92 chevy lumina euro 3.1 4t60trans
the problem is when the car shifts at 35mph i get a little shake. not much but goes away at 37mph... when it shifts at 50 all hell brakes loose and the car wants to fall apart at normal gas....if i punch the gas it is ok....when speed reach 65...stops shaking and shakes at 70mph till 90mph....I got a computer code that said egr valve or vacuum leak.... so i did the egr valve and it got worse cause i got the wrong gasket from the idiots at advaced auto....fixed the gasket and still same problem have checked all vacuum lines and tested the vacuum modulator on the trany it was good and my friend know more about cars airplane machinic told me that the vacuum modulator only controlles 1st and 2nd gear shifts so i ruled that out.... the engine runs fine without a load.... i think it is the transmission.... which i just did the filter on.... they said that the transmission is not building enough presure...could i have not put the filter in tight enough and it of come loose and caused the transmission to not be able to build enought presure or am i going to have to buy a new car
thanks to all who can help
