JD 4020

[70440rt]

I"ve been looking at JD 4020"s and I hope you"ll forgive my ignorance. Can someone tell me the difference between synchronous and a power shift? I was under the impression that the syncro"s were like an automatic, then I was told the pwr shift was a hydro, so now I"m confused. Thanks

 

[twopop]

the synchro is a 8 speed synchromesh trans which means it can be shifted(using the clutch)while moving.it is a hard gear transmission
the powershift is not a hydro trans.it is somewhat like an automatic trans but is shifted w/o the clutch and each gear is contolled individually by the shift lever.in the 4020 it is also a 8 speed trans,the gear change is done by a combination of clutches

 

[Anonymous-0]

The synchro range has four ranges on the left side of the shift quadrant (plus park and tow) that must be shifted while stopped. They are not synchronized. Then in each range there are two forward speeds and one reverse that can be shifted while moving. The groups are 1,3,1r then 2,5,2r, then 4,7, no r, and 6,8 no R.

The power shift has 8 speeds forward and two reverse. One shifter in a J shaped path. All the way back is stop, up the right path is forward, up the left is reverse. There is a pedal where the clutch pedal would be, but its properly called an inching pedal, used just for creeping up to an implement. There is a true clutch, but its on a hand lever for cold weather starting.

Both are tough transmissions, though the Synchro Range is confusing at first.

Gerald J.

 

[tim s]

( 4 reveses)

 

[Anonymous-0]

4 reverses in PS? Only two in SR, while there are four possible the two high speed ones are locked out.

Gerald J.

 

[tim s]

Yes 4 reverse on power shifts two on sychro range and you can grind out the notch on 4th/7th and gain a third reverse, and it is a little fast.

 

[buickanddeere]

While asking 10 different people the same question will get 10 different answers. We maybe able to assist you in tractor choices. If we know you application, situation, mechanical repair ability etc. The 4020 is a classic, but a classic that's getting old and having high hours.