Tom from SWISCO responded:
August 8, 2013
Hmm... do you think you have the 39-089 and 39-090 instead? The link arm for these is also 5" but the gear arm is different and may compensate for that 1/2".
You see, the 39-089 and 39-090 have a gear arm that's shaped more like a Z, while the 39-187 and 39-188 has a gear arm shaped more like a W. The difference is subtle, and hard to spot at first, but if you look closely you can see what I mean. |