you see evidence of water in the transmission, my recommendation would be to purchase a rebuilt transmission and repair in that manner. You may wish to do this regardless of the condition of the trans. You will receive a one year warranty with the rebuilt trans. I have a parts breakdown here for the transmission if you need it.
Usually you have to only add a little oil to replace what was lost...not much...really!!
The oil used is a Non-detergent, Gear oil approximately 90 weight. The main pulley seal is WH8X281 and foam nut seal is part # WH2X671.

Simply pull up on it very hard.
It will come off.

theres no nut and bolt,,only a cam or bell ..you have to roch agitator back and forth,,until it losens,,and pull up reall hard..or put your belt under agitator and yank up..onthejob

1. Remove the acorn nut, hex nut, and washer that hold the "planetary" agitator section on the transmission shaft.
2. Remove the trim ring (if any) around the same.
3. The agitator section should now be able to be worked free.
4. Remove the retainer clip on the top of the agitator shaft. (Some models have a pair of hex nuts here; if so, remove those.)
5. Pry the gear up and off the shaft. Remove the square key from the shaft keyway at the same time.
6. Tap gently on the top of the agitator shaft to drive it out from the bearings and grease seal.
7. Recommend removing and replacing the top bearing at this time; it's inexpensive to replace, if you're in this deep.
8. Use a suitable diameter piece of round steel stock to drive out the lower bearing and oil seal. I don't recommend using the agitator shaft.
9. Clean thoroughly, insert a new bottom bearing and oil seal, drive in place with a rubber mallet.
10. Replace agitator shaft through oil seal and bearing, tap gently into place.
11. Fill cavity with approved lubricant. I use USP-grade mineral oil, as it is food-safe and provides satisfactory lubricity.
11. Install top bearing, tap gently into place.
12. Reverse steps 5-1 to reassemble.