Team Camaro Tech banner

1 - 4 of 4 Posts

·
Registered
Joined
·
16 Posts
Discussion Starter #1
Help!!
Recently I put in a new 383 stroker motor and Tremec 5 spd from Forte's in my '69 Camaro. I always had vibration with the old 350 and Muncie. After looking thru all the forums here, I decided I was going to spend enough money to stop it! Well.....After many thousands of dollars and lots of sweat, I still have a rather nasty vibration from around 3500 to 4500 rpm in any gear. Out of gear there is no vibration, as I rev up the motor. I had the pressure plate balanced, put on a different Chevy bellhousing, new rubber motor & tranmission mounts, the motor was balanced with the flywheel, had a new driveshaft built.
What in the world did I miss???? The car is fast, but if I can't fix this, I will be putting a FOR SALE sign on it soon!

Gary
 

·
Registered
Joined
·
571 Posts
Search using drive shafts. The old drive shafts didn't have ends that were aligned up the same for yokes to attach since a perfectly balance drive shaft is said to set a perfect spot for vibrations to cause a harmonic vibration on the drive shaft. Needless to say it could be many things besides the drive shaft. Maybe a flaking out HEI ignition. Maybe motor and trans mounts. How heavy duty are the accessory brackets. They might promote vibrations if a pully is bent or loose or not. Maybe try having somebody watch the engine from a truck with the hood off. Can't let a car beat you. Hope it isn't engine internals. Somebody once said their clutch brand new was out of balance. I gotta pump the clutch some times on mine to get mine to cut vibrations out.
 

·
Registered
Joined
·
16 Posts
Discussion Starter #4
Thanks guys for the input. The vibration goes away if at speed, the clutch is disengenged and let off the throttle, so I don't think it is not anything in the chassis. The motor is smooth if rev'ing at rest in the driveway. But in any gear, going down the road, the vibration is present about 3500 - 4500 rpm.

I'm thinking it could be a misaligned transmission/bellhousing. Several Chevy guys said they had never seen a stock housing cause a problem, so I did not check it before installation, and it did not seemed to be damaged.

Can the offset dowel pins from Lakewood be used on a stock bellhousing?

Is it possible I could have a timing or lean misfire condition only when the motor is under load?

Gary
 
1 - 4 of 4 Posts
Top