Jinma 284 transmission - ease of use

[Foggy]

Hi all,

My second post about Jinma transmissions - apologies for obsessing....

A big chunk of my tractor time will be spent mowing my 5.5 acre property, and the rest will be doing FEL and other project work. At this stage I'm leaning towards a Jinma 284 with shuttle shift, 4-in-1 loader, and 5' finish mower.

I've read more posts than I care to think about regarding the merits or otherwise of geared vs HST transmissions, but since the Jinma 284 isn't offered with HST this is somewhat academic.

The thing I'm tying myself in knots over is NOT whether one transmission type is better than another, but IF I have a tractor with a non-synchro geared tranny (ie, a Jinma 284), what are the operational characteristics?

For example, I've set the engine RPM to deliver the required 540 rpm to my finish mower, I've selected a gear appropriate to complete a long straight run /up-down a gentle slope, and now I'm approaching the turn for the next run. At this point I'm figuring I need to slow down if I don't want to end up in the neighbour's chicken coop - how do I smoothly and efficiently complete the turn? Brakes, throttle change, gear change, panic, pray,....?

I know this is a pretty basic question, but it'd sure help me clear my thinking if you could help me out with a little of your hard won experience /forums/images/graemlins/smile.gif

Cheers, Foggy

 

[billbill1]

You could use the foot throttle and just ease off or push the hand throttle up, both will slow you down.

 

[Foggy]

Thanks Bill

But won't easying up on the throttle drop rpm to the PTO (and, say, my mower deck)? Is it possible to turn (say 90 degrees) while maintaining the PTO speed?

I know all those fancy shmancy HST tractors deliver a constant PTO speed regardless of what you're doing (within reason), so I'm wondering whether you can achieve the same effect with a manual non-synchro tranny.

You'll appreciate this is all theoretical for me at the moment since I still don't actually own a tractor (my 17.5hp JD ride-on doesn't count as a tractor) /forums/images/graemlins/smile.gif

Cheers, Foggy

 

[RonMar]

You depress the clutch half way. This disengages the transmission but leaves the PTO engaged(2 stage clutch) and at full RPM. You then coast to a stop, or apply brakes then select a slower gear for the corner. With the relatively small brakes on a tractor, I would not reccomend this if you are going down much of a hill as you might speed up instead of slow down when you depress the clutch. If working down hill, I would select a gear and speed that allows you to make the pass and the turn at the end without disengageing the transmission.

I have never really encountered this problem on a larger tractor. These things are top heavy, have no suspension and relitively high tire loading(small footprint and high weight per sq/ft for traction). The tires provide little shock absorbtion. Turf tires would help a bit with this but the 284 is still pretty heavy. This makes for a pretty rough and uncomfortable ride over all but the smoothest terrain when trying to go at any speed. You are probably going to want to go slower for that reason alone. The mower hanging off the back is going to get bounced pretty good if you are going to be going at any speed. This is hard on the hitch and the mower. In my experience, I select a tractor speed that dosn't tear things up(me included), and that allows me to maneuver around obstacles and cover the terrain. "Set it and forget it", then I can concentrate on cutting without missing spots or be prepared to stomp on the clutch and brake if the machinery starts making loud expensive noises. At this speed, it will take as long as it will take, but you and the machine will be fit to do it again the next time.

 

[JohnS]

Depending on how fast your ground speed is, you might not need to downshift to make the turn.

If your ground speed is too fast to negotiate the turn, you will need to:

- Push in the clutch (half way to stop tractor movement, but let pto keep turning)

- Depress brake to bring the tractor to a complete stop

- Put transmission in lower gear that will have the lower ground speed you feel comfortable to make the turn.

- Release clutch and brake, and negotiate the turn.

- Repeat process to put back in a higher gear, to travel the straight paths


When I field mow, can't always do a turn, so it requires a shift into reverse, but same process. For you, with a shuttle shift, a reverse should be easier. For me, many times this requires two shift lever change. Hi-Lo range change and gear change. Your reverse should be matched to whatever forward speed you have selected.

Hope this helps.

 

[Foggy]

Thanks Ron.

I take your point about selecting a gear that would allow me to corner without stopping/slowing. If I wanted to take my long runs at a reasonable clip and slow down for the corner without stopping, I assume I need to learn how to double clutch?

I guess the other option is to ram it into a lower gear and collect the gear schrapnel later

Cheers, Foggy

 

[Pauly]

I thought that the finish mower required 1000 rpm????? The 2 stage clutch for turning ....(won't slow down the pto)

 

[Foggy]

Thanks John

I'm getting a bit concerned about the amount of stopping I might need to do to adjust ground speed. Maybe I need to look for a tractor with a synchro tranny, or learn to double clutch

Cheers, Foggy

 

[MarkNHow]

I have a Jinma 284 but it is not a shuttle shift. I mow in High -High 1st gear. When mowing I can make 90 degree turns while maintaining the same speed.

I would get a 6' finish mower for the 284 instead of a 5'.

Mark

 

[billbill1]

I mow in low/3rd and can take 90 degree corners without slowing down, I usually take wide turns and just keep on going. I don't have many obsticles or trees in my yard so it might be different for you. These steer so easy that turning isn't a problem.