The clutch is a conventional clutch and so is the 3 speed gearbox. The good thing about this is that there is no loss of power through to the gearbox. The hydraulic multi-power clutch is not torque converter, but is merely a multi-plate hydraulically operated clutch pack. This is also why if you are in high multi going up a hill and you depress the clutch pedal that whilst in gear no roll-back can occur because of the ratchet clutch.
It is for this reason that there is engine braking in high multi power, but no engine braking in low multi power. To better understand each position in the 17-digital serial number, the chart below lists the position number, use of that position and what the position means, specific to large tractors (7030 Series Large-Frame, 8R/8RT Series and 9030 Series Tractors). Because the drive is now turning faster than through the low-multi ratchet clutch, this now becomes a free-wheeling device. When you move the transmission to high multi it locks up the hydraulic clutch and the hydraulic clutch gear drives another gear. There is no engine breaking in low multi because of the ratchet clutch. When in low multi the hydraulic clutch is dissengaged and the drive goes through a pair of gears into a ratchet clutch which takes the drive to the gearbox. With the multi-power system there is one hydraulic clutch pack and also a ratchet type assembly. What really seems to intrigue people is that the engine braking system works when in high multi-power, but there is no engine braking when in low multi-power………
We are often asked how the multi power system on models such as the Massey Ferguson 65, 135, 165 etc. Want to check out our tractor maintenance videos? Click here to see what we've got!