I have a SM420 Transmission in a '59 Apache. Since installing the transmission last October I have had 2 cases when the shifter handle disengages from the shifting arms inside the transmission. This occurs when shifting from 2nd going to reverse. The transmission will then "lock up" so you can not get into any gear. The roadside fix I do is take the top of the transmission off and then slide the gears back into neutral by hand and make sure the shifter arms are also in the proper position.
My theory is that the shifter handle might be worn down from use. Here are some pictures
http://www.flickr.com/photos/11159813@N00/141153523/
I included some dimensions if anyone knows what these measurments should be.
Has anyone else had similar problems with a SM420?
Thanks for any help
Adam
