AC60F VERY rough 3-4 shift over 6000rpm

My truck has been doing this for as long as I’ve had it, and it’s not showing any signs of wear as far as I can tell. The 3-4 shift is 100% fine until over 6000rpm ish. Telling me I shouldn’t run the truck super hard won’t help me, I just want to know what could be causing this. Not a big issue it seems like, just kinda odd.
https://youtube.com/shorts/JmLjYHDPIS4?si=rute_d_jLO0NLFta
In the first clip of this video is the rough shift over 6000, 2nd clip is just a normal shift.
The harsh shift feels like the car is getting rear ended. It’s an insanely violent slam, I think you can hear the tires chirp in the video. Like I said though, no signs of wear and no metal in the trans oil.

 

That don't sound good or normal. My wild guess would be to check your aftermarket gears, tune, drive shaft, u-joints and trans fluid level.

 

I’m gonna rule the gears out because it did it on the stock 3.91s or whatever they are. Also kinda ruling tune out because it’s done it on KDmax and Yotawerx. I just had the fluid changed and there was no metal in the oil, so I’m really lost on this. It’s showing 0 signs of damage but it feels like it’s getting hit by a semi truck every time it does it.. guess I’ll just have to avoid that shift. Whatever

 

That don’t make sense. Strange issue. I’m stock with OTT and factory gears. I’ve done a number of 6.5k shifts without that concerning noise.

Other thing is how it’s intermittent. Maybe something in your torque converter?

Did you go out and see if the driveshaft has any play in it? Also the U-joints?

Maybe @Vlady or @TnShooter might have some ideas.

 

Haven’t checked the driveshaft yet, gonna do that tomorrow. I’m really confused though because it’s exclusively on the 3-4 shift over 6000. I can shift into any other gear over 6000rpm no problem, I can shift at 7k in 1st and 2nd. Have you tried a 3-4 shift in manual mode bringing it up to 7k? I’d really like to know if another truck does this. You might have to go pretty fast to hit that shift if you’re on big tires though. I’m pretty sure when I was on stock gears and 33s i made that shift at 80 or 90 something mph.

 

I would check if you are not hitting a fuel cutoff rpms, speed governor, etc.
Check tranny output shaft rpms during these shifts.

 

Fuel cutoff is 7000rpm. Speed limiter is tuned out. Just checked the driveshaft and all is well, so I really have no idea.

 

I would still datalog parameters and go from there. Tranny output shaft rpms are used in shifting schedule tables. So if you are tuned, have them look at specific region of operation that cause the issue.

 

Holy shit you can make these trucks rev up to 7k?

 

Should smooth out at 8k rpm

 

Yeah the 2GR is a very rev happy motor. I think the Camrys and IS350s stock rev limiter is at 7000. RR racing tune bumps it to 7400. More than safe to run the motor this high up, trans doesn’t seem to love it tho

 

How about 9,000? 10,000? What’s stopping us??