Transmission Gear Ratio

[Oonrahnjay]

      On the Allison transmission website, they list the gear ratios of a transmission.  There will be a table with the listings of the gears (incl. reverse) but there is a statement "Not Including the Gear Ratios of the Torque Converter".  Is there a usual ratio of the torque converter to be multiplied to the internal gearing to get the overall ratio for each gear?

Thanks,  BH NC USA

[lostagain]

The ratio of the torque converter is variable, because the fluid is what makes the connection from one side to the other of the converter, and it slips, a lot when you first start out from a stop, then progressively less as you gain speed.

Once the trans locks into a gear such as first and second, then the ratio is fixed and is a known figure that can be published.

That is the way I understand it anyway.

JC

[luvrbus]

Depends on stages the torque converter has then they have a stall ratio also, most newer torque converters are 3 stages but still a lot of the older single stage converters around don't you read here about the rough shifting on a 740 lol

good luck