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Discussion Starter #1
When I installed my engine I didn't even consider this. I just tightened it down.. I have a slight drivetrain vibration when I'm going above 65 and I'm just trying to track it down.

Is it necessary to center the trans in the tunnel somehow or is this not adjustable? I don't recall if the mount was slotted to allow you to slide it side to side..

-Tom
 

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It is not necessary, there are many Nova's that were off center from the factory with no vibrations. The 3rd gen BB cars were off center and all 4th gen cars are. The 2nd gen Camaro is also built that way.

Proper up/down angle at both ends of the shaft is important.
 

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if you notice the engine frame mounts, the driver's side is taller than the passenger side...

your engine is offset 1" by the factory...
 

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Discussion Starter #4
I did notice that when I installed the mounts.. My trans is not properly centered up and down perhaps this is the cause of the vibration. How do I change it? Just change out the trans mounts till its right? I have this on it now:

http://www.oreillyauto.com/site/c/d...=Search_C2251_1324404_2887&pt=C2251&ppt=C0338

The original had holes all the way through the rubber it was so worn out. you could still see the chevy symbol on it tho lol.

-Tom
 

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This is my belief...it could be because of the alignment. These novas were never designed to do our current highway speeds. I'm not sure what the standard highway speed was back in the day but I don't think it was 65mph. FWIW, my nova also starts vibrating at 65mph. I have a TCI clip to drop in but not ready yet. For the others that have it already installed, maybe they could chime in and say if the vibration goes away with the new clip (because TCI has their own alignment specs, although probably similiar to the cars' original specs)?
 

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the engine and trans are on a rearward downward angle... as designed. the mount you have is a replacement style mount. it's not supposed to be any taller or shorter than a factory style mount.

if you have a vibration while idling in park/neutral you could have a possible internal out of balance condition, a bad harmonic balancer or depending on engine size, possibly the incorrect flywheel/flexplate or balancer.

what size engine is this? if it's a 400 it's externally balanced as is a 454, they have additional weights on the flywheel/flexplate and on balancer... all others are internally balanced.

if the vibration is in drive, it could be tires, alignment, u joints, suspension bushings, ball joints, idler arm... numerous things to check.

what condition is the car... what has been done to it, what hasn't been done to it?
 

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Discussion Starter #7
The engine is a 283. Nova block. Its all stock and completely rebuilt with new pistons and stuff. New engine mounts. I rebuilt the front end with new parts and the bearing conversion kit for the idler arm. It was aligned after the engine was installed. I don't think it does it in neutral.. I think its only in drive. The tranny is the original 6 cyl one to the car and is very old.. So it could be the cause of the vibration. I'm going 200r4 but can't afford the parts just yet.. I remember it vibrated when I was breaking the cam in, in neutral.. I added more trans fluid and the vibration went away.. It had 4 in it at the time but the pan was dry so I added two more and it went away.

I had to use a couple of big spacers between the flywheel and the torque converter to get it properly seated in the trans.. The flywheel is the stock one thats been on it since the factory. it was the same size and looked identical to the old 6 cyl one. The machine shop checked it out and told me it was ok.

When I installed the motor I replaced a leaky pinion shaft seal and refilled the diff and installed new rear shocks.

When I had the old 6 cyl I don't think it vibrated.. Maybe it did and I couldn't distinguish it from the knocking of the engine. The car has a smashed quarter that a PO covered in bondo.. So it is possible the frame isn't perfectly true but I recall looking under the car and seeing a slight crease in the inner fender so I figured the energy from the accident was expelled there before the frame rails.

I can jiggle the drive shaft and there is a little bit of play where the yoke goes into the tranny. Normal?

-Tom
 

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yeah, i don't know what to say... spacers between the converter & flexplate?

that sounds wrong...

the distance from the back of the crank to the front pump on the transmission hasn't changed in a zillion years. so if spacers were used there's something not right with something...

hard to diagnose something when things aren't put together "factory" even aftermarket parts are supposed to be within specifications. so if parts are "made to fit" i'd go back and check those items first...
 

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yeah, i don't know what to say... spacers between the converter & flexplate?

that sounds wrong...

the distance from the back of the crank to the front pump on the transmission hasn't changed in a zillion years. so if spacers were used there's something not right with something...

hard to diagnose something when things aren't put together "factory" even aftermarket parts are supposed to be within specifications. so if parts are "made to fit" i'd go back and check those items first...
X2 if you had to shim your flexplate it is probally wrong one
 

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or on backwards. The raised pads for the torque convertor go towards transmission.

there is a raised edge on the center hole too... if it's installed backwards it's not going to sit flush against the crank and if drawn tight with the bolts it's very possible to warp the flexplate...
 

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Discussion Starter #13
there is a raised edge on the center hole too... if it's installed backwards it's not going to sit flush against the crank and if drawn tight with the bolts it's very possible to warp the flexplate...
It is possible it is on backwards or it is a flexplate for a manual tranny. IDK what was on the motor originally when I got it. I didn't ask. All I know is it came out of a 67 nova.

I will take a look when its on the lift at the exhaust shop tomorrow. They gotta fix a leak.

-Tom
 

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It is possible it is on backwards or it is a flexplate for a manual tranny. IDK what was on the motor originally when I got it. I didn't ask. All I know is it came out of a 67 nova.

I will take a look when its on the lift at the exhaust shop tomorrow. They gotta fix a leak.

-Tom
Tom, a flywheel is for a manual trans, a flexplate is for an automatic. ;)

yeah, if it's going to be up on a lift it shouldn't be too hard to shine a flashlight up there and check... easiest to view would be the raised pads Philip REFERRED to. ;)
 

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If the converter has to be pulled up too far usually 1/8" to maybe 3/16" then yes you would have to put shims between the converter and flexplate. If not the converter would be pulled to far out of the transmission pump. The shims or washers need to be close to the same thickness. It won't cause a balance problem, but if the shims or washers aren't close then you would see it when you crank it. I have never had to install shims in any car I have worked on before, but I have heard of it before.
 

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Discussion Starter #19
If the converter has to be pulled up too far usually 1/8" to maybe 3/16" then yes you would have to put shims between the converter and flexplate. If not the converter would be pulled to far out of the transmission pump. The shims or washers need to be close to the same thickness. It won't cause a balance problem, but if the shims or washers aren't close then you would see it when you crank it. I have never had to install shims in any car I have worked on before, but I have heard of it before.
This is what I did. The torque converter came out too far (over 3/16) so I shimmed it with machine washers all around. They are all the same thickness. I used two on each mounting location. One about 1/8 inch and the other about 1/16 inch thick. This moved the converter to just over 1/8 inch from the tranny which I deemed ok.

Flyer: There are no machined pads that I can see. I will squeeze under there and take a picture in a bit.
 
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