Long story short, I have 2 different brands of tires on the front and rear axles (same brand per axle). All are 265/70/17. I measured them with the wheels off the truck and they were less than 1/4" difference in diameter between the front and rears. Now when I put them on the truck and measure, they are between 1/4" and 1/2" inch different. I pumped the lower ones up a little more than the other axle to try and even it out but it didn't help.

Will this cause an issue if I only use 4wd while on ice where all tires can slip? Don't want to blow up the transfer case. I know it's not ideal but it's what I have to do for at least 3 months when I can put my summer tires on and find matching tires for this set.

It's a 2002 F150 5.4 with the electronic 4x4.

 

Yes, you should be fine. The reason you get a different measurement when mounted on the truck is "squish" caused by the weight difference between the front and rear of the truck.

 

Lol, yes I realize why they are different once on the truck.

Wondering what the acceptable amount of difference is, if any? There has to be a certain amount of play in the driveline to offset different diameter tires. Maybe less than 3%?