I have a clicking noise underneath my car close to the tranny somewhere. My tranny is the stock 700R4 and it's an 87' Z28. I think it may be my torque converter, but am not sure. When I put the car in gear and have my foot on the brake, I hear a scratcy, clicky noise under the car. Yet when I put it in park, it stops. If it is the converter, what would be a good replacement for it that's not more than $350. I've heard that a B&M Torque Master is good. I want something that's good for street performance. I just rebuilt the engine about 20,000 ago and I'm positive that it's not the engine. If it's not the converter, then what could it be, and what should I do/get to replace it? My specs are: 355 c.i., heads from a 305, 4 bbl. stock carb, shorty headers, 2 1/4" duals, and a K&N.

Really sounds like a bearing problem to me, atleast thats exactly how my GTA sounded. Is the noise only at idle? Try this: with tranny in park/neutral, rev the engine to about 2500 steadily for about 5 seconds, and let off... if you hear a knocking sound as the rpm is coming down, the chances are its a bottom end problem.

...sounds like a cracked flex plate to me...they mimick a rod knock when there is little or no load on the converter...happens more than you really hear about it...just my $.02...

Well, it's not a bearing, because it doesn't do it when it's out of gear.

As for the flex plate, is that the thing that covers the flywheel and converter on the bottom of the tranny. If so, I don't have one of those on there for some reason, it's missing. I'm not very mechanically smart, but my father is. I really need to get that plate to put on the bottom. Thanks anyways, guys!

The flex plate is the thing that your converter is bolted to. If you climb under the car(I disconnected the converter)and pray between the flex plate and the oil pan if you hear a clicking noise youll know your flex plate is cracked and the transmission will have to come out to be replaced. But dont pray to hard cause you might crack the flex plate when its not even broken.Good luck on finding the problem.

a cracked flexplate will tick/knock when the car is in park also.

I replaced the converter and that seems to have made the noise go away. I also made the car run a little smoother. So, I believe the problem is fixed. Thanks for your inquiries everyone.:rockon:

Will a cracked flexplate diminish performance?

heh yeah when it breaks completely.you will go nowhere fast. the longest i drove on one of the 5 flexplates i have broken is like 30 miles. if its cracked it will just get worse the longer its driven.