51 John Deere A engine

Can you access the bolts for the piston rods with the block on the tractor?

Naturally there is a access cover right over top of the ROD CAPS , if you LOOK.

Matt,

There is a cover on top of the main case from which you can gain access to the crankshaft and rod caps. Various oil lines will also be accessible. You will have to rotate the crankshaft to get first to one cap and then the other. Be sure to pull the plugs to make the engine won"t start.

Kurt

get a manual! its obvious you will be greatly helped by one. worth every penny!

Thanks for the helpful reply, Kurt. I have ordered an IT manual, but it has not arrived yet. This is my first go at a 2 cylinder. I haven't worked on anything smaller than a 3020 up to this point. It appears to be in worse shape than I expected. The engine and the clutch are both stuck. The sheet metal, on the other hand, is almost perfect.

Try not to be so nasty Carlyle.

Matt,

It can be a bear to get the engine apart if you cant get it unstuck. Start by pouring some auto-trans fluid in the spark plug holes and let it soak for a week. If you can't get to move with reasonable force, take the head off and see what the cylinders look like.

If you can get the rod caps undone, it is possible (maybe) to pull the block with the pistons and rods stuck in it, depending upon the position of the crank.

On my stuck '38 B I had to also remove the main bearings from the crank so I could shift the crank back enough so the rods would drop free of the crank. I could the pull the block.

If you get the block out this way, you can then press out the pistons or set the block up on some wood block, put a block of wood on top of the piston and pound it out.

Good luck and be sure to post back.


Kuert

Soak the pistons with Diesel/Trans mix. While that is happening remove the clutch and belt pulley. You may have to pull the cover that the belt pulley slides into (First reduction gear cover) off if the pulley is rusted fast to the dust shield as mine was. I got the guts of the clutch out and my pulley still wouldn't turn due to the dust cover. My clutch was stuck engaged as well. You can also go to JDparts.com and download the .PDF parts catalog. It can help you when figuring out what parts there are. Its free too.

If you need help feel free to ask.

Good luck.

You can remove the flywheel cover and use a Come-A-Long around the flywheel, to the front frame and encourage the engine to move...
May need to leave pressure on for a while and reverse it, to help get the penetrant to soak better..
With the block in the tractor, you could even add hot water to expand the block a little, after the come-a-long is set up and the cylinders have soaked a week or 2..
I prefer Automatic trans oil, mixed with kerosene, or mineral spirits..
Not all "Stuck" engines should be expected to
Come loose...
Ron..

Thanks for ALL of the replies. I have removed the head and everything looks good from that end. I will continue to soak the cylinders and start applying pressure to the pistons this weekend. Hopefully the bottom end is in as good of shape as the top. One additional question on the clutch. With the clutch stuck engaged, should I be able to remove the inspection cover including the linkage and clutch fork? With the cover loose, I cannot remove the fork at this point. Thanks again.

I'm not sure what you mean by inspection cover unless your talking about the flat cover on the belt pulley itself. The clutch fork/pillow block is at the front of the cover that the belt pulley slides into. (First reduction gear cover) If it is stuck engauged you don't have much of a chance of getting the clutch fork out. The bronze collar that works the clutch sleeve will hit on the inside of the first reduction gear cover.

Have you taken the clutch apart in the belt pulley yet? You will need to take off the 3 castle nuts and remove the adjusting disk. (outer most piece). Make sure you get the Facing out of there. Then you will have to pull the Drive disk next. This may be a bit difficult but it will come off. Its like pulling a timing gear off of the crank shaft on a V8 chevy engine. You need to make sure that all of this stuff is loose before you pull the first reduction gear cover. The Drive disk needs to be off of the crank shaft before the belt pulley can come off anyway. In a perfect world with the clutch fork out the belt pulley would just slide off.

If you can not get the clutch lever to move the fork at all, most likely the clutch sleeve is rusted fast to the inside of the dust cover. I had to take the reduction cover off with the belt pulley in it and then I heated from the inside on the dust cover and worked the linkage until the clutch sleeve pulled back.

If the Clutch lever works then its possible that the belt pulley is rusted fast to the outside of the dust cover. A little bit of heat and tapping with a hammer to 3 inches or so on the surface of the pulley at the reduction gear cover side will/should loosen this up.

I have some pics of this if you need them.

Thanks for the tips! The clutch lever will not move the fork. I will work on removing the clutch while the pistons are soaking.

On my late A I used a 5' pry bar on the flywheel. (after pulling the head and soaking in a penetrating concoction) The pry bar fit nicely with the tip of the bar behind the cast balance weight section of the flywheel and using one of the hub bolt heads as a fulcrum. This leverage applies massive, smooth, no impact, rotational force on the crankshaft. It freed a very tightly stuck engine.

HTH

Mark

I tried to use a pry bar on my 60 flywheel and cracked the flywheel, that old cast is real brittle. Seems to me the rocking the rear wheel while in 6th gear is safer and that’s how I got mine loose after messing up the flywheel.

Deerly Departed sells JD manuals, they are alot better than the IT manual(cost more too) get the shop and owners manuals. many have mentioned "downloading the parts manual, i was unable to do this and wound up buying a parts manual also. the purchas of said manuals is the best money you can spend on your tractor

Ok, we've got her down to bare bones. I split the tractor over the weekend and pulled the block. The pistons are still soaking, but there was a lot of rust on top of the pistons. One of the valves was open which must have allowed 20 years of weather to enter the cylinders through the holes in the manifold (no pitting,just flaky surface rust). The bottom end looks pretty clean except for about 2" of sludge in the sump. Still working on breaking the drive disk loose on the clutch. I'll let everything soak for a few days and try it again.

(quoted from post at 06:10:38 12/07/09) Still working on breaking the drive disk loose on the clutch.

Click to expand...

In the manual it says you can remove the drive disk by putting two bolts with nuts on them in the slots on the drive disk and turning the bolts in against the belt pulley and it would push the drive disk off. I'm not sure how you keep the nut from turning on the back of the drive disk since the you can't get a wrench in there.. If you have a high lift jack you could do what I did. I put two bolts in the slots in the drive disk and through my high lift jack. I then put a piece of all thread into the end of the crank and through the high lift jack with a washer and a nut against the high lift jack and then I just used the nut on the all thread to pull the drive disk off. I'm sure there are other ways but this is what I had to do this with.. I also heated the drive disk also. I'm not sure you will really need to do this though..