How to distinguish between Fast and large 8-speed gearboxes?

It mainly depends on the size of the center distance.

The center distance of the gearbox is the distance between the two middle points of a group of gear pairs that are relatively meshed. The larger the center distance, the greater the torque bearing capacity of the gearbox. The larger the center distance, the larger the gears in the transmission and the more torque it can handle.

At the beginning of the design of the Fast eight-speed box, there are three different center-to-center distance sizes, namely 105mm, 116mm, and 148mm.

1. Small eighth gear, input torque 550Nm-850Nm
Among them, the gearbox with a center distance of 105mm has an input torque range of 550 Nm to 850 Nm. For example, our common model is 8JS55E/65E/85E gearbox, the input torque is 550 Nm -850 Nm, in order to distinguish, it is called “Fast small eighth gear” internally or externally.

2. Small eighth gear input torque 1050Nm-1250Nm
With a gearbox with a center distance of 116mm, the input torque range is between 1050 Nm and 1250 Nm. For example, our common gearbox is 8JS118/110, and the input torque of the gearbox is in the range of 1050 Nm to 1250 Nm. It is called the “Fast small eight-speed” gearbox.

3. The eighth gear, the input torque is 1200 Nm – 1800 Nm
The last center distance is 148mm, and the input torque range is 1200Nm-1800Nm. This kind of gearbox is not very common, and the models are 8JS130TA-B, 8JS180TA-B and 8JSX180T. It is called “Fast Extra Large 8th Gear or Normal 8th Gear”.

 How about it, is it very simple, if you still can’t tell the difference, just compare the torque above.