I need help adjusting the gearshift linkage on my 88 4-speed GL. 

I think the PO had problems with it, because he added a gear shift lever extension that gives a lot more leverage. I have had issues with it from the start (which was a year ago) - in particular, getting it into first and reverse, and grinding between 3rd and 4th. I've had all, or almost all the replaceable bushings, etc replaced, and finally I had a rebuilt trans installed, due to the above issue with the 3rd/4th syncromesh. 

Yesterday on the way home from the shop I could not get it to shift into first without pushing down as if I was going into reverse - not a new problem but worse than before. I crawled under it and tried slightly rotating the linkage, where the splined center portion goes into the clamp on the rear portion. 

Now it goes into first just fine but... no reverse.

Steve, in Chicago with ’88 tintop Vanaru.