TeamSwift

So about a year ago I rebuilt the motor in my swift and ended up replacing the original factory trans (cause I broke it) with one from a junk yard and it works, but has a real problem with slipping.

The transmission runs fine at city driving speeds (0-90 km/h) but once I hit the highway the problems start. If I stay on the gas and dont stop accelerating it will work fine, Ive gotten it up to 150km/h and it still accelerates, but as soon as I let off the gas and than try to accelerate again, the transmission has no power and just slips bad, making the engine rev excessively. If I slow down to about 80-90km/h and than accelerate, the slipping stops and I have power again.

Also, Im not sure if this is a problem or supposed to happen, but if I let off the gas completely at highway speed and just let the car slow down naturally, the trans will surge, making the engine rev and bit. It almost feels like an engine brake but its not constant, it just surges. The trans will also slip in second gear, but only if it shifts into second at WOT.

Since I cant constantly be slowing down to 80 on the highway, Ive just had to put up with it, but its killing my fuel economy as I drive on the highway a lot, and I would rather not have to sell the car since this problem makes it practically worthless. I was trying to figure it out and I suppose that it could be the shift solonoids, but based on other topics about the shift solonoids I dont think it is, as all the gears still work and this problem only comes at highway speed (and WOT shifting but I thats honestly ignorable).

Is this an issue internal to the transmission or could I fix this just by doing some basic wrenching and not having to remove the transmission? All fluids are at the correct level and it docent burn or leak any fluid. I cant afford to spend much money on this car and im honestly a little sick of working on it after all the work Ive put into it so far.