1999 suburban tranny probs

Likely the tranny needs a rebuild. Did it fail over time or simply fail immediately? I can't remember which solenoid reverse is on, but a sudden failure would more likely point to a solenoid. Gradual failure to the point of no reverse is likely clutches. That would be a rebuild.

Reverse is not on any solenoid in Hydramatic transmissions. One forward and reverse are always obtained hydraulically. 4L65E, the lighter trans, uses 2 clutches for reverse (reverse input and low/reverse), 4L80E uses 1 clutch (2nd) and 1 band (reverse).

Butter it, it's toast.

Guess that explains why I could not remember which solenoid it was on. Automatics are almost a black box for me - not completely so, but I never claim any detailed famiarity of them. This is the one area of my vehicles where I turn to a friend who does nothing all day long but work on trannys, and let him be the hero, anytime I have a tranny problem.

You could pull the codes and see what the computer thinks is failing.

The computer will have no idea that reverse is gone, it doesn't care. The trans has to come out. There's either a massive fluid loss, like a cut lip seal or cracked piston, or burnt clutches. There's nothing you can do with the trans in the vehicle.

Thanks for all the replies. I took it in today and yup ,it's toast.