MODEL IDENTIFICATION
| Series (1) | Model |
|---|
| "C" | 2WD Pickup, Sierra & Suburban |
| "G" | RWD Van |
| "K" | 4WD Blazer, Pickup, Sierra, Suburban & Yukon |
| "L" | All-Wheel Drive Astro & Safari |
| "M" | 2WD Astro & Safari |
| "P" | Commercial Van/Motorhome |
| "S" | 2WD Blazer, Jimmy, Pickup & Sonoma |
| "T" | Bravada, 4WD Blazer, Jimmy |
| *** | Pickup, Sonoma, Syclone & Typhoon |
| (1) Vehicle series is fifth character of VIN. |
| (1) | Vehicle series is fifth character of VIN. |
CORPORATE 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.
ROCKWELL BUILT AXLES
Identification code is stamped on carrier assembly.
| Application & Code | Ratio |
|---|
| 7.625" Ring Gear |
| USM, USN (1) | 3.23:1 |
| USR (1) , USU, USW | 3.42:1 |
| USY (1) , USX, UST (1) , USS | 3.73:1 |
| (1) With positive traction, limited slip differential. |
| (1) | With positive traction, limited slip differential. |
ASTRO & SAFARI REAR AXLE RATIO IDENTIFICATION
Note. Front axle on Astro/Safari is balanced with pinion flange modified to act 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 available from manufacturer.
| CAUTION | Prior to replacement of axle assembly, it is essential that position of drive shaft relative to all driveline components be observed and marked for reassembly reference. Attach drive shaft to replacement axle first, then to transfer case, and road test. If vibration is noted, reindex drive shaft to transfer case and test drive again. |
AXLE RATIO & IDENTIFICATION
| Application & Code | Ratio |
|---|
| 7.625" Ring Gear |
| SKY, ZYD, ZYH | 3.42:1 |
| SKZ, ZYF | 3.73:1 |
ASTRO & SAFARI FRONT AXLE RATIO IDENTIFICATION
| Application & Code | Ratio |
|---|
| 8.5" Ring Gear |
| XPN (1) , XRT (1) | 3.08:1 |
| UUS, XPF, XPJ (1) , XPM, XPP (1) | 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) , XRC | 4.10:1 |
| RYD, RYJ (1) | 4.56:1 |
| 10.5" Ring Gear |
| RYK, RYN (1) | 3.42:1 |
| RYL, RYP (1) , SJM, SZX (1) | 3.73:1 |
| RYM, RYR (1) , SJN, SJR (1) , SJT, SJW (1) | 4.10:1 |
| RDP, SJP, SJS (1) , SJU, SJX (1) | 4.56:1 |
| 11" Ring Gear (UXG) | 4.63:1 |
| (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 |
| XUA, XUB (1) , RZJ, RZM (1) , SFB | 3.73:1 |
| SFF (1) , SFJ, SFM, SJM, SZZ | 3.73:1 |
| RZK, RZN (1) , SFC, SFG (1) , SFK, SFN (1) , SFX | 4.10:1 |
| SFY (1) , SJW (1) , SZW (1) , SZS, XUC, XUD (1) | 4.10:1 |
| RLK (1) , RLZ, RZL, RZP (1) , SFD, SFH (1) | 4.56:1 |
| SFL, SFP (1) , SFZ, SGA (1) , XAF | 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 | 4.10:1 |
| RKR, RKW (1) | 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 |
| RLW, RLZ (1) , RMB, RMD (1) , SYM, SYS (1) , XSY, XTA (1) | 4.10:1 |
| RMG, RMJ (1) , SYN, 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 |
| 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 |
| XPX (1) , XPT | 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) | 4.10:1 |
| RYW, RZA (1) | 4.56:1 |
| 10.5" Ring Gear |
| RZB, RZF (1) | 3.42:1 |
| RDM, RZC, RZG (1) , SZY | 3.73:1 |
| RZD, RZH (1) , RDN, RDR (1) , RLG, RLH (1) , XPT, XPX (1) | 4.10:1 |
| RDP, RDS (1) , RLJ | 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 |
|---|
| ZHW, ZLS | 3.42:1 |
| ZBL, ZGT | 3.73:1 |
| (1) No other information is available from manufacturer. |
| (1) | No other information is available from manufacturer. |
"K" SERIES FRONT AXLE RATIO IDENTIFICATION (1)
| Application & Code | Ratio |
|---|
| 10.5" Ring Gear |
| SDK, SGB, SDN (1) , SDR, SDU (1) | 3.73:1 |
| SDL, SDS, SDX | 4.10:1 |
| SDM, SDP, SDT, SDW (1) , SDY, SFA (1) , TJT, TJX | 4.56:1 |
| TJY (1) | 4.88:1 |
| SDZ, UWU | 5.13:1 |
| 11.0" Ring Gear |
| UWH | 4.63:1 |
| TFT, TFU, UWJ | 5.13:1 |
| (1) With positive traction, limited slip differential. |
| (1) | With positive traction, limited slip differential. |
"P" SERIES REAR AXLE RATIO IDENTIFICATION
| Application & Code | Ratio |
|---|
| 7.5" Ring Gear |
| UBA, UBB (1) , XUF, XUG | 3.73:1 |
| UBC, UBD (1) , XUH, XUJ (1) | 4.11:1 |
| 7.625" Ring Gear |
| TFY | 2.73:1 |
| TFZ (1) , TGA, TGB, UBJ, UBR, USZ, UTA, UWG | 3.08:1 |
| SZM, SZN (1) , TBS, TGF, TGH (1) , UBK, UBL (1) | 3.42:1 |
| UBT (1) , UTB, UTC (1) , UUL (1) , XAZ (1) | 3.42:1 |
| (1) With positive traction, limited slip differential. |
| (1) | With positive traction, limited slip differential. |
"S" & "T" SERIES REAR AXLE RATIO IDENTIFICATION
| Code | Ratio |
|---|
| ZAH | 3.08:1 |
| SKY, ZXC, ZYD, ZYH | 3.42:1 |
| SKZ, ZYF | 3.73:1 |
| (1) No other information is available from manufacturer. |
| (1) | No other information is available from manufacturer. |
"T" SERIES FRONT AXLE RATIO IDENTIFICATION (1)
