ATF issues when warm

Hi,

my ~70k kms PFL Legnum AT has started showing some concerning transmission behavior. Seems to be getting worse and collecting more issues as ambient temps increase toward summer.
All three of these things seem to only happen after warming up to a normal operating temp. Everything works fine when cold:

Symptom 1: Hard 1-2 shifts after driving awhile (at least 15-20 minutes) This was the only issue for awhile, a few months.
Symptom 2: Automatic upshifts from 2-3 hang sometimes. As in, it stays in gear when it should be upshifting based on speed and load. I believe when this happened, 2nd gear LED is maintained on cluster as well. When this occurs, switching to manual mode and upshifting works fine.
Symptom 3: Noticeable slipping of torque from a start in first gear. Not completely debilitating, but to the point where I.


I am not sure the background of the fluid or how old it is, to be honest I assumed it was changed when the engine was swapped before I got the car, but I'm realizing now if it isn't necessary to change fluid on a short block swap, they may not have done so.
Any of these issues ring a bell with anyone?

Thanks!

Your first port of call would be a full gearbox oil flush, not just a drain and refill but a full flush with good decent oil like Amsoil. This could take up to 14 litres of oil before it runs true clear colour IIRC. THose more knowledgable will be along to show.

I recall my low mileage Legnum when I first bought it had a tendency to slip slightly and then gear hang before eventually changing into gear with a 'slap'

A full flush with Amsoil sorted this out and went on to survive to this day!

All of these symptoms sounds like old or bad or incorrect fluid.

If you are not sure of the state of the fluid, get it changed to something you know is good and correct, I would strongly recommend Amsoil ATF, and be sure to perform a full flush https://www.clubvr4.com/forum/showth...box+oil+change