Wonky Convertor Lockup?

[Fordlover96]

Hey guys, what's up?

My 93 ATX just hit 89k the other day and has been running great. Hasn't really given me any real trouble in a long time. Other than a blew heater hose (again) and this transmission issue, the car has been flawless.

Now, this is the weirdest thing. Okay, how do I explain it.

When the car shifts into fourth gear (usually at 40) about 70% of the time, the torque convertor lockup will do some weird shit. It will lock up, RPMS drop, at around 35 and then when the transmission shifts into fourth it will disengage and then engage again. You can physically feel it in the car. RPMs will jump way up and then back down.

The reason I say its the lock up and not a slipping shift is because the other thing it does is at highway speeds. Doing about 70 if I push the gas about an inch, the RPMs will drop way down and the thing will pull. If I pull my foot up, but not completely off the gas, the lockup will pop out and the RPMs will jump way up. So just cruising the lockup isn't engaged.

The car never did any of these things up until a month ago.

Any ideas? I've swapped out the throttle position sensor and let the car sit without the battery disconnected over night. The later did help for a couple days then it returned right back to doing the weird thing.

 

[rubydist]

iirc, the tc unlocking when it first shifts into 4th is normal.

what do you mean by "about 70 if I push the gas about an inch, the RPMs will drop way down and..." ??

it is normal for the tc to unlock if you lift off (or nearly off) the throttle at highway speeds. that is how that had the pcm programmed.

 

[tommyturbo]

check for fault codes. ATX have fault codes also. As for the lock up, converter locks up in 3rd and then unlocks for the shift to 4th and then relocks. It will lock and unlock depending on load and throttle position during driving. If you press the gas at 70 the converter will unlock to allow the torque convert to do it's job, and once your speed and and throttle position stabilize after the speed you want is reached, it should relock again. The converter lock up is also modulated, meaning it is not just locked or unlocked, but it locks gradually via control from the solenoid pack in the valve body, like slipping a clutch. it's possible the converter is wearing out, and may feel like chatter as the lockup happens.

On my 95 ATX the converter will sometimes lock and unlock when the a/c cycles due to the added load and the computer compensation. I've also noticed that at very light throttle the car shifts into OD at around 40 or so, and when it tries to lock up it almost bogs the motor feeling more noticable. My super coupe does this too, must be a ford programming logic.

 

[Fordlover96]

iirc, the tc unlocking when it first shifts into 4th is normal.

what do you mean by "about 70 if I push the gas about an inch, the RPMs will drop way down and..." ??

I mean that anymore than light throttle, the convertor clutch will lock up and thus the RPM's will drop. After the decent push of the pedal, the lockup will pop out. What concerns me is that the lockup will pop out without my foot leaving the pedal. I swear the car never did this before. But idk.

I think I'm coming to the conclusion that the transmission is just slowly ******** the bed and there's nothing I can really do about it. hahahah