727 Shifter Stuck

[70 Challenger Lover]

Any thoughts on why the shifter in my 727 suddenly won't move past reverse? It was fine up until today. Definitely not anything exterior holding it up from what I can tell. I even disconnected the rod to the lever itself and when I manually shift it under the car, it simply won't move past reverse.

[chargerdon]

Probably the "rooster comb" in the valve body is broken or jammed.   You will probably have to drop the transmission pan and take out the valve body.   

[73_Cuda_4_Me]

Maybe the NSS/Backup light switch broke?

[Chryco Psycho]

often the detent rod in the shifter i not being depressed far enough , the 70 has more trouble with this , remove the shifter handle & see if you can move the shift depressing the rod itself in the shift if so the shift handle is worn or damaged

[chargerdon]

I even disconnected the rod to the lever itself and when I manually shift it under the car, it simply won't move past reverse.

I would take out the NSS switch first and try again...   then ...proceed to the valve body rooster comb...   

[70 Challenger Lover]

It wasn't the neutral safety switch. Removed the pan but found nothing wrong yet it still wouldn't move past reverse. Removed the valve body and still found no issue but once on the bench, the shifter worked perfectly. My theory is the park rod slipped out of its notch and got bound up. The park pawl seems to work perfectly and the C clip looks like it's oriented correctly.

[loche451]

I had sticking problems with my 727 slapstick ...turned out that under the floor console my linkages had a bunch of carpet and junk inbetween the springs and rods for the slapstick. Note- this is IN the vehicle. 

Its a quick check to see if something similar is happening with yours

[70 Challenger Lover]

The problem was there with the trans disconnected from the car. I removed the valve body and reinstalled it. Problem disappeared. I think it was related to the park rod going into the tail housing.