Are there certain ways the crank has to be put in. Does it have to line up with something?
Here is a link to a user manual for several Invacare Homecare bed models:
http://invacare.com/doc_files/1114836G.pdf
On page 28, the manual describes how to install the Hi/Lo Crank. Once the cover on the input drive shaft is opened, the cross pins on the motor shaft will be visible. The "cross" on the end of the crank will need to be aligned with those cross pins. The crank will then need to be pushed onto the motor shaft until the internal spring inside the crank "clicks" into place.
For additional assistance, please call our customer service line at 1800-798-0325.