I have a new(500 miles) Performabilt level 2 4L60E with a new(500miles)Fuddle 2800 stall converter,I have my ECM programmed to shift to overdrive and lockup converter at 60 mph under normal driving.When car shifts to overdrive I experience a vibration after shifting to OD.No vibration driving around town only on highway in OD,is this a trans problem or converter???

 

does it only do it when locked up

 

OD and lock up occur at same time..really
can't tell

 

can you lock it n 3rd

 

Never tried, But I probably could by leaving in 3 and accelerating to 60.If it does it in 3, then its the converter?

 

very well could be clitch shudder.....

 

what fuddle did you get the street or the hp version... I can tell you this ill bet any money your fealing the clutch slip/vibrate when its going to lock up. Is the vibration constant or does it go away once locked? When its locked if you give the car some throttle to speed up a little does it vibrate like crazy while locked?

 

Vibration is constant from lockup at 60 and gets worse as speed increases.

 

is it a fast frequency vibe sounds like a drive shaft

 

Try this with the throttle steady use the other foot to gently apply the brake this should disenage the converter see if the vibration goes with it

 

do u have a poly trans mount? that could be it. mine doesnt start vibrating until around 75-80 mph.

 

I took car out on highway today, at 60+ I shifted it from overdrive into 3 and vibration got much worse??? I was thinking converter now I am thinking transmission??

 

Shifting to 3 would increase engine RPM Flex plate and converter would go faster where drive train would remain the same. Place the car in neutral and rev to aprox the the same RPM as the vibration occurs . What happens can you feel it?

 

sounds like the issue im having with vibration. Im on my second converter and the vibration is alot less with the replacement converter but i still have it which leads me to think this converter is also not balanced right. Hey atleast you have lock up..