re '75 K5, tailgate window crank LOCK failed when window was rolled down.
To REPLACE LOCK, window must be pulled out to access crank assembly to remove it.

Q > how to pull out the glass with the glass down (90% of the way down) and crank/lock not working ?

thanks

 

If you can see the bottom of the window, you should see two sets of bolts that hold the tracks (called 'cam' in the factory illustration/parts manual) on the bottom of the window sash These 4 bolts can be removed to disconnect the window from the regulator which should then give you access to remove the regulator & from there the crank assembly.


The two pictures above are for the power rear window option, but the parts I am talking about are shown as items #15 (bolts), #65 (cam or track), and the window assembly would be #66-#68.

The illustration above shows what goes into the factory crank handle. I do not have the part number listing for this illustration handy though.

 

thanks.
(I assume you meant to say 'access to remove window' & from there crank ***.)
have crank/lock rebuild diagrams from prior research.
best,
hb