So I have a little shake at idle and what sounds like gear noise under moderate acceleration. Heavy acceleration quiets it. Coasting or light acceleration quiets it.

I have a 2002 FRC 6M with 80k on the clock.

I also live in Phoenix AZ so it has seen dry heat which I understand will go hard on the rubber torque tube parts.

Thoughts? Suggestions? Am I on the right track?

 

Not sure about the shake at idle but the C5 is known for a "rattle" in the torque tube when starting off. It is normal and even covered in the owners video that GM made for customers.

I don't recall if the "rattle" is there for just manuals or if it applies to automatics also.

Look at this.

https://www.corvetteforum.com/forums...ers-video.html


Mr. Sam

 

EXCELLENT Review!!

Torque Tube Rubber Couplers:

I've have had a number of C5 Torque Tubes apart over the past years and have been surprised at several of the disassembles:

1. I had my 02 ZO6 TT apart during my clutch replacement. It had just about 50,000 miles on the OEM drivetrain. I was expecting to have to replace the rubber couplers. To my surprise, they looked brand new. I put my drive train through hell so,, I was expecting the worse. I did not replace them and their happy supporting 450 RWHP.

Every A4 (automatic) TT that I have disassembled, had excessively deteriorated couplers. Each one had over 80,000. The couplers are cracked and weak. Some worse than others. None of them were damaged enough to alert the driver of any issues. All of the Torque Tubes that had bad couplers were the smaller 10mm rubber coupler.

Long story short; Unless you are willing to remove the TT and inspect it,,,, IF,,,,, it is the TT causing the noise, you just have to live with the issue.

DRIVE TRAIN and Tunnel Plate

When I do drive train work, I normally see improperly torqued or LOOSE tunnel plate fasteners. I even found them loose on my 06 MN6 Coupe when I installed headers. I'm not saying thats the noise that you hear but its something to check if you have the car off the ground.

The rear wheel hubs / CV Joint output shaft NUT can get loose. When its loose, the DRY RUSTED SPLINES between the Hub and Output Shaft can make a noise that is amplified when you go to power to coast. If you find the nut loose, you can remove the nut, spray some motorcycle aerosol chain lube into the spline shaft area, clean the threads off shaft and retorque the nut.

IF,, you have manual C5, there is a noise that you will sometimes hear when you shut down the engine. With the engine running (IDLE), transmission in neutral, clutch released and (set the E brake for safety). Turn the ignition key off and you will most likely hear a loud rattling noise as the engine coast down to a stop. If you repeat the same process but have the clutch depressed, you will not hear it.

Each splined shaft in the drive train has an engineered amount of slop so they can slide freely. That clearance will oscillate as the engine shuts down. The compression / vacuum of each cylinder as it coast to a stop causes that oscillation and thus the noise. Its normal.

 

What I'm getting is a whine. Not really a rattle. It's done it since I got the car. Almost like rear end noise but seems to be coming from further forward.

 

Maybe get a good recording of the noise and post it.

 

I'll give it a try.

 

My 99 has the exact same issues. Have you had any luck figuring out what it is?

 

I'm guessing its rear end noise. Maybe a fluid change will help. It sure sounds like that.

 

I would check the fluid level first in the rear and go from there.