Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
General Motors
Identification code for rear axles is stamped on rear surface of right rear axle tube. Identification code for front axles is stamped on top rear of left axle tube. On Dana built front axles, axle ratio code is on tape stripe around right front axle tube.
| Code | Ratio |
|---|---|
| Conventional Rear Differentials | |
| KYA, KYB, KYJ, KYK, KYN | 2.56:1 |
| TUF, TUM, TAB, TUH, TAS, TAA, TAR, TUR, KCX, TAF, TAM, TAN, KCA, KBS | 2.73:1 |
| TWA, KXT, TWB, TAU, KXS, TBJ, KCF, KXX, TBF, TWF, TBH, KXN | 3.08:1 |
| TKB, TKU, RMM, RMB, RMR | 3.21:1 |
| TCA, TXB, TKK, TKM, TXC, TCF, TCJ, TKN, TKR | 3.23:1 |
| KZA, KZB, TDR, TXF, TDS, KHN, KHU, KHB, KHR, KZJ, TDU, TDN, TDW, TDY, KZF, KZK, KHJ, KHK, KDN, KHD | 3.42:1 |
| CSA, CSB, CSC, CSD, CSF, CSH, KBU, KBA, KBH, KBX, TFA, TXA, TFJ, TFB, TFH, KBU, TJN, TJS, TFK, RJZ, RJA, TJK, KKC, KKA, KKJ, TKW, TKC, KBD, KKX, KKW, KBN | 3.73:1 |
| RRM | 3.75:1 |
| KND | 4.09:1 |
| RHN, TXD, KMN, RHA, KJB, KMH, KMC, KMT, THF, RHC, RHD, KUN, RHN, THC, THD, KUB | 4.10:1 |
| KRA | 4.11:1 |
| TRB, TJB, TJC, KFA, KSN, KSF, KRJ, TJF, KRU, KSY, KRC, KSZ | 4.56:1 |
| KTA | 5.13:1 |
| Locking Rear Differentials | |
| KYC, KYD, KYF, KYH, KYR | 2.56:1 |
| TUJ, TUK, TUN, TAT, KCY, TAW, KCB, TWC, TAD, TAC, TAH, TAK, TUZ | 2.73:1 |
| KXW, TWD, KCH, KXU, TBM, KXY, TBU, TBD, KXR | 3.08:1 |
| RMN | 3.21:1 |
| KZC, KHA, KHT, KHW, TCC, TDT, KZU, KHC, KHS, KZD, TDX, KZF, KHM, KDR | 3.42:1 |
| CNA, CNB, KBY, CSJ, CSK, TKX, TFF, TJR, TJM, TJT, TJA, KKU, RJB, KKF, KKY, KKD, TKD, KBF, KBJ, KBR | 3.73:1 |
| RRN | 3.75:1 |
| KNF | 4.09:1 |
| KUD, KUF, KUR, KJC, KMD, KMU, THB, RHB, RHM, RHR | 4.10:1 |
| KRB | 4.11:1 |
| KFB, KRD, KRK, KRW, KSH, KSR, KST, KSU, KWA, KWB, TJD, TRC, | 4.56:1 |
| Front Differentials | |
| WK | 2.56:1 |
| WA | 2.73:1 |
| THC, WB | 3.08:1 |
| TFA, WC | 3.23:1 |
| THA, THD, WF, WH | 3.42:1 |
| TBA, TBB, TBF, TBJ, WM | 3.73:1 |
| TCA, TCB, TCC | 4.10:1 |
| TDA, TDB | 4.56:1 |
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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