Holden Calais Gearbox & Transmission Problems

The five-speed automatic in your Calais is a bit of an odd one, Mark, as it was only used for a handful of years and only in the high-feature 3.6-litre V6. Holden switched the car to a six-speed automatic in September 2009, so technically, that would be possible to fit to your car. As with a lot of these things, however, it’s not as simple as finding a gearbox and bolting it in. Modern engineering dictates that the five-speed and six-speed transmissions, while physically similar, may have featured bigger differences in terms of the information they fed to the car’s on-board computer and the program within that computer that, in turn, told the gearbox what to do next.

At the very least, you’d need the electronic transmission-control module to make the six-speed work and possibly some changes to sensors and wiring. Even then, you might find that your speedometer needs recalibration. Unlike the good old days when the transmission was simply a set of gears, a modern transmission these days is a much more sophisticated piece of equipment and does a much more complex job.

It could be that you’re driving on the point of torque convertor lock-up, change your speed when it happens.

If the transmission is performing as it should then it could just be a dodgy wiring connection, but having the transmission checked and serviced is a wise course of action.

IT LOOKS like you've been given a factory fix, and it has worked. We have had sufficient complaints about the six-speed auto box to make us think something fishy is happening. Anyone with a similar problem should contact their dealer. If that doesn't get the required response, contact Holden direct.