Holden Monaro, HQ

Automatic transmission fluid capacity & service interval

Holden Monaro, HQ automatic transmission fluid capacity ranges from 1,7 to 10,4 liters. Service intervals are 5000 km or 3 months. The data covers 8 configurations.

The configuration chart below lists fill volumes and service intervals for each engine and trim variant.

TypeSpecifications
Monaro V8 GTS, HQ 253 LC (1971-1974)
  • Use: Normal
  • Capacity 8,7 liter (Dry fill)
  • Capacity 1,7 liter (Service fill)
  • Check 5000 km/ 3 months
  • Code: Trimatic 3/1
Monaro V8 GTS, HQ 253 LC (1971-1974)
  • Use: Normal
  • Capacity 10,4 liter (Dry fill)
  • Capacity 3,7 liter (Service fill)
  • Check 5000 km/ 3 months
  • Code: Turbo-Hydramatic 3/1
Monaro V8 GTS, HQ 253 HC (1971-1974)
  • Use: Normal
  • Capacity 8,7 liter (Dry fill)
  • Capacity 1,7 liter (Service fill)
  • Check 5000 km/ 3 months
  • Code: Trimatic 3/1
Monaro V8 GTS, HQ 253 HC (1971-1974)
  • Use: Normal
  • Capacity 10,4 liter (Dry fill)
  • Capacity 3,7 liter (Service fill)
  • Check 5000 km/ 3 months
  • Code: Turbo-Hydramatic 3/1
Monaro V8 GTS, HQ 308 HC (1971-1974)
  • Use: Normal
  • Capacity 8,7 liter (Dry fill)
  • Capacity 1,7 liter (Service fill)
  • Check 5000 km/ 3 months
  • Code: Trimatic 3/1
Monaro V8 GTS, HQ 308 HC (1971-1974)
  • Use: Normal
  • Capacity 10,4 liter (Dry fill)
  • Capacity 3,7 liter (Service fill)
  • Check 5000 km/ 3 months
  • Code: Turbo-Hydramatic 3/1
Monaro V8 GTS 350, HQ 350 HC (1971-1974)
  • Use: Normal
  • Capacity 8,7 liter (Dry fill)
  • Capacity 1,7 liter (Service fill)
  • Check 5000 km/ 3 months
  • Code: Trimatic 3/1
Monaro V8 GTS 350, HQ 350 HC (1971-1974)
  • Use: Normal
  • Capacity 10,4 liter (Dry fill)
  • Capacity 3,7 liter (Service fill)
  • Check 5000 km/ 3 months
  • Code: Turbo-Hydramatic 3/1

Additional Notes

  • Across all listed configurations of the Holden Monaro and HQ series from 1971-1974, two distinct automatic transmission dry fill capacities appear: 8.7 litres and 10.4 litres. A dry fill figure represents the total fluid volume required when filling a completely empty transmission, such as after a full overhaul or unit replacement.
  • The service fill capacity is listed at either 1.7 litres or 3.7 litres depending on the configuration. A service fill reflects only the volume needed to top up or refill after a routine fluid drain, which recovers far less fluid than a complete teardown, explaining why service fill values are substantially lower than dry fill values.
  • The gap between the 8.7-litre dry fill and the 1.7-litre service fill for the same configuration indicates that a standard drain procedure leaves a significant portion of fluid retained within the torque converter and transmission passages. The 7.0-litre difference between those two figures reflects fluid that remains in the system during a typical service.
  • For configurations listed with the 10.4-litre dry fill, the corresponding service fill rises to 3.7 litres. The larger retained volume in the lower-capacity variant and the comparatively higher service fill in the 10.4-litre variant suggest a different transmission unit or torque converter pairing is involved across the two capacity sets.
  • The 253 HC, 253 LC, 308 HC, and 350 HC engine variants all share the same two capacity pairings — 8.7/1.7 litres and 10.4/3.7 litres — under normal use conditions. No engine displacement among the listed variants produces a unique capacity specification exclusive to that engine.
  • The fluid check interval is uniformly specified at 5,000 km or 3 months across every listed configuration under normal use conditions. The dual-trigger format means whichever threshold is reached first would prompt a check, regardless of whether driving distance or elapsed time is the limiting factor.

Other Systems