Dodge Journey Rear Brake Rotor Size: How to Tell 305mm from 328mm
Two Rear Rotor Sizes, One Easy Way to Tell Them Apart
The Dodge Journey’s rear rotors come in two sizes: 305mm (roughly 12 inches) for the standard brake package, and 328mm (just under 12.9 inches) for the heavy-duty brake package. Order the wrong one and it won’t fit the caliper bracket. The tricky part is that both setups use single-piston rear calipers, so glancing at the back of the car won’t help you.
The answer is up front.
The Front Caliper Is the Tell
Standard-brake Journeys use a single-piston front caliper. Heavy-duty-brake Journeys use a dual-piston front caliper. The rear rotor size follows: 305mm pairs with the single-piston front, 328mm pairs with the dual-piston front.
Chrysler used the same logic on the minivan platforms of that era. If the vehicle has the upgraded front setup, the rear gets bigger rotors to match. The Journey shares that pattern.
How to Tell Single from Dual Piston at a Glance
Crouch down and look at the outboard face of a front caliper — the side facing away from the vehicle. A single-piston caliper has one round boss in the center where the piston sits. A dual-piston caliper has two side-by-side bosses. About 30 seconds with a flashlight, no tools needed.
Another quick check: count the bleed nipples. Single-piston calipers have one; dual-piston calipers have two, one per piston chamber.
Confirming the Right Part on RockAuto or Another Parts Site
Once you know your front caliper type, finding the correct rear rotor is simple. On RockAuto, pull up rear rotors for your Journey’s year and engine. Listings break out by brake package — options labeled with heavy duty brakes, without heavy duty brakes, with dual piston front calipers, or the diameter shown directly as 305mm or 328mm. Match the label to what you found up front and you have the right part.
Shopping somewhere that doesn’t filter by brake package? Check the specs for the rotor diameter. 305mm and 328mm differ by 23mm — more than an inch — so the number settles any ambiguity in the listing.
VIN Lookup
Can’t get under the car? Your VIN is another route. A Chrysler or Stellantis dealer can decode it to your original factory build spec, including whether the heavy-duty brake package was fitted at the plant. Some third-party VIN decoder sites carry this detail too, though coverage varies by service.
Measuring the Rotor Directly
If the rotor is still on the car, a tape measure across the outer disc face gives you the answer. The 23mm gap between 305mm and 328mm is easy to see. Measure the outer lip of the rotor, not across the center hat.
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