synchro vs powershift

I do not like the powershift in the 4640 and would much prefer a Quad range. It's a very jerky transmission and you'd find yourself using the clutch anyway.

The powershift allows clutchless gear and direction changes. Deere's Synchro range had four nonsynchronized ranges with a "hi low reverse" synchronized gearset connected to that.

IMHO the powershift has some opernational problems especially for loader work. 1. to go from foward to reverse and vice versa you need to go through all lower gears and back up to the desired gear in the other direction the synchro has the logical working speeds in a straight line. 2. Can't remember which gears but the powershift has a couple of gears where you are trying to shift a bunch of clutchpacks at the same time and it really sucks the power (on a 3020 you will kill the engine unless it is wound up)

JM2CW

JT

You are correct that you don"t have to shift through all the gears. However you do have to move the lever through the positions. The synchro has the logical speeds with direction change in a straight line.

I would tend to agree with you on the quad. All it is, is a synchro with a TA added.

If the use is field work the power shift would be my choice hands down. For loader work I would lean towards the synchro. But that is what I am most familiar with.

JT

power shift: uses single or multiple plantary gears sets and a with wet clutches that work of the shift lever. Shifts like a car with an automatic where you shift 1-3 with the lever and lacks a torque converter. Uses an inching pedal as opposed to a clutch to allow for hooking and unhooking equipment.

synchonized transmissions: like a modern manual transmission in a vehicle. Allows shifting while moving with using the clutch pedal between the synchronized gears, need to be at a stop to shift between the unsynchized gears.

Given the same engine a powershift typcally consumes more power in the transmission for the extra volume of flowing oil and corrsponding waste heat than synchonized or unsynchronized transmissions. My personal bias is in favor of a fully synchronized transmission over either power shift or unsychronized. Once again, only general statements, only direct experience with a 4020 is on the engine.

The power shift uses multiple disc wet clutches and planetary gearsets much like an automotive automatic tranmission. There is no torque convertor, though. Use of the clutch is not needed to shift from a standstill all the way through the gears.