Tractor transmission question?

[stumpfield]

Can someone help explain what this mean?

TRANSMISSION
Number of Speeds
12 forward, 12 reverse
Forward-Reverse Synchro-Shuttle with partial synchromesh

I know it's a 12-speed gear transmission with a shuttle so you get the same number of forward and reverse gears. How is this different than any other gear transmission? Is this type of transmission suitable for loader work by someone used to HST? What's the sequence of operation when you want to scoop and bucket of gravel and dump into the bed of pickup truck on not so level ground and not hitting the truck? How similar or different than driving a car with standard transmission? Any help is appreciated.

 

[Whitey]

I think that you are right 12 forward and 12 reverse. I also believe that you can shift on the fly. With my gear drive JD 770 (Synchro shift) you have to come to a complete stop to shift. However that also can be a safety factor for it makes you think and operate a little slower. Clutching a load into a dump on any grade is not recommended no mater what kind of transmission you have. If I have a difficult load I use low gear. I prefer a gear drive because I can set the throttle and go. OK here comes the big debate! I am currently looking for another tractor and would consider the shuttle shift before a hydro.

JD 770 / 70 FEL / 7 BH - 425 AWS / 54" MMM / 54" FMP

 

[piller]

OK, I'll take a stab at it.
It's got 12 Forward and 12 Reverse speeds.
It's got a shuttle shift, the shuttle goes Forward <-> Reverse (with neutral in the middle perhaps).
The shuttle shift is synchronized, you can shuttle shift while moving, this is good for loader work.
I think this is a manual shuttle shift which requires you to clutch for the shuttle shift operation.
The partial synchromesh means that when you are moving forward (or reverse) you cannot shift on the go from 1st to 2nd to 3rd etc. However, the transmission will probably have two synchronized gears that you can shift between while on the go, for example you can shift from 2nd to 5th. Any other shifts would not be synchronized and would require that you stop the tractor. Hope this helps.

 

[JerryG]

Can someone help explain what this mean?

TRANSMISSION
Number of Speeds
12 forward, 12 reverse
Forward-Reverse Synchro-Shuttle with partial synchromesh

The shuttle part will be synchronized and the 3rd and 4th gears will also be synchronized.

You can shift back and forth between the third and fourth gears in each range without stopping by using the clutch. (edit: you can also shift from 2-3rd but not from 3rd back to 2nd.)

The forward and back shift is synchronized so it won't grind when you shift with the clutch.

 

[stumpfield]

Thanks for helping me understand this. Actually, it's a 4 speed transmission with L-M-H ranges. I'm curious as to why only the 3rd and 4th gears are synchronized. Is this typical on most gear tractors?

 

[Charlie175]

4th could possibly be to "high" to take off from a stop thus they syncro it from 3rd.