Tires: 99 Durango stock tires wont bead, stock tires, rim widths

Question
My girlfriend has a 99 durango that has 31x10.5x15's on it and
when I went to replace her tires with the stock 235/75/15's
the rims were too wide for the tires to bead.

Answer
Dear Robert,
Thank you for using AllExperts.
I'm wondering just how wide those rims are.  Each tire size has a range of 'rim widths' that it may be mounted on.  For example, 31x10.5R15 may be mounted on 7.0" through 9.0" rim width. P235/75R15 may be mounted on 6.0" through 8.0"  This is true regardless of the tire brand.
You can measure the rim width easily with a tape measure...measure on he inside between the rim flanges:
http://www.therangerstation.com/tech_library/images/wheels/wheelwidth.jpg
or
http://www.sl113.org/forums/uploaded/jeffc280sl/200711817130_rim%20width.jpg
It sounds like your rims might be wider than 8.0"

Let me know if I can be of further assistance.

DT

Note: As a volunteer on this site, I assist people with tire questions on my own time.  I this information has been helpful to you, please be sure to complete the rating section.  Thank you!