F4A221 downshifting violently, auto trans experts needed.

[alexg1323]

i Recently bought a 91 laser with the F4a22 transaxle. No complaints upshifting really. It was full of dextron trans fluid so i dumped the oil pan which only allowed me to change 2qts not the rated capacity of 6qts with diamond atf. Is there a way so safely flush more of the trans?

Anyways the upshifting either wount happen or if the gas is pushed down very quickly it will upshift but very violently, all motor mounts are good. Also when breaking up to a stop there will be a moment right before the complete stop where the car lurches forward almost like the trans is upshifting to go again, but its very noticable.

So is this normal of the slow processor inside the TCU or is there a valve body i need to clean? Im not very experienced in working on the auto transaxle so please bare with me. thank youu in advance

 

[alexg1323]

I also want to add the TPS sensor is set correctly and the TCU is reading no codes

 

[BaddAssGst]

Why don't you drop the pan and change out the filter? You should be able to drain some/most of the fluid. You could even pull the cooler lines and let those drain as well.

 

[92awdgsx]

Its hard to say. The valve body might be gunked up. A shift kit wouldn't hurt. You could clean it at the same time. When you pull the valve body and let it drain, it drains most of the fluid out of the converter too. Than you can do the fluid, filter, and valve body all at once.