motor mounts are fine and transmission mount is new v6 running on all 6 no problems that are known but car has a vibration and im looking to get rid of the vibration..any ideas on how to fix it. oh and a new harmonic balancer all new spark plugs valves have been adjusted and timing is right.now and ideas????

 

Is it an engine vibration or chassis vibration? Might need to balance your wheels. Also, use a torque wrench when putting the wheels back on. That alone can cause vibration issues.

 

Its an engine vibration 100% sure cause we havnt even test drove it yet due to legal reasons..

 

Have you recently had the trans out of the vehicle? Before the vibration.

 

no i have not had the transmission or motor out at alli have done every thing that i can think of to get it to go away and its still there

 

You stated it is a engine/trans vibration because it does it when it's not rolling so you can rule out the drive train. I had a similar problem with my 355 and 700r4 combo. It took me a while but I read a post that described how to fix it from a retired GM mechanic. Apparently in the 80's it was a problem on many cars. Here's what I did to fix my problem, I changed the position of the torque converter on the torque /flex plate. I marked the orientation then removed the three bolts, spun the converter a third of a turn, then put it back together and the vibration was gone. You may need to try the other position as well. I guess the weighted torque plate and converter can be miss matched which will cause a vibration. My car had a drone at 2000 rpm in neutral and park until I changed it. Give it a try it might work.

 

ok i will try this when i get home thanks again and i will keep you all updated thanks again for the input

 

Here's a copy of my post regarding a drive train vibration. The test described by 1983Zsled is the described in this post.

"....It's been a long time however it looks as thought the vibration issue has been resolved.
Unintentionally no less.
For the record, EVERYTHING in the drivetrain has been removed, replaced or rebuilt at least once. Check out this thread for the list.
I've been driving with this problem for a few seasons and had resigned to myself to accepting that this is how the car is going to be.
Recently I had a 700R4 3-4 clutch go away. This trans with the TCI Street Fighter convertor helped the car to it's first sub 13 second pass.
I found a low mileage 700R4 from a forum member, did a quick shift kit, basic mod procedure and installed it with same convertor. Now it only took 4 quarter mile passes to cook this transmission ( that's another story ) however, the vibration is GONE. I have only 1st and 2nd gears to test with but I can say at all previous test rpm's, there is no longer the ' harmonic vibration' that was painfully obvious before.
I can come to two different conclusions. Two previous 700's ( I'm on my third ) and 3 different convertors all combined to produce the vibration. This I find unlikely.
Or the relationship between the flexplate and the convertor had a stacked up tolerance with respect to balance ( and I have been using a new SFI flexplate and new TCI convertors as well as an engine balance). After the latest installation, the convertor and flexplate were bolted together not using the previous index marks. Now it's smooth as silk.
After investigating further and going through the GM manual, I've come across a chapter titled " Flywheel Assembly/Torque Convertor Clutch Vibration Test Procedure ".
Who knew?
The test describes checking for vibration in park or neutral, decoupling the torque convertor, rotating it 120 degrees and hooking it up again. Check for the vibration and repeat the procedure if the vibration is the same or worse. Looks like when I reinstalled this latest trans and convertor I inadvertantly came across the best connection.
It was a long time coming. And expensive too although I must say I've collected and installed a lot a top quality parts along the way...."

Since you haven't disassembled your engine/trans I doubt that it will solve your problem but it is food for thought.

 

Thanks Skinny Z for some reason I couldn't find it......

 

ok so i tried this last night. and the second time i turned it to the next bolt hole it was just as bad but the first time that i did it the problem seemed better and now the car feels like it has a cam in it but im not sure if it does have a cam or not because i was told it was a stock motor but to me and my father it doesnt seem like a stock motor at all

 

If the engine is running rough it is going to cause vibrations.....
A lumpy cam will make it run rough to some degree....
If it isn't the cam there could be several Causes for the engine running rough
I would try plugs, wires, cap, rotor first....You might want to check the fuel delivery sytem as well.

Also when I did my 350 swap I neglected to bolt up the 3" cat back exhaust with the exhaust support off the rear of the transmission. I noticed the 3" pipe would vibrate at higher rpms, like a harmonic resonance. The pipe would move 1/2 to 3/4 of an inch side to side vibrating. I modified the stock mount and it solved that problem. Just Something elso to think about.

Good luck