transmision problem ???

the car is an 89 toyota tercel 4cyl automatic bout 205 000 km on it

ok so i no my car only has a 3 speed transmision...

wen i drive the car everything is fine on accleration as i gradualy go faster i see it shift from first to second and both those gears are fine but wen it gears up to third gear low end side of it is fine but wen i give it more as i reach above 2.5 grand in revs (i put a tach in it) it starts jerking back and forth and it sounds like something is cloged [i am forced to ease of the gas and let the revs go down] but wen i stop the car and give it realy high revs in neutral that jerk doesnt happen

i chekd transmision fluid, engine oil, coolant could it be the transmision or something stupid like air filter or spark plugs wich i admit i havent changed in almost a year

i am very concerned any help would be greatly appreciated

Check plug wires and the fuel filter. Both will usually cause this under any load even at lower gears but I have seen this before. Under load at that speed your timing is advanced way around and will sometimes a weak plug wire will misfire. At this speed and load you are needing a lot of fuel and a partially clogged filter may not meet this demand. Good Luck.

i drove it again and the problem has gotten worse i hit the high-way to see how bad things realy have gotten i was doin fine wen the car was going under 100 km/h soon after around 110 km/h the car started jerkin again and soon after the road became a huge hill and i almost didnt make it up and almost broke down the jerkin was so bad [reduced speed to 40km/h and jerkin was stil happening]

i am almost certain you are right public because wen i have situations were i have to give the car alot of gas when i need power out of the engine its like it doesnt want gas and jerks back and forth

Bad plug wires will get worse pretty quickly. The electricity just keeps burnin the hole bigger. Can also be a coil. If it is the coil or wires it will get to where it does not want to even idle. You can then raise the hood a night and start the car. It will look like a disco in there.

thanks alot for your help public i wil most def check those things out

Glad to help a "Gent"