Washer spins, agitates only counterclockwise

[Jani]

Kitchenaid washer fills with water, agitates only clockwise making horribly loud knocking noises, spins just fine.  It goes through all the cycles, just makes the loud rhythmic knocking sounds while agitating.   We took the agitator off, filled the tub with a small load size of water and watched the metal post (with a flashlight as we cracked the lid just enough to see inside- agitation stops with the lid upright)  The metal post went back and forth as we suppose it is supposed to.  There was no loud knocking sound.  We took apart the agitator and looked at the "dogs" whose ends were rounded rather than have little teeth that I thought should fit into the notches.  First question, do we need to get an agitator repair kit to replace the dogs?  We put the agitator back together again and put it back into the tub, ran a small load of water, when it began agitating the loud knocking sound returned.   We did all this today.

Last week a repairman told us we needed a new transmission, clutch, and drive coupler, he said the repair would cost $450, not including the $140 for the service call.  The kitchen aide manufacturer recommended him and made the appointment for us.  I feel quite taken advantage of.  We paid him the $140 but we plan to try to repair it ourselves.  I don't think it is the transmission, we see no oil sprayed anywhere nor is there oil in the washwater.  The machine does all it's supposed to do except agitate back and forth in a quiet manner.  It only agitates "forth"  which causes the clothes to become hopelessly twisted around the agitator.  So I resort to filling the tub, agitating for 30 seconds, I turn off the machine to let the clothes soak, swish them by hand, spin, rinse and spin twice with little agitation and call the clothes: clean.
Are we on the right track with repairing this machine?  Agitation repair kit and perhaps a new drive motor to transmission coupling.  Clutch?  Any advice is greatly appreciated.  I wish I had kept my old Maytag that served us well for 30 years.  

Model KAWS850LQ2

[JWWebster]

Some repair photos

[Jani]

Wow, thanks!  The videos are going to be sooo helpful tomorrow when we tackle
this job.  We plan to start with the agitator "dogs" and if that doesn't work we
will move on to the coupler.  I figure we have nothing to lose by trying to fix it ourselves. 
The "dogs" have no teeth, they are worn down.  I hope this easy-to-do project will fix the washer.  I'll let you know!   

[AJ]

You may also find this topic helpful.

Whirlpool washer not agitating

Here is a guide I also wrote to help check and replace the motor coupler.

http://appliancejunk.com/motorcoupler.pdf

[jumptrout51]

It is quite possible the agitator dogs are your only problem.

[JWWebster]