07 4L60E trans question

A couple of weeks ago during a 6 hour round trip excursion my CEL came on at the very beginning of my drive because my converter did not lock up. P0700 & P0741. So, I limped there and home at 50 mph for the 6 hour drive, I was kinda freaked out that my trans would explodebut, made it home without issue.
Dropped the pan and replaced my TCC transmission control solenoid and filter. Put the same fluid back in and went for a few little trips and it seemed fine even though I babied it.
Had to take another 6 hour trip and it locked up and everything seemed fine again, RPMs dropped like normal, and it drove fine. Then randomly it unlocked and locked up again but the RPMs never dropped. When I drive at 60mph its usually around 1800rpm. This time it was 60mph and it was around 2200/2300rpm.
After this trip, no codes, nothing. The only difference is I burned up some gas.

I was hoping to get at least 300k out my 4l60e and not have to drop $4k+ for a reman locally. Or close to that for an aftermarket + install.
Has anyone else experienced this?
What could be the problem?
Could it be my converter? It's an FTI 2800/3000 billet stall.

Thanks

@NickTransmissions might have some thoughts on this.

I do have one question….why did you put the same fluid back in j stead of taking the opportunity to put fresh fluid in?

I put the same fluid back in because I had it serviced a couple of years ago and hadn't put that many miles on it. It didn't look bad.
I was going to put fresh but a buddy recommended to keep the fluid and see what happens. From my understanding new fluid can cause slippage.

992dr said:

I put the same fluid back in because I had it serviced a couple of years ago and hadn't put that many miles on it. It didn't look bad.
I was going to put fresh but a buddy recommended to keep the fluid and see what happens. From my understanding new fluid can cause slippage.

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Gotcha. Everyone has their beliefs and ways of doing things and that’s fine.

I myself never bought into the whole new transmission fluid causes issues in old transmissions and I have never put any fluid that came out of my vehicle back in. No fluid is expensive enough for me to try and save money by reusing it.

wjburken said:

Gotcha. Everyone has their beliefs and ways of doing things and that’s fine.

I myself never bought into the whole new transmission fluid causes issues in old transmissions and I have never put any fluid that came out of my vehicle back in. No fluid is expensive enough for me to try and save money by reusing it.

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This is the first time doing it. I didn't feel good doing it but since I had to drive so far, I was more concerned with longevity. I will be replacing the fluid with new.

992dr said:

From my understanding new fluid can cause slippage.

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How exactly did you acquire this "understanding" about new fluid?

NickTransmissions said:

How exactly did you acquire this "understanding" about new fluid?

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My friend had brought it up, otherwise hearsay.
This was the first time re-using fluids. My main concern was making the drive. I will be replacing the fluid with new.
I'm just trying to get more experienced diagnosis because everyone around here wants to replace it without attempting to even look at it.

992dr said:

My friend had brought it up, otherwise hearsay.
This was the first time re-using fluids. My main concern was making the drive. I will be replacing the fluid with new.
I'm just trying to get more experienced diagnosis because everyone around here wants to replace it without attempting to even look at it.

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I'd listen to your friend less; a lot less - at least when it comes to transmissions.

Do you have a bidirectional scan tool?

Unfortunately, I do not have a scan tool.

992dr said:

Unfortunately, I do not have a scan tool.

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Fti is supposed to be quality stuff I’ve got a 4wd 4l60 with 175k miles I’ll let you get cheap but you would have to pull it out I could help you do that if need be but it sounds like something else maybe electrical in the computer or the sensors that’s a weird issue.
I always had Jamie Parker in havelock to tune my stuff and he has always had the transmission tuned dialed in perfectly but your right nobody around us wants to mess with transmissions there is one fella in James city Newbern way that is supposed to be good I had terrible luck with Ammco recently so avoid them IMO
Performabuilt is supposed to be pretty good built transmissions