Brake rotor size?

1997 TOYOTA 4RUNNER
309,000 MILES • 3.4L • V6 • 4WD • AUTOMATIC
Avatar
EMILIANOG19
  • MEMBER
  • 1 POST
So, for my vehicle listed above Limited, I ordered some rotors, and they were too small (297mm) and I see they also have the 319mm and they fit, but I want to know why they fit and why the other didn’t fit.
May 24, 2023 at 1:36 PM
Advertisement
Avatar
BRENDON S
  • ✓Experienced Mechanic
  • 653 POSTS
Hello EMILIANOG19,

The bolt pattern looks to be slightly different.

Outside Diameter (mm): 296mm
Bolt Pattern: 6 On 139.7mm

Outside Diameter (mm): 319mm
Bolt Pattern: 6 On 140mm

So, the first number is obvious the 6 stands for the number of studs, but the second number is the diameter of the circle the studs make.

Thank you,
Brendon
May 24, 2023 at 10:19 PM
Avatar
STRAILER
  • ✓Experienced Mechanic
  • 55,249 POSTS
The 319mm rotors usually require 16-inch or larger wheels to clear the larger calipers.

The 297mm rotors are for 4Runners with 15-inch wheels.

Feb 10, 2025 at 4:00 AM
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.
Ask a Free Question
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.