line.gif (831 bytes)
1967 Oldsmobile Differential
Identification and Ratios
 line.gif (831 bytes)

QuikFact: The corporate GM terms "10-bolt" and "12-bolt" actually refer to the number of bolts used to fasten the ring gear to the carrier flange, but it also corresponds to the number of bolts fastening the rear inspection plate, which permits easy identification.
bluspacr.jpg (522 bytes)
The differential ratio code letters (1/4" high) are usually stamped on the right rear inboard side of the axle tube housing, though they can also be on the backside of the axle tube. Letters for both standard and Anti-Spin differentials, indicating corresponding ratio for each series, are shown in the following table:
bluspacr.jpg (522 bytes)

Fisher Body Shell Designation Number
To find the correct ratio in the charts below for your vehicle, you need to look at your vehicle's Vehicle Identification Number (V.I.N.) and determine your vehicle's Fisher Body Shell Designation Number . The 2nd and 3rd numbers of the V.I.N. are what you're looking for. Match up your number with the types listed below:
  • 33 Series - Standard F-85 w/ L-6 engine
  • 34 Series - Standard F-85 w/ V-8 engine
  • 35 Series - Deluxe F-85 w/ L-6 engine
  • 36 series - Deluxe F-85 w/ V-8 engine
  • 38 series - Cutlass F-85 w/ V-8 engine
.

Code Letters
Standard Type Differential

Code Letters
Anti-Spin Type Differential

Series

 Gear Ratio No. Gear Teeth Std. Equp. With J-52 With J-56 With Y-75 With J-56 & Y-75 Std. Equip. With J-52 With J-56 With   J-75 With J-56 & Y-75
3300 thru 3800 (ex. station wagons) 2.41 41:17 SS SU ST - - TA TS TB - -
2.78 39:14 SA S2 SK - - SB S3 SL - -
3.08 40:13 SC S4 SQ - - SD S5 SR - -
3.23 42:13 SE S6 SV - - SF S7 SW - -
3.42 41:12 TL S8 TP - - TM S9 TQ - -
3.91 43:11 TN T2 TU - - TO T3 TV - -
Station Wagons (3455 - 65, 3855 - 65) 3.08 40:13 SG T4 SG - - SN T5 SH - -
3.23 42:13 SO T6 TC - - SP T7 TD - -

Back Home

Axle Ratios with 3-Speed Manual Transmissions
Axle Ratios (to-1) Engine 2.78 3.08 3.23 3.42 3.56 3.90
Cutlass Supreme 350-hp 4-4-2 Rocket V-8 (L78) (A) - G90 Std. G92 (B) G93 G94 (C)
320-hp Jetfire Rocket V-8 H.C. (Std.) (L74) - G90 Std. G92 (B) G93 G94 (C)
310-hp Jetfire Rocket V-8 (L73) - G90 Std. G92 (B) G93 G94 (C)
300-hp Rocket 400 (L66) (A) - - - - - -
Cutlass, F-85 320-hp Jetfire Rocket V-8 H.C. (L74) - G90 Std. - - G94 (C)
310-hp Jetfire Rocket V-8 (L73) - G90 Std. - - G94 (C)
250-hp Jetfire Rocket V-8 (Std.) - Std. G91 - - -
155-hp Action-Line 6 (Std.) Std. G90 G91 - - -
(A) Available for Sports Coupe, Holiday Coupe and Convertible
(B) Heavy-duty Performance Rear Axle Package. Includes heavy-duty shafts, bearings and differential gears available at extra cost.
(C) Not available with Air Conditioner (C60)
Axle Ratios with Wide Ratio 4-Speed Manual Transmissions
. Engine 3.08 3.23 3.42 3.55
Cutlass Supreme 350-hp 4-4-2 Rocket V-8 (L78) (A) - G91 G92 (B) Std.
320-hp Jetfire Rocket V-8 H.C. (Std.) (L74) G90 Std. G92 (B) G93
310-hp Jetfire Rocket V-8 (L73) G90 Std G92 (B) G93
300-hp Rocket 400 (L66) (A) - - - -
Cutlass, F-85 320-hp Jetfire Rocket V-8 H.C. (L74) Std. G91 G92 (B) G93
310-hp Jetfire Rocket V-8 (L73) Std. G91 G92 (B) G93
250-hp Jetfire Rocket V-8 (Std.) Std. G91 G92 (B) G93
155-hp Action-Line 6 (Std.) Std. G91 - -
(A) Available for Sports Coupe, Holiday Coupe and Convertible
(B) Heavy-duty Performance Rear Axle Package. Includes heavy-duty shafts, bearings and differential gears available at extra cost.
Axle Ratios with Special Ratio 4-Speed Manual Transmissions
  . Engine 3.42 3.55 3.90 3.91
Cutlass Supreme 350-hp 4-4-2 Rocket V-8 (L78) (A) G92 (B) G93 (D) Std. (C) G88 (B,C)
320-hp Jetfire Rocket V-8 H.C. (Std.) (L74) G92 (B) G93 (D) Std. (C) G88 (B,C)
310-hp Jetfire Rocket V-8 (L73) G92 (B) G93 (D) Std. (C) G88 (B,C)
300-hp Rocket 400 (L66) (A) - - - -
Cutlass, F-85 320-hp Jetfire Rocket V-8 H.C. (L74) G92 (B) G93 (D) Std. (C) G88 (B,C)
310-hp Jetfire Rocket V-8 (L73) G92 (B) G93 (D) Std. (C) G88 (B,C)
250-hp Jetfire Rocket V-8 (Std.) G92 (B) G93 (D) Std. (C) G88 (B,C)
155-hp Action-Line 6 (Std.) - - - -
(A) Available for Sports Coupe, Holiday Coupe and Convertible
(B) Heavy-duty Performance Rear Axle Package. Includes heavy-duty shafts, bearings and differential gears available at extra cost.
(C) Not available with Air Conditioner (C60)
(D) Required with Air Conditioner (C60) or Heavy-Duty Engine Cooling Equipment (Y76)
Axle Ratios with Automatic Transmissions
  Engine 2.41 2.73 2.78 2.93 3.08 3.21 3.23 3.42 3.55 3.90 3.91
Cutlass Supreme 350-hp 4-4-2 Rocket V-8 (L78) (A) - - - - Std. - G91 G92 (B) G93 G94 (C) G88 (B,C)
320-hp Jetfire Rocket V-8 H.C. (Std.) (L74) - - G95 - Std. - G91 G92 (B) G93 G94 (C) G88 (B,C)
310-hp Jetfire Rocket V-8 (L73) - - G95 - Std. - G91 G92 (B) G93 G94 (C) G88 (B,C)
300-hp Rocket 400 (L66) (A) Std. - G95 - Std. - - - - - -
Cutlass, F-85 320-hp Jetfire Rocket V-8 H.C. (L74) - - G95 - Std. - G91 G92 (B) G93 G94 (C) G88 (B,C)
310-hp Jetfire Rocket V-8 (L73) - - G95 - Std. - G91 G92 (B) G93 G94 (C) G88 (B,C)
250-hp Jetfire Rocket V-8 (Std.) - - Std. - G90 - G91 G92 (B) G93 G94 (C) G88 (B,C)
155-hp Action-Line 6 (Std.) - - Std. - G90 - G91 - - - -
(A) Available for Sports Coupe, Holiday Coupe and Convertible
(B) Heavy-duty Performance Rear Axle Package. Includes heavy-duty shafts, bearings and differential gears available at extra cost.
(C) Not available with Air Conditioner (C60)
(D) Required with Air Conditioner (C60) or Heavy-Duty Engine Cooling Equipment (Y76)

Back to the top

Back Home
Tech Tips and Tricks

  • Here is how you can test your anti-spin carrier: Jack one wheel off the ground and put a torque wrench on one of that wheel's lugnuts. A new healthy anti-spin unit will take 100-125 ft/lbs to get the wheel to turn independently. If it takes less than about 40 ft/lbs, the unit is worn out and should be rebuilt.

  • Richmond Gear sells 3.91 ring and pinion sets for the '68-'70 "O" type axle and are built to install on the 3.08-3.23 carrier.

OLDSmobility.com Related Links

Back Home

Back to the top
| Home |
| My Personal Project - Photo Galleries | Updates/Journal | Sign My Guestbook | View My Guestbook |
| 1967 Specifications - Model ID | Product Specs | General Specs | Engine | Tune-up | Torque |
| Vintage Ads | Vintage Road Tests | Technical How-To's | Owner's Registry | Messageboard | Links |

line.gif (839 bytes)

Want to link to this site? Please use this banner.
OLDSmobility.com - The 1967 Olds Cutlass and 442 Resource

The correct URL for this website is http://www.OLDSmobility.com/)
For questions, comments or suggestions, please e-mail me.
All content on this site is © 1999-2008 by OLDSmobility.com/Project 442 Clone, unless otherwise noted.  All rights reserved.
This page last modified on February 15, 2003.