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?
Personally I do not think you have an issue at all here.. Granted I am sure your tranny is older and worn some, but this was the norm back when these were fairly new...
Why would you want a first gear downshift for anything but coming to a stop at a sign or redlight to be prepared ( in first gear) for proceeding after stopping????
Again, I don't remember 4 speeds being really friendly about going into first at much speed....
Not the way I remember them. There was many times I'd be rolling along in 4rth with my 833. Simutaniously floor the clutch, floor the throttle as Im jammed the shifter from 4rth to 1st for a roll race.
Anyways there is 2 definate ways to engage a gear. One is with light pressure on the shifter. This gives the synchronizer time to slowly spin the speed gear to the same rpm, once its matched it easily slides in. Like stepping lightly on the brakes.
Next method is a strong forceful engagement, like described above. This gives the synchronizer less time to match speed but since there is so much pressure on the it will quicky match speed and go in. Again, like braking hard.
Either method will not grind the gears in a proper functioning transmission.
