How do I know if a Torque converter is bad ?

Hi All

I have a what I think would be simple question ..but I am not sure.

I blew the reverse gear in my 1990 chevy C/K 1500 4x4 (damn blizzard) and the transmission is the 700r . the aamco service center gave me a great price ($1350)but then he added that it may need a new torque converter ($400) which would bring the total to somewhere around $1850.I thought this sounded weird because the truck still drives forward therfore I assume the torque converter is still working

So my question is this:

Does a torque converter need to be replaced if I only lost the reverse gear in my truck.

Thanks in advance
Ed

I am pretty sure you would not, however if you don't you may spend another 800-1000 bucks later on if the old one fails. It takes almost as much work, so it is a real good idea on a truck that age to do it. I know a friend of mine who went through that a few years ago. Best to do it.
It may have wear or damage you won't see until removed but even if it looks OK I would replace it.

Anytime you have internal tranny damage, it is a good idea to have the converter replaced. Debris could have gotten in there. Also, when driving in 3rd or 4th gear you would feel a shutter, not associated with tire balance. If that is the case, the converter is most likely bad.

I would replace it. Its gonna come back and bite ya later on a 700R4