4 wheel drive

No, there's not a shear pin.  The front drive shaft is connected to the output from the transfer case by a few ball bearings engaging grooves in the shaft and receiver.  Your parts book should show it.  The balls are retained by a cover that is held in place with a spring clip.  Sometimes the spring clip fails or slips and then the receiver can shift, allowing the balls to fall out – no four wheel drive after that. 

When you remove the rubber cover on the front drive shaft, do it on a smooth floor or a tarp or something so you can find the little balls when they drop out.  Then all you have to do is reassemble the thing with the balls in place – some very stiff grease will hold them in place while you get things back together.

It may require that yo un-couple both ends of the front drive shaft to remove it.  I had to do that on my JM304 in order to get the clearance to force it out.  Yours may be the same.

Hope this helps.

Rich is correct,most of the time the Snap ring breaks which allows the balls to fall out,you should have 6-ball bearings for each end of the shaft

Tommy

Affordable Tractor Sales

“Your Jinma Parts Superstore”

http://www.affordabletractorsalesco.com

Just wondering, do you nomally run it in 4WD? Or use the loader while in 4WD?

My operating hours, nearly 300 HRS,  are almost alway on dirt, in the woods, plowing snow, etc. so it's always in 4WD, except for special circumstances with a full bucket backing uphill or anything else I've read online that can lead to front drive failure.  I work it hard but at the same time, I'm careful.

I am haveing  a problem, or not,   jinma 204 290 hours my 4WD lever is stuck enguaged in the 4WD position the drive is working,  operated on dirt most all the time and taken out of 4WD on pavement, but in this instance it would not desenguage, and I did not enter the pavement, I do not want to force the lever and break something but it is stuck firm in 4WD, any one got any ideas 

Squirt everything involved with a mixture of half and half acetone and Automatic Transmission Fluid (ATF), or use WD-40.  Let it sit overnight and then take a small hammer and tap everything several times until it loosens up – don't wail away on it with a big hammer, just tap it to vibrate it loose.  The odds are the linkage just has developed a bit of rust that is making it stick.

You may also need to try rocking it forward and reverse with the clutch while applying pressure tot he lever.

I suggest that you not use 4whl drive unless you need it. Every turn puts a strain on the drive train while in 4whl drive. If you find yourself slipping pull the lever into 4whl drive and when not needed take it out. 

When I first got my 2001 tractor the balls came out. I found the snap ring groove was not machined deep enough so I machined it out. I have not had that happen again and I have used 4whl drive rather hard at times. 

I think a lot of issues on levers not moving is because they are not used for long periods and will stick from corrosion. However, there may be something broken inside so don't force anything without trying to find the problem. The 50/50 mixture of ATF and Acetone is the best penetrating oil you will ever find but mix only what you will need or keep it capped to prevent evaporation of the Acetone.

I will try that. It makes sense that the lever is just stuck, I grease every thing else. The tractor is in  salt marsh acreage and needs to be in 4WD almost all the time with the AG tires on, Mowing in the summer I change to turf tires remove the loader and do not need 4WD as the rears are wuch wider.

On the 4wd not working, most of the time it is the circlip broken or slipped out of groove on shaft, we had one in the shop today with same problem. Circlip had slipped out of groove on shaft allowing the 6 steel balls to come out of coupling. You will know when you drop the cover under tractor, look for steel balls to roll out! We have every part in stock for your tractor if you need something.

Ben

http://www.circlegtractorparts.com