Originally submitted by T:
- 1 Types of Trimatics:
- 1.1 Bellhousings:
- 1.2 V8 Trimatics:
- 1.3 6 Cylinder Trimatics:
- 1.4 Early Type:
- 1.5 Early Type With Cable Kickdown:
- 1.6 Early Type With Solenoid Kickdown:
- 1.7 Later Type:
- 1.8 Later Type Trimatics With Solenoid Kickdown:
- 1.9 Dipstick Tube:
- 1.10 V8 Trimatics:
- 1.11 EFI VK Trimatics:
- 1.12 EST Trimatic:
- 1.13 Column Shift:
- 1.14 T Bar:
- 1.15 Selector Lever:
- 1.16 Gearset:
- 1.17 Links:
- 1.18 Terms:
Types of Trimatics:
Trimatics have been fitted to a range of cars from 4 cylinder to 8 cylinder. Different Bellhousings, Torque-Converters, Clutch Packs and Shift Valves have been fitted to accommodate the differing requirements of each engine.
383HGBrougham on Sat, 02/05/2009 - 10:01. Only the 6 cylinder transmission has both the half and full circle bellhousing!
V8 transmissions use the same half circle bellhousing. 383HGBrougham on Sat, 02/05/2009 - 14:06. you need to be aware there was also a V8 Chev bellhousing for a trimatic transmission that was fitted for the vehicles exported to South Africa and a different bellhousing for Gemini as well. End of submissions by 383HGBroughm.
The V8 Trimatic uses a larger Bellhousing and Torque Converter than a 6 Cylinder Trimatic.
6 Cylinder Trimatics:
The 6 Cylinder Trimatic uses a smaller Bellhousing and Torque Converter than a V8 Trimatic .
HG - HZ Six Cylinder. The early type Trimatic uses a half height Bellhousing which uses a removable tinplate cover. This cover follows the curve of the Torque-Converter. This gearbox was the first type of Trimatic and existed up to the end of HZ. Note that the oil filler neck is unique to this gearbox. The bellhousing/engine bolts are short and each boss that the bellhousing/engine bolts tighten up to are also short. If the bolts from a later model gearbox are used they will bottom in the engine holes and not secure the bellhousing properly. The correct length bolt must be used for the early type gearbox. The early type oil filler neck expects a thin boss in order to enter the filler neck hole vertically. HG was exclusively Cable Kickdown, HQ used either Cable or Electric, HJ and later were exclusively Electric Kickdown.
Early Type With Cable Kickdown:
HG - early HQ Six Cylinder. The earliest Trimatics had the contoured lower service cover and used a Mechanical Cable to activate the Kickdown. Trimatics were Cable Kickdown until mid HQ.
Cable Kickdown Adjustment:
The difference between the amount of protruding Kickdown Cable at Full Throttle and Idle should 8.13mm. Adjust the Outer Cable adjusting Nuts until this measurement has been obtained.
Early Type With Solenoid Kickdown:
Late HQ Six Cylinder onwards. Early Trimatics had a contoured lower service cover and used an Electrical Solenoid to activate the Kickdown. Trimatics were Electric Kickdown from mid HQ on.
UC, VB and WB onwards Six Cylinder. The later type Trimatic has a vertically mounted service cover plate because the Bellhousing is fully enclosed. This gearbox appeared around the time of the VB Commodore. A Trimatic with a 360 degree Bellhousing is sometimes referred to as the Spaceage Bellhousing or Moonshot Bellhousing.
Later Type Trimatics With Solenoid Kickdown:
UC, VB and WB Six Cylinder onwards. All the later type Trimatics used Electric Solenoid Kickdown.
On Six Cylinder Trimatics, it's important to keep the Dipstick Tube with the Trimatic. Dipstick tubes changed with different models of Trimatic and not using the correct Dipstick tube will cause Oil Leaks where the Dipstick Tube enters the Trimatic.
The V8 Trimatic in both the Early and Later type uses a different Flex Plate and a different Torque-Converter. Not only does the Torque-Converter have a different Stall Characteristic it is physically different in appearance as well.
Within the gearbox itself there are more clutch plates in each Clutch Pack and the shift valves are different to accommodate different shift rates and times.
EFI VK Trimatics:
The EFI VK Trimatic Bellhousing has extra ribbing as well as being the later full type with thick mounting Bosses. This 6 Cylinder has increased power over the EST black six.
The EST Trimatic Bellhousing is half height and has an Hole in the top for mounting the EST Speed Sensor as in the Photos.
Column shift Trimatics have the Selector Lever on the driver's side of the gearbox.
Pre-Commodore Holdens have a T-Bar mechanism that connects to the offside of the Trimatic. Commodore Holdens have a T-Bar mechanism that connects to the nearside of the Trimatic.
If you intend to replace a Trimatic, the location of the Selector Lever (left side or right side) is critical.
Not all Tri-matic gearsets are the same. The early boxes (HG/LC) with the cable detent have a weaker gearset with different ratios. These early (weaker) gearsets were still used in the Euro boxes (Fiat/Rover/Volvo etc.). From memory I think the early ratios are 2.40 & 1.48 for 1st & 2nd gear, while the electric detent boxes (HQ onwards) have 2.31 & 1.46 1st & 2nd gear. The Aussie gearset (2.31/1.46) are very tough & don't usually fail, I believe that they're tougher than TH350 gears. Dr Terry