Well this isn't a question but actually a story from yesterday. First I have to pretext it with some other particulars.
2004 silverado regular cab 4wd, 5.3 turbocharged. He Crunched a FTI street 3200 convertor stalling on it too hard, pulled the trans apart (I built it two years ago) and cleaned it all out and replaced the frictions even though there was no signs of slippage or wear. Trans is completely built (by me) sonnax billet input and output, billet reaction shaft, 4l79 drum, heavy duty sprags, billet over run bell etc etc. Then we put a single disc yank 3800 in it built to his specs. We had this built with the notion he wasn't towing, but he decided to tow his side by side he WAS selling, 2.5 hours away. He badly overheated it and burned it up. Pulled trans. Convertor was destroyed. Only thing I found with the trans was the input shaft was able to be pulled in and out of the input drum by about 1/2". Lucky I caught that and to be honest, but I always pull up on the input shaft to make sure it has some play. It also looked like the shaft was sticking out too far. Lightly tapped with a rubber hammer, shaft went in about 1/2. Well ****.

I took it all back apart and loctite 638 it back in. I did not install the shaft initially and it looks like it barely had any loctite on it originally. It came installed in the drum so I trusted it. Not saying this caused the convertor to fail but likely it did not, none of the clutches had any sign of slippage. I cleaned it out as good as I could, over a case of brake cleaner along with using mu parts washer. I flushed, sprayed and flushed and sprayed. I pressure flushed the cooling lines with two cans of brake cleaner. Whole valve body disassembled and cleaned. I left no stones unturned. Put trans back in, works perfect. At least for about 5 days. Then on tuesday (today is thursday as I type this) he calls me and says it didn't want to take off in first gear, was leaving in second gear. I told him put it in manual first and try it, that worked, it shifted all gears then. It onlt did it s couple times and started working normal again. Odd I thought to myself, mustve been some trash I missed?

So, yesterday he calls me and says on the way to work it started acting up again, but this time manual first did not work and it was trying to leave in third but he could put in in manual second. then it started trying to leave in 4th. Manually shifting 2,3,4 got him to work and back home. I pick up some solenoids and a manifold pressure plate on the way home from my supplier. Originally I told him to drain the fluid and pull the pan and I'll pull the valve body off, clean it and put new solenoids in and a pressure plate. But something told me to hold off on that. I get home, grab my computer and cable, UNPLUG his aeroforce gauge from the obd2 port (this has me wondering if it was causing this) and when I plug my laptop in, key forward and truck not running, scanner on, I notice its in third gear. I crank the truck, it then goes to 1st gear. I back up and go forward....its definitely in first. So I back out the driveway and it now has first. Drives like normal. Went rode around, never skipped a beat. So he rode around last night for a while, nothing. Went to work this morning and no issues. Is that not weird or not? Just thought I'd share this. I did end up reflashing the computer after we rode around just in case it was a glitch in that.

 

.....very interesting

 

NOTE with a 3000 stall , A false code PO757 can be set intermediately causing Limp mode as you described. This may be random and anoying and is NOT a Trans or solenoid issue.
The PCM seems the slip of the converter as a no shift from 1-2 and then set code for shift solenoid B stuck.
I always suggest this code be tuned out of any car or truck running a 2600 or higher stall and most certainly with high geared 2.73 to 3.42 ratio cars and trucks .
Hope this helps . But sounds like what you are getting. Also sending PM

 

Thanks Frank, I just replied to your message. More on that for the people reading in a minute......
Well we've had a 3200 in it for over two years. I'm going to check my tune this evening as I don't remember if I turned that off... But I am aware of it and I USUALLY turn it off. However, one would think if I didn't it would have reared its ugly head with the yank as it was WAAAAAY looser than the circle D. Quite honestly, I'm SUPER impressed with how stock feeling the circle D is in his truck. I now want one in my car. Badly, but right now I cannot afford it. Maybe later.

Now I'll mention your message. I'm sure other people who read my post are thinking the same thing you are. You pointed out that loctite holding a loose shaft in the input drum is a bad idea (the jist of it anyways). I agree 100%. (thanks for privately pointing that out) I didn't want to do that but I really had no choice. Kid was out of money and didn't have $600 for another one after just spending $900 on the yank, then $1400 for the circle D plus the other stuff I did to the trans while it was apart. He's in pretty deep at this point. I'll tell you though, my suggestion to his was to take my stock converter from my GTO I've been saving (nothing wrong with it) and put that in the trans before buying the yank, when the 3200 failed, just to get him going and save up and do a 4l80e and sell the built 60e to someone without a turbo lol. He decided against that although he could have at this point considering the amount of money we've put in it.
Of notable mention, I have done this before. A kid my son is friends with has a trans am with a built motor and a 60e. The guy who built the trans had to fix it 3 times. He brought it to me. His shaft fell out of the input drum when I went to press it out. I loctite 638 the shaft. Been over a year and before the trans would last a month then burn up. knock on wood! He does beat the **** out of it too. Thats all I got. I took a chance and we will see how it goes. lol

 

I have honestly over the years seen cars go and go and never have the issue then boom they do, Also I would kill p0751 it can also cause same issue thinking you are having a 2nd gear start.
I have run into many times and the most common is "Well I have been driving it a year and just now started happening" I have no explanation for that. But seen it many a time over the years.
Also note if you did the overun mod, It will change he way the PCM sees gears at coast and could also affect whether or not the code sets .

 

I didn't do the over run mod (extra friction) But years ago I did do the sonnax HD 2-3 shift valve. I told my son to remind me this evening to check and make sure that code is disabled. Thanks for reminding me of that!

 

yes, very.

 

I have no idea if the gauges had anything to do with your issue or not, but those aeroforce gauges ARE capable of 2 way communication, and they do glitch and burn out over time. I have seen 3 sets in 3 different vehicles work for years and eventually burn out. It appears to be the same component that burns up in all of them. I have 1 of a set of 2 in my GTO that is still working, but the other burned out a few years ago. They were approximately 2005-6 vintage, so they have quite a few years of use on them.

 

Any update on this?