I replaced the old regulators in my 87 IROC. The new ones are slightly different, I believe from a 92 up. However, they did fit with one slight problem. The window doesn't go all the way down. The gear bottoms out with about 3 inches left. There doesn't appear to be any adjustment, they fit how they fit. Any ideas?

Steve

 

Pics? Sounds like its the wrong regulator...maybe a 4th gen unit??

 

Yep, I think they are 4th gen. They are actually swapped. Left for on right side an vice versa. However, any search for third gen regulators shows this model as replacement on multiple supplier sites

Window bottomed out


New regulator

 

I recall that there were none made for third gens...but found for fourth..maybe they FIT but don;t work properly?