The black plastic screw on bottom of the pitcher is stuck on the base. We can't seem to get it off. Have any hints

Just go to your search engine (I use Google Canary) and type in "replacement pitcher and manufacturer, model name and/or model number". If you look on the base of the unit it should have the model name and number for you, usually on the bottom.

You don't say what is making them stick together or what you've tried to do. Gentle heat is usually helpful and sometimes hot water can dissolve the "glue" that's causing the problem. If the pitcher is used for sweetened drinks or if it is a small pitcher used for milk or cream, the hot water can do the trick.

-I don't think they carry any replacement parts for Ninja Blender.
-Possibly not the spline plastic.
-Inside on top of the motor there is a planetary gear there. Possibly worn out or lose screws as well that not hold it in place to mesh together.
-But before you can reach to these parts you have to take the bottom cover off, remove the plastic spindle. IT's very tight.

Good luck

Mai

Try some grease on it, or very hot water.

You will likely need to replace the beaker anyway, the drive which is now melted to the motor coupling is only supplied as part of the beaker/blade assembly. You will also need a motor coupling.

This can be coming from discoloration and/or food acting on the rubber gasket. Be sure to take the pitcher apart, removing, the screw on base cap, the blade mechanism,and the gasket to clean your blender after each use. Acids and liquids can act on the rubber causing a discoloration and this will seep into your pitcher. This should take care of your problem. If it does, please come back to Fixya and rate my solution!

slide it over the blade ,, so that it sits between the blade base and the pitcher bottom

the older glass jar blenders were sold as a complete ***'y too.
no separate parts were available. i'm sure the stainless jars are sold in the same way...complete.

This just happened to me too, and I think I just fixed it.  First you have to get a replacement part called the "blender coupling" (I got mine online from Goodmans for $3.99).  I also replaced the square drive and slinger (two parts come together for $2.99)-that's the little part that sticks up and attaches to the pitcher.
Unscrew the bottom four screws of the base where the rubber feet are.  Remove the rubber skirt to reveal four screws that hold the motor in.  They are way in there so you'll need a long screw driver.  Remove the motor and unscrew the old coupling.  Mine had not been replaced since my grandmother bought this blender who knows when, so the coupling was really stuck.  I did not have a tool narrow enough to get a good grip to apply enough torque to remove the coupling so I had to try a few other tricks.  If your blender is the same, remove the bottom nut, fan blade and two washers.  This gave enough of a rod to grip to get the old coupling off.  (I also had to use some WD40, and heat and cool the coupling a few times to break the old seal).
Good luck!  Hope that helps!

Hello Guest - Would you have the number? I can't find it anywhere...thanks!