[SpeZ]

Hey guys,

with the 10l90 in my ZL1 I encountered already a few misshifts. It is very rare but usually happens at like 50 mph at WOT. After it shifts, it rev limits at like 4500 rpm and does nothing for few seconds.
Last time in that situtation I wanted to de escalate it and wanted to upshift once, then it actually downshift.

Sometimes at WOT shifts does not feel smooth and rarely it takes a little longer.
Overall it does not feel horrible, but I bet it wasn't like that when it was new.

Really bothered and already looking for upgrades to make sure the trans lasts. I can't really see any increase of torque converter slip nor trans slip with hptuners.

I track few times in a year, but also do frequent fluid changes strictly according to the instructions.
Since I have a 2019 model which got build in 10/2018 I wonder what the difference is on the 2020+ 10l90 transmissions.
18k miles mileage and 800 hp crank.

Maybe upgrading the valve body? I heard the newer 10l90 are more reliable and shift smoother.
Also considering upgrading the frictions plates with raybestos. Are they any good?

For now, my next step will be a trans tune.

[Patriot Motorsports USA]

Which Fluid are you using? I would HIGHLY recommend switching to the Amsoil ULV if you have not been using quality ATF. I have 32K miles with 14K on track with zero transmission issues. I just relocated my TransHX from the flat area to the passenger side Aux and upgraded the lines to -8AN to increase flow for cooling. HUGE difference!!

[SpeZ]

I've been using the oem fluid all the time. It is very cheap.
But next time I will use a quality fluid like Amsoil.

Since you own a 2021 model, you have a gen2 10l90 with couple of small changes.
I read that the newer 10l90 use better friction materials and even the valve body is different. Smoother shifts with better software in terms of adaptive learning as well.

[KingLT1]

It needs a good trans tune. The A8's and older A10's perform better all around with good tune.