Torque Bind with Automatic transmissions pre 99

So my HX20 has become a problem child, and the auto has started to torque bind when turning slowly in carparks, driveways and such. I has only started 200km ago and happens on and off. It started when we went from a 205/60/15 to a 215/50/16, from reading around changing tire diameter can be the cause of this so i went back to the old wheels and tyres and its doing it now alot less but not completely gone. Main suspect is the centre diff solenoid just giving out but at the moment i dont want to me taking it all apart just to find it can be something alot simpler. So at the moment options are to check the TCU for faults see if that tell me anything or nothing. Change the ATF fluid (which isnt a silly idea anyway) add some auto additive for good measure and clean out the auto pan and filter for crap. And if that doesnt work look at replacing the solenoid in the centre diff.

Just putting this up here for anyone that has had this issue as i cant find an old thread about it at all. It does seem to happen to alot of subarus but only ones with higher kms.

Am i going the wrong way about this? Is there a easier fix?

only an issue with tires if you only changed one set as this can cause centre diff to have issues.

you can try the trick of doing tight circles first one way then the other to see if that "unbinds" it

also fit a FWD fuse and do the circles as this disables the centre diff which may also help

doctor tranny fixed it for now, will be doing atf flush on it next month