Severe Vibration Through Shifter

[Marty Rogan]

This is an issue with my '71 with an '83 L28 and '83 5 spd installed.

I had a combination of issues happen while on the track at Road America. First, I think the fuel regulator started to go bad. I lost power and died. Had to get flat towed in. While diagnosing the no fuel problem, I got the car running again. Then when I was revving the engine, I started to get a real severe vibration through the stick shift. There was also a bad noise coming from the back of the engine. I could not tell if it was coming from the engine, the tranny or the clutch. The only thing that I could think of that could have hurt something was that I messed up a down shift and it revved pretty hard against the clutch once. It seemed like I smelled some clutch material for a brief time after that, but it seemed to shift and drive wihout problem for a long time before the fuel issue cropped up.

At that point I decided to call it a day and limp home. I didn't get very far. The vibration got worse at 3,000 RPM or when I went above 60 MPH. I had to leave the car and come back the next day with a trailer.

Not knowing where the problem was and not having time to deal with it, I decided to drop it off at a Z Shop as long as I had it on a trailer. He thought it was a clutch problem. Once he took it apart, he found that the ring of weights on the CenterForce II clutch had slipped to one side. This seemed to make sense, that if the weights were off center, that it would cause a vibration.

I got the car back today. It still has a severe vibration that comes right up the shift lever. He thought it was the shift knob causing it. But I took it completely off and it still vibrates, so that can't be it.

At this point I am starting to think some is wrong with the trans. Anybody got any ideas what would cause such a vibration through the shift lever?

TIA,

Marty

[Darrel]

Did you drain the oil from the tranny and were there any bearing cage pieces caught in the magnet?

If you have an extra transmission put that one in and break into the old one.

[=Enigma=]

Have you checked the u-joints for play or checked the bolts that hold the prop-shaft to the diff. If one of them is loose or missing, it could throw the whole thing off balance.

[Marty Rogan]

I checked the u-joints and bolts. Everything feels tight with no play at all.

No metal in the oil either.

Keep the ideas coming.

Marty

[beezee]

Had that same problem years ago in a 340 Dodge I once had ,turned out to be a worn crank pilot bushing. It would shudder and vibrate right up the shifter.

[GreenZZZ]

I blew the input bearing on the tranmission for a '79 Mazda RX7. It made alot of noise when you pulled the clutch and went away when you pushed the clutch in, so I guess it was all rpm's, not just >3K. It was pretty obvious by grabbing the input shaft of the tranny and shaking it. The vibration from the input shaft ate up the pilot bearing where there was just a sleeve left (it was a roller type pilot bearing)...

[Bcalvosa]

Try a couple things to narrow down the cause:

1) With the car stopped, rev the engine in neutral with the clutch depressed, Vibration means it is not the transmission. Possible causes could be a broken flywheel, clutch cover or cover bolts, flywheel bolts, harmonic damper (aka balancer), crankshaft, connecting rod or piston (in rough order from bad to worse).

2) Rev it again with the clutch not depressed. If there was vibration in step one and now the vibration is different, the clutch and flywheel issues are more probable. If there was no vibration in step one and now there is, clutch disc, pilot bearing, or transmission main shaft / main shaft bearing is likely.

3) If step 1 or 2 did not produce vibration, the driveline is the likely culprit. Transmission, transmission bearings, or driveshaft u-joints are the most likely.

Good Luck...

[bigoak]

Umm...Bob...you're responding to a thread that is over 2 years old...

[Bcalvosa]

Oops. Forgot I was in search results...