Is there any need to keep the front and rear tires the same on a 1998 4wd Chevy Tahoe?
This should have said
Tires–Front Rear 4wd
Yes, 4wd and AWD vehicles are fussy about tires and unless they are the same size and type, problems are sure to result…
Do you mean the size or the brand? The size…yes. The brand…no.
Difference is having mostly worn but still good tires on front and brand new ones on rear.
Would this hurt the transfer case?
It will bind up the entire drive-train if you put it in 4wd. As long as it’s in 2wd, no problem. You might get away with 4WD for a SHORT period on snow-pack or dirt. On pavement, there will be problems…
There are no regulations that require tires to be of any particular dimensions - even if indicated by “the size”. Physical dimensions can vary enough between brands to cause problems for AWD and 4X4’s.
So the general rule is AWD and 4X4’s need to have the same size, same make, same model, and same state of wear to be sure that the drivetrain will not be damaged.