Two different sized tires on front wheels

Hello all, I have a 2013 tundra rock warrior. Stock rock warrior wheels with Falken 285/75/17. I got a flat tire a couple weeks ago on my front passenger side and have been driving around with the spare on (the shop I go to has been super busy and wouldnt return my calls but thats another story).

The spare is a brand new falken 285/75/17 with full tread and the rest of the tires have maybe 1/4 tread left on them so there might be around an inch difference more or less in overall diameter.

I was unaware that it is bad practice to run different sized tires because it can mess with the differential is how i understand it. Would that still apply if its on the front instead of the rear and the 4wd isnt engaged? Would the tires just be free spinning anyways? Im not super knowledgeable in this area.. Whats the likelihood that Ive trashed my front differential or 4wd components, Thanks a lot for any help

 

In the future if you have 5 tires, I've always practiced this maintenance; When rotating tires I've always rotated that 5th into the mix. Keeps all tires including spare same tread thinkness more or less. Lots of opinions on this one out there but as @ColoradoTJ said, you're fine they way you are now.

 

It hurts nothing when in 2 wheel drive.

You will get extra loud shift noise when you disengage the transfer case on dry pavement.

 

Ok awesome. the mechanic i talked to made me nervous, thinkin my front differential and transfer case were gonna be in pieces lol. And mixing the spare into the rotation is a good idea i didnt think about that. Thanks for a lot for yalls help!

 

The differential doesn't care. The speed sensors that measure the speed of each wheel could get pissy. Because the one wheel is spinning at a different speed than the others, the computer could think the odd wheel is spinning.

Not gonna hurt anything, but should be noted.