I have a 99 Sierra 370 head and cam N/A with a FLT 4L65E level 5 and Yank TT3000 convertor. I am having a slight vibration when letting off the gas. I can't figure where it is coming from.

When I built the truck I did it all at once, Motor, trans, driveshaft balance, and rearend. So the vibration is driving me crazy. I was talking to my Dad today and telling him the simptoms of what is going on. He said it sounds like torque convertor chatter.

There is a little over 5000 miles on the whole setup in the 2 years it has been done. Can someone explain or describe torque convertor chatter. To see if I can rule that out .

Thanks

 

I'm having almost the exact same issue. ..only my vibration happens in 4th gear (OD) only at about 62-65mph in low rpms only. When I shift into 3rd it goes away, and or if I get on the gas it goes away too. It feels like the TC to me...I have the same brand as yours...it's a PT3200...

 

hey....
i am heaving the same thing ! i drive a hummer h2 with 8" lift and full boltons with some internal engine mods. the wheels are 39.5x16.5 rockers
the problem started about 1000miles ago and is getting worse:i have a vibration only when i let off the gas ! even if i am in N the vib is still there ! do you get a vibration when you are in N and just let the truck roll ?

 

check your pinion angle