1yakini

Had a rebuilt t56 put in my cts-v due to a bad input shaft. I had the shop install a ralco short shifter, along with new motor mounts, trans mount and the usual rear diff replacement bushings.

Broke it in for a good 500 miles driving it nice then began to drive a little harder. I found that I had a 4th gear synchro grind but... only when the trans was warm (130) and only when there was a high rpm change ie 2-4 shift above 4k/ 6-4 downshift at cruising speed/ or 3-4 shift near redline. This occurs even when granny shifting under these conditions. My speed shop said the rebuild was off and the warranty company is building another that will go in next week.

I have read over and over that these shifters can possibly cause the synchro to go prematurely, doesn't really make sense when considering it is simply leverage but figured I would ask. Also with such low miles on the trans how could the synchro been shot already even if I possibly made a bad shift or something? Also why the hell it only does it once the temp is up on the trans?

Any ideas? I don't want to have another one go and they start blaming me....