John deere 855 tractor yanmar 3tn75rj engine rebuild help

[woodtractor1]

Hi everyone,
I bought a non-running john deere 855. Probably around a 1990.
I got it started once after about an hour of cranking and (last resort) a shot of ether.

I tore the engine down and piston rings had .270" end gap in the rings! (.015" max recommended).

Cylinders are out of round with a large ridge. I didnt think I can get by with .020" over rings so I decided to buy a rebuild kit off ebay and it came with sleeves.

I don't see any clear evidence that this engine has sleeves in it. Does anyone know if this engine has sleeves or not? Has anyone overhauled this engine before? Is there a newer model replacement engine that will fit this tractor?

I am thinking I may have to have the new sleeves bored into the old block, any thoughts??

Thank you so much!

 

[beenthere]

:welcome: to TBN
Don't have answers to your questions, but am interested in following along. There are others better experienced that will offer help if they can.

 

[jd3020u]

I rebuilt one of these a few years back. No wet replaceable sleeves that I'm aware of. Have someone measure if 0.020 will clean up if you can't. I can't answer if there is enough material to dry sleeve it and have std pistons without making a mess. Are the pistons in your kit the same size as your originals? Bought a waterpump for a X495 off ebay once, you wouldn't believe how many applications there are for that motor, all with different pumps and no way to tell what's different. Saved some money but spent way to much time making "alterations".
The early 855 I bought had something with the air filter housing that allowed it to dust the motor, can't remember the specifics but check inside canister for a dust trail. It only had 600 hrs. I spent about $900 for parts and machining (bored it).

 

[woodtractor1]

Jd3020u. Thanks for the reply.
This tractor only has 430 hours! Engine is trashed for such low hours.

I dont think we can net .020". We measured .016" already before boring the cylinder. I'm going to have the machine shop bore the liners into the block. The rebuild kit has standard pistons and rings.

The china rebuild kit had some parts that do match originals but the connecting rod bearings and main bearings are the wrong size.

 

[jd3020u]

That's cutting it pretty close. How much oversize is the OD of the sleeves? Here's a link to a service manual if you need...

http://storage13.fermer.ru/2011/06/182771/dvigatelya_yanmar.pdf

 

[woodtractor1]

Thank you, yes that is the manual I've been referring to. Very helpful to have for sure.

79mm is the OD of the sleeves.

 

[shooterdon]

I have a manual. PM me if you are interested in it

Nice little machine...enjoy it

 

[woodtractor1]

How do I send a pm?

 

[California]

You might also make an appearance over in the Yanmar forum here. One of the enthusiasts there may have experience with that engine.

Is that the same engine as in a JD 850? If so it has a twin under the Yanmar banner.

 

[beenthere]

How do I send a pm?

Click on that persons' user name, and then click on Private message... and send.