i need some help with this vibration. i have a 68 camaro with a 454 520hp
the engine was balanced. soild mounts all teh way around.
the car ran well last year even when hooked up to a th350 which i knew it would not hold so i was on a look out for a 700r4.
i picked up a unit from monster motors in FL.i installed it and it had a vibration a very bad vibration withing 25 miles of trying to find out the problem it snaped the case by the pump. monster motors did send me a replacment because we thought it was the convertor. i installed the new unit again and a new convertor and still have a vibration the vibration comes in at about 1500 rpm and in park.
with the convertor disconected it has no vibration at all and it had none with the th350.
the covetor is a non lock up which they supplied with the tranny.
i was told by the a local tranny shop that it was the engine and the mas of the covertor was makeing it worse.
i do nt belive that. because with it disonected even with the solid mounts it has no vibration at all and can rev up very easy

the flex plateis a tci and is in perfect shape.

i have never had any problem like this and i have work on cars for 20yrs
untill my back went out thats why its an automatic and not a stick

thanks in advance for any help

That flex plate is for a 454 is it not??? Or are you using the same one you had with the 350TH?

yes it is for a 454 .

yes it is for a 454 .

Well you got me, unless the flex plate lost one of the weights that they weld on. The converter should be neutral balance. You said it spins okay with no converter bolted on, then I'm leaning toward the converter being bad.

bry,
I agree with the others, if there was no vibration with the old trans. And there is no vibration with the converter unbolted, then your flexplate and engine are fine ... it has to be something in the converter or trans. You dont have your profile filled out, so we dont know where you are located, but I would take the converter out and take it to someone local that repairs, or rebuilds converters and have them check the balance on it.

you didnt say anything about the driveshaft? if you went to a 700 you would have had to go with a shorter driveshaft was it cut and balenced right?

i had a drive shaft made and the vibration is there in park as well
i am going to swap mounts to rubber to test it out
but i dont think it will work but i will try to rule it out
i will set up the profile later today

thanks again

bry,
The mounts might make you not feel it as much, but the vibration will still be there and will probably cause a problem again. One thing that I just thought of, is it possible that the hole in the back of the crankshaft is worn real bad for some reason, causing the converter to sit crooked when pushed into the crank ?? I think it would have to be pretty bad, but you never know. It should be a fairly snug fit.

with the trans out of the car no vibration with the trans in the car and convertor disconected a litte vibration
i saw on a web site to try and unbolt a and spin the convertor
one spot at a time and see if it helps, it feels better and i notice with the new trans and cross member in the pass side header was sitting on the idler arm i shimmed up the tranny and the rest of the vibratin was gone

thanks again

i thought it was done but it is better.

the vivration comes in at about 900 rpm seams to fade out and comeback strong at about 1800 and the vibration is in teh steering wheel and body and fades out at 2800 to 3000 rpm.
it comes in at throttle up and if driving same rang on decelaration as well
the engine wa balanced the flywheel is correct and fine th vibration is there with the convertor disconnected. new drive shaft but it does it in park.
the headers are clear from everthing by at least 1/4".

the vibration sounds low and sounds even throught the whole car.
the engine does not apear to be vibrating looks steady

it has a 520 lift cam so the idle and shake seem to be normal

i have looked at the valve springs and they look fine

i dont know what direction to go in

all rubber mount both body and engine/trans all new

I'm sorry, but I GOTTA say, a 520hp BB with a 700!

I wouldn't run it on a bet!

I would run a hopped up 200 tho.

AND I hope it is something simple causing your hassle too b/c this crap get's expensive to fix, imho..

I know, I'm outta line here too..............

pdq67

Did you put in a new flexplate when you installed the 700R4? Just thinking out loud - if you did, perhaps you got a flexplate for a 400SB instead of one for a 454BB? I believe the weights are different.

new flex plate for a 454 with weight on it
i went to far in the engine build up but a 454 was my dream engine for years
i dont plan to run th ecar on the track i just wanted smone thump and i have a a very bad back so thaty why the auto matic

Its got to be that converter or the pump in the tranny. What else would vibrate in neutral but not with the converter disconnected? How much else is actually spinning inside the tranny in neutral?

i think the 700 r is out and i will go with a 400
thats two new and bad 700 r's and i dont like the shift