Engine n tranny problem. Help! This might be the last straw.

[4THECHALLENGE]

I'm not sure if I have this in the right section if I don't please move it.(sorry)
this might be what really makes me give up on this car.
I had a 318 before had that replaced with a 360 they used the same flex plate, harmonic balancer off the 318 the trans is a 904 tranny and it was rebuilt. All parts are rebuilt we started for the first time and at around 1500 rpms there is a vibration.

We replaced the flex plate with a 360 flex and also the harmonic balancer for a 360. I only did this because the tech said he needed these parts and they would solve the problem. After 3 days later the car still does the same problem. What could this be?

Now he removed the weight off the flex plate but it still does it. I was thinking it was the converter.. But I'm really mad mow.
What else could it be ? Help?

 

[Chryco Psycho]

It could be a # of things , the 360 is externally balanced typically requiring the correct damper & a weight either on the converter or flexplate , but if you used an after market /lightweight piston the weight needed could be totally a different spec than either factory weight or no weight , the crank ,rods ,pistons ,damper & flex plate or converter should have been balanced together 

[moper]

Like CP said... the weight on the 360 is on the convertor, not the flexplate. So, you added the correct balancer on the front, but you didnt correct the out of balance in the rear. If the convertor is good and you like it, you can use the B&M flexplate and that should fix the vibration.

[torredcuda]

All stock parts or aftermarket-converter,flexpalte,balancer,engine internals???

[72bluNblu]

You need a complete, matched set- balancer, flex plate, converter all for a external balance 360. I would want either stock stuff, all off the same engine, or aftermarket stuff all from the same source at this point. Even then, as others have mentioned, it may not be perfect if you're running aftermarket pistons etc. Only way to know 100% is to have the rotating assembly balanced.

[4THECHALLENGE]

Thanks guys that's exactly what he told me today he talked to some guy that' races these things and that's what he said. It doesn't vibrate as much but I guess that it's better and I can live with it.  I'm just bothered because it's my first dodge and it's nit really making me happy with the way the whole thing is going.
Now that that's out of the way I need to get more money for paint.

by the way it has mild head work, a cam and Keith black pistons. I guess I'll just have to deal with it. This is why I hate performance!

[shadango]

I feel your pain man.  Similar boat here.

I have a 318 that I never heard (or more appropriately FELT) run before.....had a 727 tranny rebuilt and a new reman 318 convertor and have the same 1500 rpm vibration issues.

Does your vibration oscilate, ie go up and down in intensity? OR is the vibration constant and consistent? 

Mine oscilates and the oscilation gets faster as you raise the rpms....does it in neutral or drive alike.  There is a sweet spot at about 2k rpms where it is almost gone....seems to do it a bit more under load...or at least the vibration seems to change a bit under load...

I have replaced the farmonic balancer with a slick unit that has add-on weights so it covers all the small blocks...at least that gives me some options later.

I am at the point where I am going to have to swap out the convertor to see if thats it or not and then if not it is engine internal.

I know the weight on the flex plate should have worked in your situation, but maybe you do need the actual 360 weighted convertor?

Have you tried pulling the belts off the front of the motor and running it briefly to see if any of that helps remove the vibration?   I did and it didnt help but you may have luck with that.

[4THECHALLENGE]

well i drove it only for about a couple of blocks but it was very noticeable, the guy told me to replace the harmonic balancer and the flex plate and he did but it still did the same problem, he then talked to a guy who he says raced the cars in the 70s and he told him to take bith weights off the converter and then i found out he did this and scared me ..but it actualy solved the problem.

so far so good. i will be getting a 5.7 hemi in the next 2-3 years and i guess thats gonna be the way to go after all.

[shadango]

WHen you say both weights...do you mean off the front of it (engine side) or the back of it , or both?

THe 360 convertor is supposed to have a large weight on the front of it.....if he took that off, that means the convertor is now more like a 318 convertor weight-wise....

How would that work?

[4THECHALLENGE]

thats the first thing i thought... the tech said he had him remove both weights in the converter and when we started it i was mad  i thought it was gonna vibrate worse but after the idiling for a while and driving it around the blco  it was gone. maybe the tech explained it wrong to me because i think hes a learn as u go guy hes more like an installer but at least they got it fixed.

[torredcuda]

Changing pistons and other internals changes the balance so stock parts may not work.The only right way to do it is have everyhitng balanaced by the machine shop.

[4THECHALLENGE]

Changing pistons and other internals changes the balance so stock parts may not work.The only right way to do it is have everyhitng balanaced by the machine shop.

that means i would have to remove the whole motor right?  i thought of that but then i might as well drop in a 5.7 hemi. i can live with the way it sits right now. its not very noticeable

[moper]

The fact that you don't feel it only means the engine mounts are working. The engine will literally tear itself apart over time with an out of balacne like that. So I would start shopping for the 5.7L. It might last years, or miles. In any case, I would never leave a situation like that intact. It can be that bad..

[4THECHALLENGE]

Well my other option is to find a 360 from a Dakota fi and meanwhile hold on to this one. It really bugs me because I bought a motor from ATk about 4 years ago, installed it on my camaro and it has bad rings cause I'm getting alot of blow by and now this.. I feel like I'm just getting taken advantage of

[shadango]

Well my other option is to find a 360 from a Dakota fi and meanwhile hold on to this one. It really bugs me because I bought a motor from ATk about 4 years ago, installed it on my camaro and it has bad rings cause I'm getting alot of blow by and now this.. I feel like I'm just getting taken advantage of

Again, I feel yer pain....I guess this is why everyone doesnt have this hobby...LOL

I am on vacation and far away from my fish, but everyday I have been stewing over MY next step to solve my vibration issue....,.,.

I am trying to keep it in perspective...it is a HOBBY......but sometimes we get so wrapped up in it (we meaning ME) we forget it is supposed to be FUN...LOL