Ok I tried searching for this but to no avail. When I am at a stop and accelerate slightly hard I hear a loud grinding noise and feel no power (as in the car doesn't really move until the grindin gstops. This also happens when im cruising at a low speed and step on it. I know im in desperate need of a tranny rebuild but im wondering if this is another issue altogether. Maybe its the flywheel? Perhaps my torque converter is screwed or the lockup switch is screwed up? Does my car even have a converter lockup. Its a 85 Camaro sports coupe carbed. Any suggestions are much appreciated

 

First, there IS a TCC on your auto trans. That, however, shouldn't even be involved until the vehicle is moving at 30-40 MPH under light load. Failure mode is usually released, and noise is typically rare. I'd be looking elsewhere first.

Can you describe where the noise is generated? Trans area, rear axle area, front of engine? Does the same thing happen in reverse? (Test this in an open, safe area.)

If you can raise the vehicle it may be good to check the driveshaft at the tranny tailshaft and rear axle input pinion yokes for excessive play. Lock the trans in Park and move the rear wheels with an assistant to try to induce and observe movement in the driveshaft. With the vehicle safely raised, start and operate it to listen for noised from the underside.

Have you removed the trans pan and filter to inspect for debris?

 

Do the engine RPMs come up a lot when you hear the noise? Or does it bog down? Does it do it at high speeds? If the above checks rule out the rest of the driveline, it sounds like it could be the forward sprag clutch. Its been ages since I messed with a 700-R4, but I think you can check it by sticking it in manual first. I seem to recall the low/reverse roller clutch aiding the forward clutch when 1st is selected. Try giving it some power with the shifter in 1st and see if its any better.