I hope someone can help with this asap... I just had a repritable shop do a TCI sf 3000 torque converter install.. at the same time i had the tranny checked and rebuilt using all upgraded HD components as well as a trans-go shift kit. Upon completion, and road test, there is a very notible harmonic vibration /shudder at @ 3500 rpm. this vibration is constant even when held in gear (1,2,or3)to that rpm. even if I free rev the motor in neutral, the vibration/harmonics is still there all thou not as predominent. Upon heavy acceleration the car just fries the tires and as it flashes past this rpm you can still feel it. I am going to try and undo the torque converter now and spin it 120deg then bolt it back up (3 bolts hold it on) and see if this has an effect.
is there anyone else that might have a sujestion as to what is causing this???? We are hosting the corvette nationals this weekend in Grand Bend and am hoping not to damage anything.
Has anyone ever had this problem or is there a specific GM sequence that should be followed when re/reing the torque tube that might have been miss followed by my shop??!!
please help newby

 

Impossible!!!I have the EXACT same problem with the EXACT same tc at the EXACT same rpm.If we get a correct answer here ,you will be helping two very grateful people out.

 

yeh there seems to be alot of diff answers on other threads...I hope someone can give us the correct one.

 

If re-clocking the torque convertor does not fix it, be sure to check the basics - plugs, wires etc. When our car had a misfire (bad plug wire) There was a definite vibration when revving at certain rpms, although the idle and other rpms were smooth. Wires may have gotten bumped when the driveline was tilted for the trans install.

If possible get the PCM scanned for misfires etc.

 

If thats the case, I would start to think that it might be a bad batch of torque converters and move on to Yank or one of the other top notch manufacturers.

 

I installed a TCI for Corvette Fever magazine a few weeks ago. Same problem. Out of balance.
I just replaced it today with a new one. Problem fixed!

 

I'm having this exact same problem! Shop says it's from misfire but this wasn't happening before the tranny & TC were rebuilt. I'm changing out the plugs and wires today and we'll see if it's still happening.

 

Wow...my 98 A4 does that too, at exactly that RPM. The previous owner had the trans rebuilt/replaced last October at a dealership using the stock TC. I'd sure like to find out what it is, cause it worries me. I thought it might be the torque tube couplers, but now, I think it might be the positioning of the TC, since we all have had this problem since a rebuild.

 

my install is planned for monday....should i get my tc checked before the install ...can a trans shop check the balance???its new and it a ssf3500 tci
(2nd one first got lost by fedex)

 

Same problem here with a Yank 3000. I am working with MTI to try to get it sorted out. So far no ideas for a fix.

 

Mine was done at mti as well.I live 800 miles away though.
Mine seems to do it more when im turning sharp and accelerating though.

 

Ok I have a 97 with a fresh trans and a PI Vigilante 2600 multi disk that also vibrates at same RPM supposedly they are also zero balanced. I m gonna try the reclocking if that does not fix it I would say its somewhere else in the torque tube. I did notice that the old converter had a balance weight on it. But I would hope that would be just for zero balance of the converter and not the propeler shaft also.

 

It is starting to look like there may be a problem with the Yank 3000.

 

My issues turned out to be from misfire. Changed out the plugs and wires and no longer have any vibration.

 

I wish that was mine.I changed them awhile back.

 

New plugs and wires installed when the TC and headers were installed. The dyno tune after the install went well so not a wire or plug problem.

 

Can reclocking the TC be done without pulling the transmission?

 

Do I risk any damage to the tranny or other parts of the drive train if this problem is not fixed?

Ron

 

well I stayed up all night on thursday to get this thing sorted out.. I re-indexed the torque converter 120 deg (moved bolts one hole) and re torqued...what a pain in the *** to do on your own, you have to keep bumping the starter until the bolts show up in the inspection window of the bell housing. Then i loosened the shaft coupler through the inspection cover of the torque tube at the rear of the crank shaft. With the coupler loose I started the engine and let it run till it reached operating temp.. while up on stands i also ran it through the gears. I then shut it off and let it cool down then I retorqued the coupler. (the coupler will spin freely on the flywheel cone and will make a slight rattling noise when the bolt is loose (finger tight) and the engine is running...nothing to worry about. It seamed as if most of the vibration was gone untill today it seemed to return as the trans shifted into another gear at 3600rpm. Im going to move the bolts on the converter one more time and see if that helps or makes it worse.. otherwise its out comes the whole f-in chassy to send a torque converter back to TCI for a new one.... I wonder if TCI has a money tree that they can give me to pay for all this labour...Ya right. Hopefully some one else has another answer to this,... cause I really do not believe there can be that many new manufacturers of torque converters having a balancing issue...And I think those of you who have re/re'd your old torque converters in place of the one that was thought to be vibrating, must have just gotten the sequence of re/reing the trans/torque tube perfect and lucked out. Let us all who have this problem hope some GM engineer answers. max

 

It is a frustrating problem. I am almost thinking about putting the factory convertor back in.