At 2500 rpm in nuetral or park i get a pretty bad vibration..... Im guessing it prob has to be the converter alignment? Or maybe flywheel out of balacne? It was a brand new tci flexplate.......

 

anyone?

 

im not trying to be one off those guy's that post on here being a**'s but i cant remember exactly what i had read, i think it was in the stickys, or on a converters web site... i cant remember but from what i can remember is its your converter, most likely and i think its the converter shuttering, and i know it said that if you bye a shift kit it will help... but i may be wrong, ive just been reading allot because i just ordered my new th350, and converter... but good luck

 

and this is what i was talking about... i found it on the fuddle converter sight, though im not sure if fuddle converters are any good? but i hope this might held?
or maybe someone els will chime in...

fuddleracing.com
6. What causes shuttering if it happens? Shuttering is a sign of Pulse Width Modulation. The more severe it is, the worse the shape your valve body (inside the transmission) is. Each time the converter shutters, you come that much closer to burning the clutch material and frying the converter leading to costly repairs. It can be fixed, see below...

7. How do I get of Pulse Width Modulation (Shuttering)? The number one thing you should do when installing the converter to help prevent PWM is to get rid of the check ball in the input shaft. It will go a long way toward holding the clutch as hard as it needs to be held. Since PWM is a computer controlled program, can be addressed by simply tuning the car to not pulse. Additionally, most shift kits will get rid of PWM completely. Occasionally an overhaul on your valve body might be needed, and stepping up to the Fuddle HP/Street will tend to remove PWM as the clutch is so huge that it simply won't move when it is being pulsed. Finally, moving to a lower gear (higher numerically), particularly if you are running a 4l60e with 2.73's, can also eliminate PWM by always running the line pressure at a higher pressure from the raised RPMs

 

The 400 does not have LOCKUP or PWM so could not be the cause

 

ohh well ok thats why i was wanting someone to chime in because im kindof new to this... but i figured i would share what i read...

 

Did the vibration exist before the flywheel was changed? Torque converters are dynamically fluid balanced and are rarely the culprit. When did the vibration start? What parts were changed at the moment it started?

 

It started directly after the trans swap.... parts changed include: trans crossmember, used art carr trans and converter, tci flywheel, custom driveshaft, and poly trans and ta mounts I know those mounts can unveil vibrations, but I didnt think that was it as it happens in nuetral

 

Time consuming and a little costly, you may want to send the converter in to check the balance. Since it is used, there may be some particle build up stuck in some of the fins on one side, (a 1/4 ounce of weight (7 grams) can produce 114lbs of force @ 7000rpm from the center). The flywheel is usually the culprit, altho I haven't seen any problems with TCI unless the wrong part # was installed. I use one myself. The poly mounts caused me some problems with vibrations, so I went back to the factory mounts-which means there is something not perfect in the balance of the motor or attached pieces. The factory mounts are more forgiving (40 durameter vs 90 for the poly mounts). Good luck and keep us posted.

 

I'm having the same problem after my 400 install built convert for the swap with the right piliot diam. but I'm running the stock flexplate it seems like the converter is out of ballance. if someone else could chime in could this be because the converter is not shimed