A little history, 71 Cuda, 340 4 Speed. I installed a new clutch and flywheel (both McLeod) earlier this summer. I also replaced the pilot bushing and throw-out bearing. Before the clutch replacement, I would get a loud screeching sound when releasing the clutch pedal only. I traced this back to the chewed up (dry) pilot bushing. I also had issues downshifting into 1st at speed. I drained the ATF and filled the transmission with Lucas 90w gear oil and have driven the car a few hundred miles since. Shifting has been very smooth, great pedal feel, no strange sounds etc.

This Saturday (so far the hottest day this summer, 90*) I took the car out and after a few miles, when coming to a stop, I was not able to downshift into 1st at speed, only grinding. Downshifting into 3 and 2 was smooth and quite. I was able to downshift into 1st while moving less than 5mph.

Do I contribute this to the heat or do I have another issue? Could be 1st gear synchro be going out? I also adjusted the clutch and have about an inch of travel.