Threaded impellers include below items
3020-0801 Sherwood 17000A ( threaded/thru-key design)
3020-0912 Sherwood 18000K
3020-1201 Sherwood 22000K
3020-0915 Sherwood 26000K
3020-0802 Sherwood 27000K
3020-0914 Sherwood 29000K
3020-1202 Sherwood 30000K

Removal steps:
1.Reomove the cover
2.Insert the impeller puller into the threaded insert.
3.Screw the puller against the shaft,lifting the impeller out of the housing or until loose.
4.Twist and pull the impeller out of the pump.

Installation steps:
1.Apply a non-petroleum based lubricant to impeller.(It's very importan,or impellers easy demagedt!!!)
2.Install the impeller with a twisting motion onto the shaft.
3.Use impeller puller tool to push impeller into pump by loosening and lowering nut until tightens against impeller insert,then turning for installation.
4.Use a small amount of non-petroleum based lubricant to help hold the O-ring in place while replacing the cover.
5.For the 3020-0801(Sherwood 17000K) align key and keyway by rotating the impeller.

Caution:Replace impeller key and place the the ruber cap cover the key opening to prevent possible damage to the cover.