Your Full Service Differential Repair Shop since 1982!
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Ring & Pinion Service Quality differential service, repair and performance... Guaranteed!
Traction Upgrades Get more grip with a Limited Slip Differential, Locking Differential or Spool. Our expert installation guarantees top performance.
Axle Shaft Upgrades Chromoly and Performance Axle shafts are much stronger than factory equipment for Street, Strip or Off Road!
Gear Ratio Changes Those big truck tires need a gear ratio change for proper performance. Ring & Pinion Service is the Sacramento area's most experienced differential shop. Call today for a quote on changing the gear ratio in your rig!

Differential Gear Calculators

Tire Diameter Calculator

You need to know your tire diameter in order to work with the RPM calculator relevant to gear ratio.

Tire specifications usually follow a three number format, such as 275/75R16, where 275 is the WIDTH of the tire tread in millimeters, 75 is the ASPECT (or percentage of tread width to yield the sidewall height), and 16 is the WHEEL diameter. Using the numbers in this example, you’ll get a tire height of 32.24″.

The calculated value should be used only as a guideline for RPM calculations. Quite often, if you measure your tire diameter from the ground to the top of the tire, it measures less than the calculated value. It may “round up” closer to the calculated value while in motion. Tires with identical specifications that are made by different manufacturers may also have different actual diameters.

Truck and off road tires may have a specification like 30×9.5R15, where 30 is the tire diameter, 9.50 is the tread width and 15 is the wheel diameter. You don’t need the tire diameter calculator in this case.

 

 

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RPM Calculator

Use the RPM calculator to determine what RPM your engine will run based on gear ratio, tire diameter, transmission and MPH. You can try various combinations to come up with an appropriate combination of ring and pinion gear ratio and tire diameter for your vehicle. The RPM calculator should be used as a guideline for comparative purposes only. Your vehicle will probably run at different RPM’s than those you calculate. See What gear ratio do I need in FAQ for a discussion on choosing a ratio.

 

 

Recommended Engine RPM @ Highway Speed
  • 4 cylinder: 2200 – 3200
  • V6 cylinder: 2000 – 3200
  • Small block: 1800 – 2800
  • Big block: 1800 – 2600
  • Diesel: 1600-2800

 

Find the ratio you want? Contact the Differential Repair experts at Ring & Pinion Service at (800) 787-8012 to schedule an appointment or us our handy Online Appointment Form.

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Gear Ratio Calculator

Enter the number of teeth on your ring and pinion gear set to find the gear ratio. Example: Ring Gear / Pinion Gear = Ratio

 

 

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Free Diagnosis

Ring & Pinions

Free Diagnosis & Free Estimates

At Ring & Pinion Service, we always offer free diagnosis and Free Repair Estimates. Most commonly, one of our differential experts will road test your vehicle (if possible) and give you an accurate diagnosis based on the symptoms and sounds that are present. We can then make recommendations for repair or upgrade of your differential, and provide you with an accurate repair estimate.

Contact the Ring & Pinion Service staff for more information or make an appointment!

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Products Available for the Following Axle Assemblies:

AMC:
  • AMC Model 20
  • AMC Model 35
TOYOTA:
  • Toyota 7.5”
  • Toyota 8”
  • Toyota Landcruiser
  • Toyota Tacoma
  • Toyota Tundra
CHRYSLER:
  • Chrysler 7.25”
  • Chrysler 8.25”
  • Chrysler 8.75”
  • Chrysler 9.25” Rear
  • Chrysler 9.25” Front
  • Chrysler 10.5”
  • Chrysler 11.5”
DANA SPICER:
  • Dana 30
  • Dana 35
  • Dana 44
  • Dana 50
  • Dana 60
  • Dana 70
  • Dana 80
FORD:
  • Ford 7.5”
  • Ford 8”
  • Ford 8.8”
  • Ford 9”
  • Ford 9.75”
  • Ford 10.25”
  • Ford 10.5”
GM:
  • GM 55 Passenger
  • GM 55 Truck
  • GM Corvette
  • GM 7.25” Front Differential
  • GM 7.5” and 7.625”
  • GM 8”
  • GM 8.2”, GM 8.25” Front Differential
 
  • GM Camaro, Pontiac G8, GTO
  • GM 10 Bolt 8.5” and 8.625”
  • GM 12 Bolt Passenger
  • GM 12 Bolt Truck
  • GM 9.25” Front Differential
  • GM 14 Bolt 9.5”
  • GM 14 Bolt 10.5”

The Best Ring & Pinion Service in Greater Sacramento and Outlying Areas

Sacramento | Rancho Cordova| Carmichael | Fair Oaks | Orangevale |Citrus Heights | North Highlands | Rio Linda | West Sacramento | Folsom | Elk Grove | Roseville
Rocklin | El Dorado Hills | Loomis | Woodland | Davis | Placerville | Auburn | Lincoln | Marysville | Yuba City | Vacaville | Fairfield | Lake Tahoe Area

Contact Info

  • Ring & Pinion Service
  • 2429 Mercantile Drive
  • Rancho Cordova, CA 95742
  • Toll Free: 800-787-8012
  • Tel: 916-635-9665
  • Open 8am - 5pm M-F
    (Closed 12-1)
 
Ring & Pinion service provides quality professional differential repair and maintenance for Ford, Chevrolet, Chrysler, GM, AMC, Jeep and Toyota Vehicles. If you need a rear end specialist, look no further. Call Ring & Pinion Service for Quality Service, guaranteed!

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West Coast Differentials, Inc., Differentials - Automobile, Rancho Cordova, CA