Transmission help please, shifting out of gear on upshift no CEL

Hello, i have an 2013 Tundra 4x4 with 93k miles. I have been towing about 8k on the weekends at least once a month.
My transmission is starting to act up. After driving a few miles, engine and trans is up to norm temps. Then i will get a random issue where going from 2 to 3rd gear (most of the time not higher gears) it comes out of gear i believe on upshifting and then my foot is on the gas for about 3 seconds before it reengages and rpms come back up.
No hard shifting, jerking, shaking or anything like that happens. Just comes out of gear seems like. I took it to the dealership to do a transmission drain and refill. But still having same issue. Slowly getting more problematic.
Need help because i have to move my camper out of storage soon. Any advice is appreciated. Im mechanically inclined just not in transmissions.

 

Hmm. Do you have cruise control on at any point in there? What RPMs are you sitting at when it shifts like so?

I didn't realize the sensitivity of cruise on this truck, and so the first time I towed a couple thousand lbs, it freaked me out by dumping the RPMs and turning off cruise on the way up steeper inclines. Quick forum search and I found out just not to use cruise towing, and never had problems again.

 

No cruise control, this is happening without towing but scared to tow right now till fixed. Its not a constant issue, starts happeing after a few miles 5+ usually.

 

next time let go of the gas, and see if it engage right away, or change the atf, but sounds like it's slipping

 

Atf was changed today from the dealership. It does reengage after 3 seconds or so and i typically will let go of gas when rpms are not coming up. Strange issue.

 

I may have missed it, but is it a 4.6 or 5.7? Is it a tow package from factory or aftermarket?
If you're driving in manumatic it would be easier to hold it on 3rd or 4th gear. Are you driving on inclines or is it flat land? There were some earlier complaints about the transmission hunting for gears in straight automatic or 'D'.
You may have a performace D stuck off pending code P2714 if I remember correctly which may mean you lost 2nd gear electronically and the transmission is jumping from 3 to 1 and back to 3 which leave some hessitation in between shifts.

 

In line w/what @blackdemon_tt is saying... I'd think that the dealer would have put a code reader on it... but just in case they didn't or if at the time it was in, it wasn't throwing any codes, I'd start there.

Most of the readers will offer 2 or 3 scan levels: 1: CIL Only 2: common dash lights 3: all systems

So, get a decent code reader on it and run a comprehensive scan of all systems (the scan should take several minutes to complete).

Also, if I'm understanding your post, it seems like your RPS are coming down 'when it's hunting'... If this is the case, it's possible that you have a faulty TPS (throttle position sensor); which could cause the transmission to behave inappropriately because it thinks your gas foot is doing something that it really isn't... just something else to consider.

 

My apology its a 5.7.
Factory tow package.
Flat lands.
I havent done tow mode(which im curious if that will help it shift into the gear)
I havent tried sequential shift mode yet.
Good info ty

 

I didnt tell the dealership about the issue, i have trust issues when the problem isnt consistent. Didnt want them to just throw parts at it hoping for a fix. But i see what you mean. Ty!

 

Understand the trust issue w/the dealers these days. After you've sorted through the code issue, if you need to push further w/professional help, I'd recommend finding a good transmission shop that you can trust. Service, diagnostics and repairs are generally cheaper and more specialized if you can find a good one.

You could even try to do a post on the forum asking for recommendations for a good transmission shop in your area by referencing your zip or major metro area if you're near one.

 

I got a bluedriver obd2 and can scan all systems.. It was convenient for me but there are cheaper options with similar capabilities which can help you. Other options try autozone or oreillys for diagnostics, they just wont erase the codes.

 

Update: transmission shop said its engine related. Ill be chasing it down and reporting back. I do have a brake light cel code. I did a recent brake light led light upgrade and im having an issue with one of the lights. Im going to reset ecu, clean the maf sensor, clean throttle body, fuel treatment then see if I still get the issue.