Replace or Repair Cracked Oil Pan Jinma 284

I'm not familiar with the 200-series Jinmas, but on my 304 Jinma, you have to split the tractor in order to remove the oil sump.  So it gets to be a big job.  Not really all that technically difficult, but time consuming and requires care and patience.  Also, the sump is part and parcel of what constitutes the “frame” of the machine, so I wouldn'’t try to repair it.  I’d replace it with a new piece.  Repairing castings is a dicey business and when they are subjected to stress there is a high likelihood of failure.

The 200-series may be different than the 300-series and the sump may drop right off – I don't know.  If it does, then it isn'’t part of the structural members and could possibly be repaired by careful brazing.  I wouldn’'t try to weld it as you’'ll have too much weld stress and it will likely crack again in short order.  Brazing is much more forgiving and is the standard method for most casting repairs.  Pre-heat and post-heat are still important – get it up to 400°F before you start and keep it at 400 for a half hour or an hour after brazing.

Either way, you need to start by trying to determine why the thing cracked in the first place.  Was it installed in such a way that it was put under stress when the bolts were tightened?  Was it a defective casting?  Did you hit a rock with it?  My sump is a heavy casting that would be unlikely to crack easily, so I'd want to figure out why so the next one didn't do the same thing.

Good luck with it!

I would not take a chance on welding the cast iron oil sump up, if it leaks and you run out of oil you just cost yourself a engine.If you have the 1- piece sump, you will have to split the tractor to replace it. I would replace it with the newer 2- piece sump with a bottom cover, that way next time you need access you don't have to split the tractor

We have all the parts you may need, splitting the tractor may be more than you want to do.

Tommy

Affordable Tractor Sales

“Your Jinma Parts Superstore”

http://www.affordabletractorsalesco.com

Have to agree with Tommy.  The price of the sump/oil pan is the easy part.  It's time consuming to split the tractor, but it's pretty straightforward, provided you have the means to support the back half, while suspending the front half/engine.  I can make guesses as to why the pan/sump cracked, but who needs speculation.  Get the parts on order, and then get after getting them replaced.  Look carefully at everything as you take it apart, to see if you can pinpoint what caused the failure (loose or broken bolts for example).  Replace any bolts/nuts that look even slightly questionable.  And when you put it back together, be certain everything is aligned properly and then bolted securely. 

You said you tried JB Weld. I assume the basic JB Weld that comes in two squeeze tubes. There are other repair materials that are more of a putty. I believe what I have used is called PC something. JB Weld may also have a putty. The putty stays in place and doesn't run. Insure the surface is free of paint and is clean. I use a paint deglossing fluid that does a good job of removing any surface oil. If you have access you may also rough the surface.

A couple of tips if you're going to split your tractor:

Have a digital camera handy before you start and photograph everything in place before you remove anything. 

Label everything with tape and a pen.

Remember that the front axle toggles and block it on both sides so the front half doesn't tip sideways when it is loose from the rear.

Work on flat surface so it is easy to roll the rear half back when loose.

Use plenty of cribbing to support things – don't take chances.

Torque every bolt correctly and use new bolts where there is any question.  Loctite blue is a good thing, too.

Get all new gaskets – don't reuse old ones no matter how good they might look.

Replace the throwout bearing and pilot bushing while you're in there and also the roll pin(s) in the clutch actuator fork.  Use two nesting roll pins to be sure they won't shear off later.

There are at least three different oil pans used with this engine so I may be wrong, but most of the time to take the oil pan off you have to split the engine from the transmission.

A tractor has no frame, the engine is the connection between the front wheels and the rear wheels, and it takes the full weight of whatever you are doing. On a Jinma the oil pan is where the front wheels connect to the engine and it is a weight-bearing component.

I'm going to speculate and say the reason your pan cracked was because your mechanic didn't use the right gasket. When it was put under load the sealant yielded and the pan flexed and cracked.

Anyway, you need to replace the pan. It costs about $125, I see no sense in fooling around given the amount of labor involved.

Detailed instructions for splitting my 354 are here, starting at post #19:

http://www.tractorbynet.com/fo…..low-2.html

It's not the same tractor but it's very similar, certainly the same general idea.

The second time I split my tractor I did the whole job in a single day, experienced mechanics seem to think 6-8 hours. So that should give you an idea of the magnitude. Nothing in it is more complicated than replacing a starter or hydraulic pump, it's just a whole day of loosening bolts and tightening them again. 

It's your tractor and you are the only one who can actually see what is going on with it, how bad the leak is, etc.  Having said that; If that cracked part gives way completely under strain of the farm work you do with it, while under load, out in the field and you don't notice it quickly enough to shut the engine down, ………………   IMO, the time and expense to tear it down and replace the defective part (approximately a day, to a day and a half), versus the expense of a complete failure, loss of use of the tractor for however long it takes to drag the carcass to the shop, evaluate the damages and order the parts, wait time for parts delivery and then performing the repair……….  That also assumes the mechanic will be immediately available to work on your tractor when the total failure takes place.  Are you feeling lucky?

As to the other question; You are within your rights to ask questions.  How much you value the availability and good relationships with your mechanic, will determine how your questions are asked, or if asking them are worth the possible damage to the relationship.  If he hasn't already offered to help out with a proper repair, based on what he should already know, then I would question his reliability.  That's just me, standing in the hall, looking in the door.  You know your circumstances and the alternative availability of other mechanics, better than I do.  I also know, from personal experience, pulling te tractor down myself and doing the repair myself, would probably be my first option, because I have alread successfully done so.  But nobody can make those choices for you.  Either way, I hope it all works out well for you, whatever you decide.

I think the answer as to whether you can keep working with the pan cracked depends on the kind of work you have to do.  The oil sump is not under any pressure, it just holds the oil after it drips down out of the engine, until it get sucked up by the oil pump. Chewing gum or duct tape would probably keep oil from seeping through the crack, if you could get it to stick. We've probably all run engines that leaked “a little” oil, as long as you keep an eye on it and don't let it get too low it shouldn't be a problem. 

A bigger issue, as rdstevens alluded, is that the pan is weight-bearing. If it were to crack completely and lose all of the oil while running, that could be very bad. When using rear attachments it doesn't take much weight. But if you're lifting something heavy with the front loader pretty much the entire weight of the tractor, plus whatever you're lifting, is borne by the front wheels — and the oil pan is the attachment point for the front wheels, so it's bearing that weight. 

I agree with what QSF and RD said.  The oil leak is the least of the issues.  The more significant issue is that of overall physical integrity of the tractor's structure.  The oil sump is part of the structure and if it were to have a catastrophic failure (break in half), the load that it bore would be transferred to the bellhousing, very likely resulting in a failure at that point as well.  Bad juju – would not only mean splitting the tractor but replacing the bellhousing, oil sump and maybe a destroyed engine if you don't notice the loss of oil pressure immediately and cook the engine.  

Were it mine, I'd order a new oil sump and the requisite gaskets and replace the thing now.  It is your choice, however.   Hell, it might be much less serious than I'm imagining – I can''t see the crack so I can't say whether or not I'd take any chances on it.  But the previous use of a non-OEM gasket would make me nervous that it was cracked due to uneven pressures when installed and that could bite you in the hindquarters later.

my 2 cents are not worth much but why would this happen.the oil pan has many bolts that transfer the load to the block for strength (i assume).could there be a non straight milled edge that when the pan was torqued over stressed the pan and cracked it? and with that thought,the gasket would have to be thin and hard. a thick gasket soft would distort easily causing uneven pressures.just a thought

I've got a 2005 284 with the Yangdong  Y385T engine.  Visually, it appears that te oil pan ( or at least the bottom of the oil pan ) does not have any connetion with the tractor frame. The bottom of the pan, the “oil sump motherboard” Part NO. Y380T-01705, and its gasket, PN Y380T-01706, appear to be easily removable.  You may take a look at your pan, and if the crack is in the bottom of the pan, the motherboard, it maybe easily removable ( 10 bolts and washers, PN GB/T5783-2000, M8X 22, and washers NO. G848-85 ). 

Based on the drawng, the oil sump, ( the oil sump forms the sides of the oil pan, the mother board seals off the bottom ) PN Y385T-1-01701, and gasket, PN Y380T-01018, may also be easily accessible ( unless your tractor carries as much grease and oil around with it as mine does).  Take a ood look with a flashlight up under the engine and see if the bolts are visble and can be removed easily.  The repair may be easier than you think, and you may not have to split the tractor.

If the job requires splitting the tractor, I would seriously consider going to a shop that knows how to work on Jinma's.

Bob   

According to Tommy from Affordable Tractor, if the oil sump is the one-piece design (without the removable bottom plate you call the “motherboard”), the tractor has to be sllit to replace the sump.

I know that on my 304 Jinma there are three or four bolts that go through the flywheel cover and into the back edge of the oil sump, so there is no way to drop the sump without splitting the tractor and then removing the flywheel to access those bolts.

I can't address the 300 series.  On my 2005 284, the motherboard, which is the bottom of the oil pan, is  removable from below.  It sits right above the drive shaft for the FWD.  About 20 bolts holding it to the upper pan,and no attachment to the rigid frame.  Look underneath your tractor and if it is like mine, the repair sequence is obvious.  The oil pan drain plug is in the motherboard.   Frame/engine  attachment is achieved by bolting into the sides of the cast oil sump-which is open on the bottom and sealed by the installation of the  motherboard and gasket.  The motherboard is shallow enough that it looks like it will come off w/o any interference from oil pump, etc.  At worst, the drive shaft for the FWD would have to be dopped for cleaance to remove te board.

If the crack is contained on the motherboard, you could do the repair!

Bob   

Lobster:  In the original post, you say the pan is cracked from top to bottom.  If that means the side of the pan (sump ) is cracked, I would advise you to make a repair posthaste…….because the sides of the sump are the structural component that holds the engine in, and also provides the structural support (spacing)  between the sides of the frame.  If the sump is cracked, the area where it bolts into (up to) the block is in deep trouble.   A broken engne block would be a much wose and costlier repair than fixng the sump.

 I hyope you are talking about the motherboard!!

JM2$W

Bob  

Looks like there's a gasket between the Oil Sump and the Flywheel Housing. Can't see where there are bolts holding these together. Are they inside the Flywheel Housing? Is this why I would need to split the tractor?

The heads for those bolts are behind the flywheel. In order to loosen them you have to split the tractor, remove the clutch and remove the flywheel. A lot of work for a few bolts.

I'm going to try a different way of posting the link. Click Here for instructions. 

It should be the same as http://www.tractorbynet.com/fo…..print.html

Initially I had difficulty finding the oil pan gasket. I eventually took a  picture of my pan and emailed it to Tommy at Affordable and he walked around in his gasket room until he matched it.

Let me know if you have questions, I'll try to answer.

Lobster,

There's a thread I did on splitting my tractor (also a 304 Jinma) on Chinese Tractor World forums.  You can see it here.  There's a goodly number of photos that may be of some help; even though your 284 is a smaller tractor than mine the general process should be the same.

If you run into problems, Tommy at Affordable Tractor Sales is a great source of spot-on advice.

Good luck with it! 

There's a lot of good info in the post that Rich references, particularly the photos give a good idea of what to expect.

In my description, I leave the flywheel housing attached to the engine block, which is the way I did it. Looking back, I would say it would be easier both getting the sump off and back on again if you take the flywheel housing all the way off.