93 C4 396LT1, Okay, at 2500 rpm and at 4500 rpm I have a vibration under medium to heavy throttle. Does not matter if AC is on or not.
In neutral, or park, the problem is not there.
Had main drive shaft checked. Good, and balanced.
Half Shafts have zero movement, and as driveshaft, has spicer u joints. They are a few years old, but very few miles.
I replaced end links on rear sway bar. Rubber was gone.
Hal Shocks, no leaks.
DRM Long tube headers since 2001 era, and OEM cat back exhaust.
700R4/4L60 Automatic ( built a long time ago, but has about 5000 miles using Pro Built Auto kits Street/Strip) with Vigilante 2800 stall
New tires.
Center beam has ZF Docs plates, and they are torque per FSM.
When you get on it, half or full it feels like something is vibrating/hitting the floor boards. Feels like exhaust is hitting. But, when I was under there, I cant see where the exhaust could be hitting. Maybe under torque, it is. Motor mounts are tight, I just did that a couple days ago.
So, thats all I can think of.
Thoughts, suggestions?

 

Try a corvette forum

 

This forum deals more with the 700R4, and I am looking at experienced people here.. So, if its okay with you, lets see if I can get some ideas of what ,ay be happening with a 700R4/4L60 transmission going bad possibly.

 

didn’t realize your question is directed towards a transmission question

 

Driveline is in the title. If people can tell me common issues with the transmission, I can deal with it..

 

Google common issues with 700R4, or use the search function in the forum. Or try that in a Corvette "driveline" forum.

 

Okay. I will search again.
I only belong to one corvette forum, and its not the big one.
You have 700R4s, I will search again. Its terminology that search works off of too.. Maybe I am not getting it right.
And there are no Driveline corvette forums, just tech..

 

Look into what the car was doing immediately prior to the issue arising.

Did it sit for a very long time?

Did this happen suddenly and you drive it every other weekend and it just all of a sudden started?

Regardless of parts specificity and make/model the answer to these questions can help you narrow down where to look.

 

Car did sit for 8 weeks in garage.. battery maintainer only thing on it.
Tested more.
Vibration in all gears same rpm.
Pushed brake to see iff TCC disengaged, it did.
Torque braked a bit at stop, and vibration is present.
Opened hood ( clamshell hood I can see easily), went back and forth with reverse to drive. Engine Barely moved. Idles at 800rpm.
In neutral nothing.
The rpm is happening at/close to stall speed of the Vigilante Converter. Does Torque Converter clutches attempt or try to engage, even in 1st.
My lock up settings for 4th is 50, 47 in low gears. I dont think my ECM allows individual gears, in 1993.

 

SOLVED. I have found the issue at hand. Left side/drivers OEM exhaust is/was touching in two spots on body. The shield was touching the body.
Also, the header triangle plate was touching ever so slightly.
Its not fixed, as I need to figure out what was wrong with the exhaust to touch. Is it bent ever so slightly upward?
The header collector clamp needs trimming..

 

Thanks for posting your results.

 

That’s better than the alternatives!

Maybe something settled, who knows. Hopefully you can just make some adjustments, maybe a little persuasion with a hammer, and not worry about it.

 

I may put a clamp around the heat shield and tighten it to squeeze heat shield in. . Then when I get back from travels for work, drop the exhaust after marking it and ever so slight bend it down somehow. It looks like it is bent. There is a hangar bracket further back that is not straight too. This is not the factory exhaust that came on this, but from another year.. Same part number.