Low Gear Lock out

[Lancer]

Our Avanti (1983) has the four speed GM transmission and it would seem that it can be manually put from drive (4th gear) into low (1st gear) at speeds that certainly could be harmful to some element of the drive train. My experience is that at about 25 mph the rear wheels lockup in a effort to slow the car which tells me that is much too low a gear to be in at that speed.  I thought all transmissions of the automatic persuasion had built in lock out functions to keep them from being accidently shifted into a lower gear than is safe.  Should I be headed for the transmission shop, or is this normal?

[Ray K.]

I think the lower gear "lock-out" is a more recent phenomenon. As a novice driver back in the '60s, I was shifting a 3-speed GM automatic manually while drag-racing. I accidentally slipped from high gear through neutral and into reverse at 60 mph. The rear wheels locked up. I expected the tranny to come through the floor, but to my surprise nothing happened. I put it back into high gear and drove home, with no ill effects. Your transmission is probably OK.

[dynolou2]

When you pull down to the first gear position , when it applies depends on governor weights and rear end gear ratio. It only does what you selected it to do. Same thing when you manually up shift, except that you are on the throttle up to the redline or less.  Lou Cote