Got a 1968 mustang about 3 months ago & have been driving it a 2 to 3 times a week. It ran great yesterday, but this morning it won't go in to reverse, drive works fine. Not sure if it is a C4 or C6 transmission. Any advice will be greatly appreciated.

 

Step one will be to check the level of fluid in the trans. Do it warm with the car in park.

 

Fluid level is good; I can hear the transmission click when going in to the reverse position but it acts like it's in neutral-car rolls freely forward & backwards. When reverse worked the car would "lurch" backwards, still "lurches" forward when shifting in to drive.

 

I know that this thread is old, but do you remember the cause of the problem? I'm experiencing the exact same problem in my 68 C4.

 

The tab on the reverse band broke off, I ended up having the transmission rebuilt.