On-the-fly 4wd?

[George_Martin]

With all the wet weather that we have been having lately, I have been using 4wd quite a bit on my Jinma 284. I know that it should only be in 4wd when needed, so I take it out when back on dry ground. I have found though, that I can take it out of 4wd very easily without stopping or without using the clutch, even under load going up hill. Does anyone else have any experience doing this, going in or out of 4wd?

 

[George_Martin]

With all the wet weather that we have been having lately, I have been using 4wd quite a bit on my Jinma 284. I know that it should only be in 4wd when needed, so I take it out when back on dry ground. I have found though, that I can take it out of 4wd very easily without stopping or without using the clutch, even under load going up hill. Does anyone else have any experience doing this, going in or out of 4wd?

 

[CSH]

I have pretty much the same tractor (Farmpro 2425) with a Koyker loader. I can shift on the fly when the RPMs are below 1900 or so and there's not too much weight over the front tires. I don't force it, so if it doesn't want to engage while rolling I stop and use the clutch.

 

[CSH]

I have pretty much the same tractor (Farmpro 2425) with a Koyker loader. I can shift on the fly when the RPMs are below 1900 or so and there's not too much weight over the front tires. I don't force it, so if it doesn't want to engage while rolling I stop and use the clutch.

 

[RonMar]

You don't need the clutch to shift the 200 series Jinmas in and out of 4WD and it can be done while rolling. In fact, it helps to be rolling to engage it. The front drivetrain is coupled to the rear using two parts called "Claws". The Claw looks kinda like a 6 piece pie with every other piece removed(Nuclear radiation symbol).

The forward claw slides on it's shaft moved by the 2/4WD lever and mates with an identical piece. The teeth on the claw are square faced so will not mate when the parts are not aligned. When rolling, the two parts will typically rotate at slightly different speeds, so holding gentle pressure up on the lever while rolling will allow the parts to align and once aligned will slide into place. This difference in rotation is why you should not use 4WD on solid ground as the wheels need to slip slightly on the ground to keep from wearing/binding/breaking parts in the 4WD drivetrain. This also explains why 4WD does more damage to lawns and such. Sometimes the drivetrain forces the wheel to go faster or slower than it is traveling over the ground so the tread slips/digs in.

The clutch makes no difference as far as 4WD is concerned. The front claw is connected to the front wheels which are solidly on the ground and the rear claw is on the front of the lower transmission shaft that runs directly to the rear differential/axel which is also solidly on the ground.

 

[RonMar]

You don't need the clutch to shift the 200 series Jinmas in and out of 4WD and it can be done while rolling. In fact, it helps to be rolling to engage it. The front drivetrain is coupled to the rear using two parts called "Claws". The Claw looks kinda like a 6 piece pie with every other piece removed(Nuclear radiation symbol).

The forward claw slides on it's shaft moved by the 2/4WD lever and mates with an identical piece. The teeth on the claw are square faced so will not mate when the parts are not aligned. When rolling, the two parts will typically rotate at slightly different speeds, so holding gentle pressure up on the lever while rolling will allow the parts to align and once aligned will slide into place. This difference in rotation is why you should not use 4WD on solid ground as the wheels need to slip slightly on the ground to keep from wearing/binding/breaking parts in the 4WD drivetrain. This also explains why 4WD does more damage to lawns and such. Sometimes the drivetrain forces the wheel to go faster or slower than it is traveling over the ground so the tread slips/digs in.

The clutch makes no difference as far as 4WD is concerned. The front claw is connected to the front wheels which are solidly on the ground and the rear claw is on the front of the lower transmission shaft that runs directly to the rear differential/axel which is also solidly on the ground.

 

[George_Martin]

Thanks Ron. I was afraid to try to put it into 4wd without stopping and clutching. So I guess that just before coming to a really wet area, that I know I will need 4wd, while all wheels are running at about the same speed I can engage the 4wd without any damage the the drive train.

 

[George_Martin]

Thanks Ron. I was afraid to try to put it into 4wd without stopping and clutching. So I guess that just before coming to a really wet area, that I know I will need 4wd, while all wheels are running at about the same speed I can engage the 4wd without any damage the the drive train.

 

[greg_g]

</font><font color="blue" class="small">( Thanks Ron. I was afraid to try to put it into 4wd without stopping and clutching. So I guess that just before coming to a really wet area, that I know I will need 4wd, while all wheels are running at about the same speed I can engage the 4wd without any damage the the drive train. )</font>

Correct. And the same operating principle applies to the rear differential locking mechanism (diff lock) as well. It needs 1/4 to 1/2 revolution of the rear wheels to positively engage.

But these "dry surfaces" to which you refer essentially include only concrete and asphalt. I generally keep my 4wd engaged 24/7, as the tractor is used primarily on pasture, in woods, and over gravel farm roads. I only ensure that I'm in 2wd if I have to get up on the highway to go to another farm.

//greg//

 

[greg_g]

</font><font color="blue" class="small">( Thanks Ron. I was afraid to try to put it into 4wd without stopping and clutching. So I guess that just before coming to a really wet area, that I know I will need 4wd, while all wheels are running at about the same speed I can engage the 4wd without any damage the the drive train. )</font>

Correct. And the same operating principle applies to the rear differential locking mechanism (diff lock) as well. It needs 1/4 to 1/2 revolution of the rear wheels to positively engage.

But these "dry surfaces" to which you refer essentially include only concrete and asphalt. I generally keep my 4wd engaged 24/7, as the tractor is used primarily on pasture, in woods, and over gravel farm roads. I only ensure that I'm in 2wd if I have to get up on the highway to go to another farm.

//greg//