HK/HT/HG Gearbox Ratios
Page created by Qute Mar 13th 2005:
==HK/HT/HG Gearbox Ratios:==
|Type ||Reverse|| First ||Second ||Third||Fourth|
|Powerglide (6 Cyl)||Automatic||1.82:1||1.82:1||1:1|
|Trimatic (6 Cyl) HG||Automatic||1.85:1||2.31:1||1.46:1||1:1|
|3 Speed (Sync)||Manual||3.59:1||3.07:1||1.68:1||1:1|
|4 Speed Opel (6 Cyl Only)||Manual||3.317:1||3.428:1||2.156:1||1:1|
|4 Speed (M21)||Manual||2.54:1||2.54:1||1.80:1||1.44:1||1:1|
|4 Speed (M22)||Manual||2.85:1||2.85:1||2.05:1||1.35:1||1:1|
===The M22 Gearbox:===
Submission by Dr Terry.
The M22 gearbox in the HK/T/G series is a Saginaw box & is nothing like the M22 box used in the HQ-WB 6 cyl commercials. The HQ-WB M22 box is an Aussie 4-speed similar to the normal M20/M21 boxes in the HQ-WB series.
The M22 Saginaw box has the 1st gear ratio of 2.85, but the M22 Aussie has a 1st gear ratio of 3.74. The combination of the 4.44 diff & the 3.74 1st gear was fitted so that a 6 cyl 1 Tonner could still do a hill start on a steep hill without burning out the clutch even if it was overloaded.
The best diff to fit in its place for street use, would be the 3.08 & keep the M22 box. It still has a nice low 1st gear so your clutch will last but top gear is 1:1 same as any other 4-speed.
Introduced with the 1967 HR 186S, Opel 4 Speed All synchro Gearbox. Avaliable in 6cyl only, standard on Monaro and Monaro GTS with the 186S. A Weak box, originally designed for German Opel 4 cylinder cars. Even a standard 161 could break one within 50K miles.