Automatic Transmission issues (1st Gen)

Hey guys,
Tacoma
Year : 1996
Mileage: 147 K
2.4liter/
Truck was not engaging into overdrive/bogging and was not going over 3k rpm. Got 2 opinions 1 from a family mechanic and the other by a truck specialist and sent it out to get tranny rebuilt.
Was shifting smoother than ever and like a dream for about 100 miles .


Back to no overdrive , bogging and stalling at stops and won’t go over 50 MPH(3k RPM).
Will have it towed to the shop (reputable and well know for work) (has 12,000 mile warranty)

Could it be something else?

 

Definitely sounds like a transmission issue - what did they do exactly when they rebuilt it? A faulty torque converter could cause most of the symptoms you’re describing. Sticking shift solenoids could also be a culprit. Has the transmission had regular fluid changes throughout its life? And I guess the first question should be, is the fluid level correct right now?

 

Rebuilding a trans isn't too hard with a proper rebuild kit. Maybe they missed something? I agree with drr, maybe something is still faulty that wasn't replaced...

 

Update:
Full Tranny Rebuild has been made including replaced T/C , Test drove with the mechanic, 20 minutes into drive O/D disengaged/ Solenoid was changed with new OEM.
truck ran like Shit again and was rev limiting at 3k, wouldn't go over 50 mph, and not responding to full throttle.
Airflow is normal.
After 30 minutes CEL turned off and car returned to normal idle and O/D engaged. Ran like a dream, and the shifts were crisp and clean.
then as it started bogging and disengaged O/D , revs limited and felt like I was back to square one.
Today was able to plug in OBD2. Check engine light is on, OBD2 says cannot connect to ECU.
Had to leave car at the Tranny shop. Being as I Paid and had the full Tranny rebuild the shop says will diagnose and try to figure out the issue.

I am led to believe this is a ECU issue.
NGK Iridium Spark Plugs and wires placed 6k miles ago.
Optima Yellow 34 top Placed 2 months ago.
Oil service done 1.5k miles ago.
No auxiliary appliances.





Does Anyone have a clue what this could be?

 

You know that’s what I thought at first, ( if PCM is another way to say or main component of the ECU)
Until I test drove it after the rebuild, those 20 minutes were incomparable to how the truck was before. The shifts weren’t lazy ( didn’t take forever to transition) and the truck felt a bit more responsive.
I was shown some of my old components and i was convinced that after 150k miles in my truck the rebuild wasn’t that far away. mind you I bought it with 142k
And a coworker told me the original owner was an old guy that was a painter and he would haul a loaded bed every time he saw him ( after the fact he saw me driving it) and that it was put to work.

I could say I have that piece of mind .
Am I happy about it? nah not it all
I wish I had the tools and the time and the sources ( dealer part plug) to have done it myself.

Do I blame the shop no,
I mostly blame myself out of ignorance because I run daily a phone OBD2 scanner to track the O2 sensors and my fuel rate ( being as I have a Header & cat leak) and I never had problems communicating to the ECU.

And when this first occurred the Transmitter wouldn’t connect to ECU (prompting connection was lost) and after 2 days of forum searching I was convinced it was the O/D solenoid, and felt my assumption was confirmed when my uncle said so as well(35+ years of body shop /engine rebuild/ tranny replacement) so I naturally trusted his gut.

But I didn’t think it would be ECU , because after driving a bit the first time the car went back to normal, with its usual shift points , O/D and regular idle / and the transmitter was reading everything fine then.

And as soon as the truck began to feel like it was running starved/ rev limit/ limp home at 50mph the transmitter wouldn’t connect. Very sluggish to say for a fact , the trucks grunt and are slow but are in no means slugs compared to 90s diesels / and it was more sluggish than those.

To my ignorant self The solenoid seemed like a good enough explanation and I didn’t think of it twice (I’m a fool) .

But now I feel certain to begin with it was ECU issues , and the tranny rebuild wasn’t needed exactly then and there but eventually in the coming 30k miles maybe it would’ve.
Now I want to see how this is going to go in regards to what the shop wants to charge for sourcing a refurbed ECU, because I’m looking at $170-350 at them.
And if I’m adventurous enough ill yard hop to find a low mileage one under 120k

But I’m not irate (I am Ifeeling incredibly ignorant and naive) because I plan on riding this truck out and making it a project as soon as I upgrade back up to a newer gen after my second gen was totaled (it was parked).



Whoever can teach me anything about this, or want to leave your two cents, just add in.

 

Check all the fuses and try to get the communication back at the dlc. Check the alternator output and make sure it's not dropping off 20 mins into the drive