Contents Section: Differentials & Drive Axles All sections

Drive Axle Ratio Identification GMC Cab & Chassis R2500

Identification code or part number for front and rear axle is stamped on forward surface of right axle tube, near carrier.

ApplicationRatio
"K" Series (Automatic Hub)
GPS, ZDC3.08:1
GRB, ZDK, GPZ, ZDH3.42:1
GRP, ZFD, GRG, ZFB3.73:1
GRU, ZFH4.10:1
"K" Series (Manual Hub)
GPT, ZDD, ZDF, ZDG3.08:1
GPW, GPY3.23:1
GRD, ZDL, GRA, GRF, ZDJ, ZFA3.42:1
GRS, GRN, GRT, ZFC, ZFG3.73:1
GRW, GRY, ZFJ, ZFK4.10:1
"S" Series
ZAA3.42:1
ZAB3.73:1
ZAC4.11:1
Astro & Safari 7.5" Ring Gear
FCB, KJM, KRK, HZA (1) , KJR (1) , KRN (1)2.73:1
FFA, KJN, KRL, HZB (1) , KJS (1) , KRP (1)3.08:1
FMA, KJP, KRM, HZC (1) , KJT (1) , KRR (1)3.42:1
FRA, KJU, KRS, HXF (1) , KJW (1) , KRT (1)3.73:1
GWH, KJX, KRU, HZG (1) , KHY (1) , KRW (1)4.10:1
"C" Series 8.5" Ring Gear
BR3, BX3, HXA (1) , HXF (1)2.73:1
CM3, CR3, BS3, BY3, HXB (1) , HXG (1) , HXL (1) , HXN (1)3.08:1
BT3, BZ3, HMR, EXC (1) , HXH (1) , HXP (1)3.42:1
BU3, CA3, BFK, BFN, HXD (1) , HXJ (1) , HXM (1) , HXR (1)3.73:1
"C" Series 9.5" Ring Gear
GTM, GUJ3.23:1
GUB, GUK, KCW (1) , KCZ (1)3.42:1
GUC, GUL, KCX (1) , KDA (1)3.73:1
GUD, GUM, KCY (1) , KDB (1)4.10:1
GUN, KDC (1)4.56:1
"C" Series 10.5" Ring Gear
GUW, GTT, GTX, GWR, GWZ, GUY (1) , GWU (1) , GXU (1)3.73:1
GUX, GTU, GTY, GWS, GXM, GUZ (1) , GWW (1) , GXW (1)4.10:1
GTW, GWT, GXT, GTZ (1) , GWX (1) , GXX (1)4.56:1
"C" Series 10.5 Ring Gear (DANA)
GDP3.73:1
GDR4.10:1
GDS4.56:1
"G" Series 8.5" Ring Gear
BCR, BRD, HYC (1) , HYH (1)2.73:1
BSC, BSD, HYD (1) , HYJ (1)3.08:1
BBN, BBR, HYF (1) , HYK (1)3.42:1
BFU, BFW, HYG (1) , HYL (1)3.73:1
"G" Series 9.5" Ring Gear
HBG, KCT (1)3.23:1
HBB, KCR (1)3.73:1
HBD, KCS (1)4.10:1
HBJ, KCU (1)4.56:1
"G" Series 9.75" Ring Gear (DANA)
BJH, GWG4.10:1
BKH, GWF4.56:1
"G" Series 10.5" Ring Gear (DANA)
BJJ4.10:1
BKJ4.56:1
"K" Series 8.5" Ring Gear
BB3, HYB (1)2.73:1
BC3, BSA, HXT (1) , HXY (1)3.08:1
CX3, BD3, HXU (1) , HXZ (1)3.42:1
CY3, BF3, HXW (1) , HYA (1)3.73:1
"K" Series 9.5" Ring Gear
GXY, GZD3.23:1
GXZ, GZF, KDD (1) , KDH (1)4.42:1
GYM, GZG, KDF (1) , KDJ (1)3.73:1
GYW, GZH, KDG (1) , KDK (1)4.10:1
"K" Series 10.5" Ring Gear
GZM, GZY, GZR (1) , GSY (1)3.73:1
GZN, GZW, GZS (1) , GZZ (1)4.10:1
GZP, GZX, GZT (1) , GDN (1)4.56:1
"K" Series 10.5" Ring Gear (DANA)
GDP3.73:1
GDR4.10:1
GDS4.56:1
"P" Series 9.5" Ring Gear
GCU, GUL, KCX (1) , KDA (1)3.73:1
GUD, GUM4.10:1
"P" Series 10.5" Ring Gear
HSP, HSW, HST (1) , HSZ (1)3.73:1
HSR, HSX, HTB4.10:1
HSS, HSY, HTC, HSU (1) , HTA (1) , HTF (1)4.56:1
HTD5.13:1
"P" Series 10.5" Ring Gear (DANA)
BKN4.56:1
KNT4.88:1
BNB5.13:1
"P" Series 10.5" Ring Gear (ROCKWELL)
HJH5.29:1
HJJ5.83:1
"S" Series (2WD) 7.5" Ring Gear
GAC, GAH, HAH (1) , HZM (1)3.08:1
GAD, GAJ, HZJ (1) , HZN (1)3.42:1
GAF, GAK, HKZ (1) , HZP (1)3.73:1
GAG, GAL, HZL (1) , HZR (1)4.11:1
"S" Series (4WD) 7.5" Ring Gear
HKA, HZS (1)3.42:1
HKB, HZT (1)3.73:1
HKC, HZU (1)4.11:1
(1) With locking type differential.
(1)With locking type differential.

FRONT AXLE RATIO IDENTIFICATION