Heres the situation. Have had a Rockon Transmission LV4 and Fuddle 3400TC for about 4-5 months now w/ my 408. had them installed but the only tune i got was sending the pcm away to pcmforless which i know isnt that accurate. It drove fine but all of the sudden theres alot of slippage anywhere over 4000rpms but only when i give it about 80% or over accleration, otherwise no problem. when this happens in first gear it wont even shift into second it just revs up like its in neutral. Im really hoping theres nothing wrong with the new transmission or TC but does this sound like it could just be a tuning problem...i plan on dyno tuning within a week or so

 

anyone?

 

tuning might prevent the tranny from shifting, but your slippage is purely mechanical, most likely driveline problems

 

driveline problems, not the tranny or converter?

 

the tranny and converter are part of the driveline ....

The problem you are describing sounds like a transmission problem... when my first trans went out, if I gave it too much gas it would slip up and the car wouldn't go anywhere

Very doubtful the problem is tuning... unless you're still pressure controlled by the PCM and the PCM isn't commanding enough line pressure...

But I would think your new trans would be vacuum modulated?

Likely a mechanical problem

One thing to check... if it's vacuum modulated, make sure the vacuum line didn't get crushed


If the problem is tuning (not enough line pressure commanded, if you're not vacuum modulated) then the way the trans is behaving now most likely wouldn't be corrected by just changing the tune... clutches are probably worn pretty good (if the issue was low line pressure)

 

Driveline = Tranny, tq cnvtr, shaft, rear

1) If everything felt and worked ok at first and now it doesn't it is not the tune.

 

well is till have stock 10 bolt and stock driveshaft...is it possible they could be the problem? would any performance shop probably be able to figure this problem out for me?...its killing me to have spent so much money for problems. when my tranny before this one went it would slip like horist said give it gas and slip all the way through. but this is completely fine only until im heavy on the pedal another thing i noticed was the rpms kinda bounce up and down as if im playing a drum on the pedal when i give it 75% or over accelration even though im just steady on it.

 

Have you checked the tranny fluid levels? It could be something simple as being low on tranny fluid! Start simple and cheap and work you way up!