How about the rear drums, or discs?

 

How do you know? That's always been the issue.

Chuck

 

Change 'em out I guess, or maybe swap them over to the other side.

I did read here somewhere once a guy had an outta-balance drum that drove him nuts.

 

DUHHHH, Maybe a break through.

OK, guys. It’s time to eat a little crow.

You guys must be SICK of reading this, but maybe this is a break through. I only took short rides when testing the car over the past couple months so I didn’t see one very important factor that I saw today on a long ride.

When I am doing 75+ and in the vibration mode, the vibration stops when I put it into neutral. I was asked about this before but I though the vibration stayed….but it does not! The vibration is mostly under slight acceleration or steady state driving and is there under deceleration but somewhat less pronounced. It does go away when in neutral at 75+ MPH.

I assume that means that the vibration is from the tranny forward, but I have no clue how to pin it down. Any fresh ideas or have I burned you all out?

Thanks a million.
Chuck

 

Suppose you take it to the point where it is vibrating, stick it in neutral and then rev the motor the the RPM that it would be in gear. What does that do?

 

Transmission bearings and yeah tired of this one.

 

Chuck,

What kind of clutch are you using?

 

I am using a Center Force 2.

This was a .82 OD car and a dealer recommended by Classic Chevy 5 Speed changed out the main shaft to make it a .64 OD. Just a little factoid.

I am only at 2100 RPM. Reving does not change things since I am turning 2100 rpm in many gears and there is no vibration below 71 MPH.

Chuck

 

This has been one of the most interesting threads I have ever read regarding this issue. I have a pinion angle issue as well...a big issue actually, so I am sure that this thread will help me solve the issue. IMO, this thread helped tons of guys that didint even post.

 

Well, I have to tell you, I think I burned out everyone in this forum but there are also lots of people with this same problem. Pinion angle is easy if explained correctly. Jim at Classic Chevy did a good job.

I still have a vibration that I can't find but I think we have all learned a lot. Thanks for the support and the patience everyone. I owe you all a beer.

Chuck

 

Chuck, is the transmission still shifting as smooth as it did new, from 1st to 2nd gear or has it stiffened up some between those two gears Jerry

 

It still shifts very smoothly, Jerry. I am happy with it.

Chuck
What kind of fan is on your motor? If its a fan with a clutch or a steel fan, take it off and just use short bolts to hold the pulley on so the water pump works. As long as you're moving more than 25 MPH it won't overheat. Take it for a spin and see what happens.

Jim, It's a new fan. I just ordered a new clutch and matching heavy duty fan from Summit Racing. I called the factory and they made the recommendation for a rugid, low noise fan. The vibration is when it's cold or hot. The fan is not running during my tests.

I think I agree with Jody. I need to locate someone in the SF Bay area who can do a vibration test.

Chuck

 

Chuck
What kind of fan is on your motor? If its a fan with a clutch or a steel fan, take it off and just use short bolts to hold the pulley on so the water pump works. As long as you're moving more than 25 MPH it won't overheat. Take it for a spin and see what happens.