MODEL IDENTIFICATION
| Series (1) | Model |
|---|
| "C" | 2WD Pickup, Sierra & Suburban |
| "G" | (2) Van |
| "K" | 4WD Blazer, Pickup, Sierra, Suburban & Yukon |
| "L" | All-Wheel Drive (AWD) Astro & Safari |
| "M" | 2WD Astro & Safari |
| "P" | Commercial Van |
| "S" | 2WD Blazer, Jimmy, Pickup & Sonoma |
| "T" | Bravada, 4WD Blazer, Jimmy, Pickup & Sonoma |
| (1) Vehicle series is fifth character of VIN. (2) Includes Rally Van and Vandura. |
| (1) | Vehicle series is fifth character of VIN. |
| (2) | Includes Rally Van and Vandura. |
SAGINAW BUILT AXLES
Axle identification code for rear axles is stamped on forward surface of right axle tube, 3-5" outboard of carrier (6-8" on 20 and 30 Series trucks). Location of identification code for front axles is not available from manufacturer.
DANA BUILT AXLES
Identification code is stamped on rear surface of right axle tube. In addition, the 3-digit axle code appears on tape strip attached to outboard end of axle tube.
Note. Drive axles are balanced with pinion flange (acts as a harmonic member to reduce driveline vibration). If ring and pinion gear set, pinion flange assembly or pinion bearings need replacement, replace entire axle assembly using appropriate system-balanced service axle assembly.
| Application & Code | Ratio |
|---|
| 7.625" Ring Gear |
| USM, USN (1) , UTM (1) , UTL (1) | 3.23:1 |
| USR (1) , USP (1) , UTP (1) | 3.42:1 |
| UST (1) , UTS | 3.73:1 |
| (1) With positive traction, limited slip differential. |
| (1) | With positive traction, limited slip differential. |
ASTRO & SAFARI REAR AXLE RATIO IDENTIFICATION
| Application & Code | Ratio |
|---|
| 7.625" Ring Gear (ZYD) | 3.42:1 |
ASTRO & SAFARI FRONT AXLE RATIO IDENTIFICATION
| Application & Code | Ratio |
|---|
| 8.5" Ring Gear |
| UMJ (1) , XPD, XPH (1) . XPL | 3.08:1 |
| RYS, RYX (1) , UUT, XPF, XPJ (1) , XPM, XPP (1) , XR | 3.42:1 |
| UUU, UUW (1) , XPG, XPK (1) | 3.73:1 |
| 9.5" Ring Gear |
| RYA, RYF (1) , TXW, TXZ (1) | 3.42:1 |
| RYB, RYG (1) , TXX, TYA (1) | 3.73:1 |
| RYC, RYH (1) , SJA, TXY, TYB (1) | 4.10:1 |
| RYD, RYJ (1) | 4.56:1 |
| 10.5" Ring Gear |
| RYK, RYN (1) | 3.42:1 |
| RYL, RYP (1) , XYL, XZC | 3.73:1 |
| RYM, RYR (1) , XUD, XYM, XYY, XZA, YAL | 4.10:1 |
| XYN, XYR, XYZ, XZB | 4.56:1 |
| 11" Ring Gear |
| UXP, UXK, UXL | 4.63:1 |
| UXR | 5.13:1 |
| (1) With positive traction, limited slip differential. |
| (1) | With positive traction, limited slip differential. |
"C" SERIES REAR AXLE RATIO IDENTIFICATION
| Application & Code | Ratio |
|---|
| 10.5" Ring Gear |
| AYA, AZA | 3.42:1 |
| CNB, XZK, XZL, YAK, YAN, YAX YBB, YBF, YBJ, YBM | 3.73:1 |
| XZM, XZN, YAL, YAS, YAT (1) , YAY, YAZ (1) YBC (1) , YBG (1) , YBK, YBN (1) | 4.10:1 |
| YAM, YAU, YAW (1) , YBA (1) YBD, YBH (1) , YBL, YBP (1) | 4.56:1 |
| (1) With positive traction, limited slip differential. |
| (1) | With positive traction, limited slip differential. |
"C/K" SERIES REAR AXLE RATIO IDENTIFICATION
| Application & Code | Ratio |
|---|
| 8.5" Ring Gear |
| RKF, RKG (1) | 3.08:1 |
| RKH, RKJ (1) | 3.42:1 |
| RKK, RKL (1) | 3.73:1 |
| 9.5" Ring Gear |
| RKM, RKU | 3.23:1 |
| RKX, RKZ | 3.73:1 |
| RKY (1) , RLA, XZR | 4.10:1 |
| RKR, RKW (1) , LZA | 4.56:1 |
| 10.5" Ring Gear |
| RMU, RMX (1) , SYK, SYP (1) | 3.42:1 |
| RMW, RMY (1) , RMA, RMC (1) , SYL, SYR (1) , XSX, XSZ (1) | 3.73:1 |
| RKY, RLW, RLZ (1) , RMB, RMD (1) SYM, SYS (1) , XSY, XTA (1) | 4.10:1 |
| RMG, RMJ (1) , SYT (1) , XTB, XTC (1) | 4.56:1 |
| (1) With positive traction, limited slip differential. |
| (1) | With positive traction, limited slip differential. |
"G" SERIES REAR AXLE RATIO IDENTIFICATION
| Application & Code | Ratio |
|---|
| 8.5" Ring Gear |
| TYJ, USJ, UUX, UUY (1) , XRA (1) , XRD, XRF (1) , XPR, XPU (1) , XPY | 3.42:1 |
| UUZ, UWA (1) , XPC, XPS, XPW (1) , XPZ, XRB (1) , XRH (1) , XRG | 3.73:1 |
| UMT, UMX (1) | 4.10:1 |
| 9.5" Ring Gear |
| TXN, TXS (1) , RYS, RYX (1) | 3.42:1 |
| TXP, TXT (1) , RYT, RYY (1) | 3.73:1 |
| TXR, TXU (1) , RYU, RYZ (1) , YCK, YCL (1) | 4.10:1 |
| RYW, RZA (1) | 4.56:1 |
| 10.5" Ring Gear |
| RZB, RZF (1) | 3.42:1 |
| RGR, RZC, RZG (1) , SZY, XYS, XZJ | 3.73:1 |
| RZD, RZH (1) , XYT, XYW (1) , XZD, XZF (1) , YAL | 4.10:1 |
| XYU, XYX, XZG, XZH (1) | 4.56:1 |
| (1) With positive traction, limited slip differential. |
| (1) | With positive traction, limited slip differential. |
"K" SERIES REAR AXLE RATIO IDENTIFICATION
| Code | Ratio |
|---|
| ZLS, ZLW | 3.42:1 |
| ZLX, ZLT | 3.73:1 |
| (1) 8.25" ring gear is used on K1 and K2 models. 9.25" ring gear is used on K3 models. No other information is available from manufacturer. |
| (1) | 8.25" ring gear is used on K1 and K2 models. 9.25" ring gear is used on K3 models. No other information is available from manufacturer. |
"K" SERIES FRONT AXLE RATIO IDENTIFICATION (1)
| Application & Code | Ratio |
|---|
| 10.5" Ring Gear |
| SDK, SGB, SDN (2) , SDR, SDU (2) | 3.73:1 |
| SDL, SDS, SDX | 4.10:1 |
| SDM, SDP, SDT, SDW (2) , SDY, SFA (2) , UWS, UWW | 4.56:1 |
| TJY (2) | 4.88:1 |
| SDZ, UWU | 5.13:1 |
| 11.0" Ring Gear |
| UWH | 4.63:1 |
| TFT, TFU, UWJ | 5.13:1 |
| (1) 1994 information not available from manufacturer. (2) With positive traction, limited slip differential. |
| (1) | 1994 information not available from manufacturer. |
| (2) | With positive traction, limited slip differential. |
"P" SERIES REAR AXLE RATIO IDENTIFICATION (1)
| Application & Code | Ratio |
|---|
| 7.625" Ring Gear |
| TFY, YDJ | 2.73:1 |
| TGB, UBR, USZ, UTA, YCM (1) , YDM YDR, YDU, YDK (1) , YDL, YDC | 3.08:1 |
| SZM, SZN (1) , UBT (1) , UTB, UTC (1) , UBS (1) , YDP YDS, YDT, YDW, YDX | 3.42:1 |
| XRJ, XZU (1) , YDY (1) , YDZ (1) | 3.73:1 |
| UYC, XRK | 4.10:1 |
| (1) With positive traction, limited slip differential. |
| (1) | With positive traction, limited slip differential. |
"S" & "T" SERIES REAR AXLE RATIO IDENTIFICATION
| Code | Ratio |
|---|
| ZBX | 3.08:1 |
| SKY, ZBY, ZYD, ZYH | 3.42:1 |
| SKZ, ZPC, ZPU, ZYF | 3.73:1 |
| (1) 7.5" ring gear is used. No other information is available from manufacturer. |
| (1) | 7.5" ring gear is used. No other information is available from manufacturer. |
"T" SERIES FRONT AXLE RATIO IDENTIFICATION (1)
