91 Honda Auto trans

247k miles
We now have the third transmission in the car and it still does not shift into over-drive-4th. Odds seem poor that all 3 were actually bad.
What now?

Yes, odds are something else is going on. When did 1st trans replacement occur? 2nd, and then 3rd? Work done by same garage or different garages? Your problem is the torque converter itself, or the controls telling the torque converter what to do. Does you Honda have an overdrive “on/off” switch on or near the shifter?

The trans was replaced and had the same problem, it would not stay in the high gear at highway speeds. The OD switch on or not, it did not matter. The indicator light went on and off.
We took the car to another guy who was going to check it, who didn’t do anything.
The car has rudimentary computer check that does the flashing light thing. It said the trans was not working correctly.
The scrapyard by mistake shipped two transmissions so I had the mechaninc put it in. It works worse than the first one, it never goes into high gear.
$1000 in labor and $500 for the trans and still got squat.

Time to go to a REAL trans guy, not just a mechanic… It could be a few things, but with out more info we cant tell. Also it can be that since all these units are used that you did get three bad units…

I went to a real trans guy (aamco) who said he could put in a used trans for $2000. A mechanic said the same and we got a scrapyard trans.
The fact that three different transmissions do the same thing means it is probably not the trans but somewthing that stayed with the car for all three.
In online research since this morning I have found that the TCU, trans control computer, is probably bad. I am a bit pissed that my two mechanics did not do this research before swapping the trans.
For $2000, aamco would have just popped in a TCU and still end up ahead.
$80 online to buy one

After the first tranny swap didn’t solve the problem, why didn’t you go back to the mechanic and get satisfaction from him? If he didn’t fix the problem, he should either have refunded at least some of your money, or gone back and fixed it properly.

The mechanic replaced the transmission, he did not guarantee that it was a good transmission.
I do indeed need a better mechanic, one who can accurately diagnose the problem and not wait for me to tell him what is required next or ask him if he tried this or that.

The follow up on this trans problem, I got the used trans computer online and plugged it in and the thing now works fine. One trans shop, three mechanics did not find what I did on the internet in about 15 minutes. I found clear instructions on how to fix the computer by replacing a resistor and a capacitor but am not skilled in soldering on a circuit board. I bought one for $50 and it is a done deal. This is such a common problem that I suspect that the AAmco shop knew it as did the parts yard that sold me the transmission.

It’s a 21 year old car…There are over 250 makes and models of cars sold in the united states. Over 21 years, that’s 5200 different models of cars to keep track of. That’s well beyond the pay grade of most car mechanics…When confronted with a 21 year old car with 247K miles on it, transmission not shifting properly, the only mechanics who might have diagnosed this correctly would be Honda transmission specialists…

Nomatch1 wrote:

I went to a real trans guy (aamco) …

You might want to be careful with such a trust.
Caddyman’s summary of the situation is very well stated.