Hello!
I have a 1994 Ford Ranger 4.0 L 4X4 with the A4LD automatic transmission. I recently have a full tranny rebuild done at a local shop, and ever since I've had some strange symptoms.
When I go to accelerate, I need to bring the rpm up to 2700+ just to keep up with normal traffic. If I floor the gas I can still make the tires squeak, but the acceleration seems quite a bit weaker than what I remember before I had the rebuild done.

I performed a stall speed test by holding down the brake and stepping on the gas, and the rpm ran up to 3100. Is that in the normal range for the stock torque converter? I've found a ton of different numbers online for stall speed ranging from 1800 up to 3200, and I'm not sure which is correct.

The other symptom I have is a shudder around 1800 rpm in first gear, basically as I am getting going off of a light.

Any advice or ideas would be much appreciated!

 

the converter is locking up too soon

wrong check ball springs in the valve body

 

You have an A4LD trans in a '94(last year), check the 3 wire connector on the trans.

Center wire should have 12volts with key on.
The other 2 wires are Grounds controlled by the computer to activate solenoids in the trans
One is TCC(torque converter control), computer locks TC when vehicle is moving, to give better acceleration and MPG.
Other is 3-4 shift control, Overdrive

Google: ford a4ld wiring image
To see what it looks like

 

Thank you for the advice. I brought the truck back to the shop with the suggestions of looking at the wiring and the valve body. They came back saying they still don't feel that anything is wrong, but they said they would like to try replacing the torque converter under warranty to see if that resolves the issue with the acceleration.

The other symptom I noticed was that the rpm does not always drop when the transmission changes gears. I hear the tranny shift, but the rpm stays put at 2100 rpm (or thereabouts) based on what I see on the tach. Is this even possible? Can a transmission change gears without a drop in rpm?

If it is possible, would a faulty torque converter be the cause?

 

NO! that year of transmission , it is the valve body is what controls the shifting of gears

the computer simply locks the torque converter when the vehicle reaches a certain speed ( hwy speed )

certain weights of springs and check ***** , when the atf fluid reaches a set flow level , 1 check ball closes and another opens .

 

Thanks for the reply!
So, when you say "NO", do you mean the tranny cannot shift without a drop in RPM, or that the torque converter is not the cause?

 

you would have to speak with a transmission expert about that

the A4LD was one of the 1st automatic transmissions that had a computer controlled torque converter lockup feature

 

The shop ended up replacing the torque converter under warranty. The acceleration issues I was having are now resolved! My truck accelerates the way it used to now. Not sure if it was a faulty torque converter or if they installed the wrong one, but at least it is fixed now.

 

Probably faulty torque converter.
"New" no longer means "it works"
"new" now means "never tested, but we will warranty it"

Thanks for posting the update