cast iron t-10

[tomhawk]

Is there any difference in my 66 Shelby cast iron trans. and regular production transmissions?  As far as gears, input shafts? I have owned a few aluminum case trans. and sometimes they would pop out of 2nd gear. Is that common?

[gt350hr]

  Production GT350 T-10s were different than "production" Mustangs . It was "close" to the K code trans but had different 2nd and third gear ratios. To do this the GT350 trans used a different input , cluster, third and second gears. The other parts were the same except the '65 , 66 Crryovers and early '66s that had a cast aluminum case and tail housing or combination of iron and aluminum.Later (maybe around 1,000) units were all cast iron cases. In road racing , the cast aluminum cases often cracked and iron replacements were often substituted.

[S7MS427]

I have owned a few aluminum case trans. and sometimes they would pop out of 2nd gear. Is that common?

My personal experience with a T-10 is that it would pop out of 2nd gear when letting off the gas.  I've been told that this was due to excessive end play on the main shaft.  Bad things happened one night when in my Mustang I tried to hold it in gear to prevent it from popping out of gear.  The mainshaft twisted into three pieces and took the tail housing with it.  I became a Top Loader convert after that.  Ah, the lessons we learn when we are young...

[gt350hr]

   Popping out of gear is a combination of small problems that have been cured (90% of the time) with new design "sliders" or synchro assemblies. I have done about a hundred that are trouble free including several vintage race cars.
   Randy