[Ropper]

Have a 68 Camaro I just bought has a 383 4-sped. I have a vibration in the shifter. And gets worse and worse as I go up in RPM. Motor pulls hard so I don't thing it is a miss or anything like that. From the receipt I have from the machine shop that built it said rotating assembly balanced. So I'm not sure where to start. Harmonic balancer, flywheel, or maybe trans problem. Very new looking drive line and u joints. I don't think it's anything like that because the car isn't vibrating the shifter in my hand vibrates bad. Any help would be great.
Eric

[prostreet6t9]

Originally Posted by Ropper

Have a 68 Camaro I just bought has a 383 4-sped. I have a vibration in the shifter. And gets worse and worse as I go up in RPM. Motor pulls hard so I don't thing it is a miss or anything like that. From the receipt I have from the machine shop that built it said rotating assembly balanced. So I'm not sure where to start. Harmonic balancer, flywheel, or maybe trans problem. Very new looking drive line and u joints. I don't think it's anything like that because the car isn't vibrating the shifter in my hand vibrates bad. Any help would be great.
Eric

Can you Rev the motor up in N sitting still and get it to Vibrate? If so your probably right about it being motor related. You could unbolt the converter and push it back and start the motor and see if the shake is there. That would tell you if its the converter.

Do you know if the Driveshaft is a original shaft from a 67-69. You can tell a original by the tube yokes being a little out of phase. Extra care needs to be taken when balancing the original shafts.

[Ropper]

I'm going to try the neutral rev tonight. That was my next plan. 4-speed so no torque converter. I don't think it is driveline because speed doesn't seem to effect it engine rpm does.

[prostreet6t9]

Originally Posted by Ropper

I'm going to try the neutral rev tonight. That was my next plan. 4-speed so no torque converter. I don't think it is driveline because speed doesn't seem to effect it engine rpm does.

Oops.. Guess I should've asked about the 4-speed part..lol Probably not the converter then huh

[Custom10]

The 383 was it internally balanced or not? ask the shop, using a neutral balanced flywheel and neutral harmonic damper is needed for an internally balanced motor.

Most rotating assemblies are labeled "balanced" but need to be actually balanced by the shop during assembly for a true internally balanced motor. This is the best way to go since some crank/rod/piston assemblies are way out even though they claim balanced when purchased.

If they put a 400 flywheel with counter weight on an internally balanced motor you may have your issue.

If externally balanced then the whole rotating assembly including the flywheel needs to be done together. Not having the flywheel when they did a externally balanced setup could lead to issues

If the car had a 350 in it originally that flywheel would be neutral balance and can not be used with a 383 that is externally balanced unless the fly wheel is modified to match.

I am no engine builder but that my understanding of it, you need to know what it is external or internally balanced and what type of flywheel/damper you have

[Duntov]

I'm interested in seeing how this one comes out...

[Ropper]

I just checked the specs on the 383 crank and it is an external balance crank. Tommorow I'll get the car in the air and see if the flywheel and harmonic balancer have weights on them. If not, I know I'll be buying an external balance flywheel and harmonic balancer. This is why I don't like buying a car with a built motor that I didn't build or spec out myself.

[eloc431962]

Have you checked the grease in the transmission ? Could be something in the transmission . Make sure the trans mount is in good shape also. JMO


Cole

[2old2fast]

there is a "balance plate" available that bolts between the crank & flywheel to make an internal bal. wheel external. save you money!


dave

[Ropper]

Where do you get this. I have never heard of it. I would still need an external balanced harmonic balancer would'nt I ??

[eloc431962]

Originally Posted by Ropper

Where do you get this. I have never heard of it. I would still need an external balanced harmonic balancer would'nt I ??

Here's what he is talking about. http://compare.ebay.com/like/2004984...=263602_304692 .


Cole

[2old2fast]

yep, that,s the plate .Competition products &others also offer it . you need to check w/your engine builder because thier are 383 kits that are internal bal,ext. bal.& front external/rear internal. check out strokerkits.com. &" see all the possibilities "[ that,s what they used to say on 'make a wish'] but if your younger than 45 you wouldn't understand.

[Ropper]

Got home a bit ago and reved it in neutral vibration was still there but not near as bad. Looked at the harmonic balancer and from what I can tell it's an external balance style. Part of it is definitely larger. I will get underneath tomorrow and check the flywheel. The motor was built 7 years ago and the machine shop said it would be an external balance style even though they balanced the rotating assembly. I also found the part # at Summit and it's a external balanced crank.

[Ropper]

Took a look this Am and both the balancer and flywheel are weighted so I'm not sure where to go know. I'll probably look at the trans soon and see what if anything might be a problem.

[2old2fast]

check the condition of your motor mounts. if thier really worn or have 'age hardened" or really loose or seperated, you could just be feeling more than normal vibration transfer.