Trimatic Install Tips
Originally submitted by T:
- 1 Trimatic Installation Tips:
Trimatic Installation Tips:
Removing the Trimatic Gearbox:
When seperating a Trimatic Gearbox from a car, the Torque-Converter must be unbolted from the Starter-Plate, pushed well back into the Bellhousing and pinned back there by wiring it into place or by bolting it back into place using a Special Tool. Note that in the rearmost position the Torque-Converter will contact a part of the Bellhousing and therefore will not rotate properly. It is imperative the Torque-Converter is positioned in the rear most position. If it moves forward prematurely it will become uncoupled from the Stator, Centreshaft, Turbine and Oil Pump and cause serious alignment problems when the Trimatic is refitted to an Engine.
Removing the Torque Converter:
After the Trimatic has been removed from the Engine the Torque Converter can easily be removed by sliding it forward from the Bellhousing. Take care to keep your Fingers out from under it. The Torque Converter is an heavy item.
Reseating the Torque-Converter:
If the Torque-Converter has been moved forward while the engine is removed it will have become unengaged.
Engagement of the Torque-Converter is vital since it ensures that the elements inside
it (notably the Turbine and Stator) and the Oil-Pump (outside it) make proper connection.
To Fit the Torque Converter:
1. Position the Oil Pump Tabs so that one is a the very top and the other at the very bottom as in the bottom Photo. 2. Position the large Indents in the Torque Converter Spout so they are also in the top and bottom position. 3. Fit the Torque Converter to the Input Shaft gently wobbling it from side to side to make each of the first 2 Splines engage. 4. Next comes to the Oil Pump Tabs. Very slightly turn the Torque-Converter first to the left, then to the right to make the Tabs and Indents line up while you wobble the Converter from side to side. 5. Once engaged, push the Torque Converter all the way back into the Bellhousing. When fully installed there will only be about 1/4" clearance between the Bellhousing and the back of the Torque Converter. In many cases it will not be possible to rotate the Torque Converter in the rearmost position because it will collide with the Casing. Adequate clearance exists only when the Converter is moved forward after being bolted to the Starter Plate . 6. Secure the Torque Converter all the way back in the Bellhousing with a length Wire that can be easily removed after fitting the Trimatic. You don't want the Converter to move forward until after the Trimatic is fully bolted to the Engine.
The Crankshaft Locator:
A Sleeve (Locator) is inserted into the gearbox end of the crankshaft. The dowel ensures that the engine end of the Torque-Convertor is held securely in the centre of the crankshaft. Ensure that a Crankshaft Locator is installed and is in good condition before reconnecting the Trimatic to the engine. When removing the Torque-Converter the Locator will either stick inside the crankshaft, adhere itself to the Torque-Converter or fall out on the ground.
Adjusting the Gear Selector:
After replacing a Trimatic the Gear Lever may need adjusting to ensure that the indicated
position of the Gear Lever (the lever inside the cockpit) matches the actual gear that is selected by the Selector Lever (the lever that is attached to the outside of the gearbox).
To do this, loosen the pinch bolt that holds the Selector Lever's shaft to the Gear Lever. Push the Selector Lever all the way forward. This will place the gearbox in Park.
Now locate the Gear Lever into the Park position and tighten the pinch bolt.
Check the operation of the Gear Lever and ensure that the engine will crank in Neutral and Park.
EST 3.3 VK Commodores have a Dowell in the end of the Crankshaft. Even though the Starter Plate will only fit in one position, the Dowell is there to make for a precise fit . The precision fit of the Starter Plate is necessary for the Electronic Spark Timing to work properly.
Ian. I have been trying to get to the bottom of this and I have been told that a 3mm gap is fine and normal. I have been told that there are some after market flex plates out there which are not quite 100% true to std and they may cause alignment problems.
I was also told today that a common problem is that people fit the flex plate and then fit the bush, which can make the bush sit further out than it should.
Something else to look out for is that a manual spigot has been knocked in to the crank and then the auto bush fitted after that, which does not allow the auto spigot to fit as far in to the crank as it should.
I have also had confirmation that there are only three types of converter for the 6 cyls.
A early type which uses imperial nuts and bolts to secure it to the flex plate.
A later type which use metric bolts with fixed mounting points on the converter.
The third type which is the same as later type but also has pick up pins/lugs for the EST timing set up.
Excessive Flexplate Gap:
Well spoke to the "guru" at the auto specialists today and we seem to finally have nailed down the problem - its the ground down locator. It seems the locator does more than just locate the torque converter when you are assembling it, it is designed so that it puts a tension between the torque converter and the flex plate. This is my understanding of how it works from talking to the trans guy: The centre of the flex plate is held by the six bolts bolting it to the crank, and the locator positions the converter both radially and to the correct distance from the crank, it forms a solid mount from the crank to the centre of the torque converter. When assembling there should be a small gap between the torque converter pads and the flex plate pads, which is taken up by the torque converter bolts placing the flex plate under a slight tension. In this way it is held by the three torque converter bolts as well as being supported in the centre. With the ground down converter, the centre support is gone allowing more flex on the plate, with the additional load of towing the van, its allowing enough flex to walk out the pump bush which in turn chews out the pump seal. So now I am "just" up for a overhaul of the box, a shift kit, heavy duty torque converter, forged servo piston, new locator and new flex plate ...... Hmmm big dollars but it should be all good from here BTW that youtube clip isn't my car its something I came accross researching. Thanks again for the interest and feed back, I feel pretty confident in saying the bodgy mod done to the locator has been the problem that has cost me a lot of dollars and frustration... As to why the mod was done, my guess is that when the trimatic was being put on originally (14 years ago) the gap that should be there to be taken up by the converter bolts was misinterpreted as being a problem, and the locator was ground down to "fix" it. It was fine under the relatively light loads of just the car and even under hard acceleration with just the car wasn't a problem (short bursts). When I started towing, the load on the torque converter went from about 1200 kgs to closer to 2200 kgs maybe even more when you take into account the gear in the back of the ute; a significant increase in load and continuous as well. This caused the flex plate to flex enough to bring on the problem. The last picture in the first post shows the modified locator versus a standard one. Cheers