1978 John Deere 850 Project

[wct097]

Engine is open, pistons are out. This is what I've found.

#1 cylinder sleeve wall is cracked or corroded:

#1 piston looks decent but has a broken oil scraper ring and two of the three other rings are stuck. Shows some vertical wear, but not sure if that's an issue.

#2 cylinder sleeve looks OK visually, might be able to hone it

#2 piston is dirty, but has no visible wear. Oil scraper ring is broken.

#3 cylinder sleeve has several vertical wear marks. Not sure if it can be honed.

#3 piston shows very noticeable vertical wear marks.

Timing set looks good. A little crud on the cam gear. Coolant hose was full of some sort of crud.

Injection pump was a royal pain to get out. The throttle/governor connects to the pin sticking up at the bottom of the picture. That's connected to a bar that slides side to side. The governor is connected to the pin with a collar and cotter pin that is almost impossible to get to inside the engine. That's stuck on mine and the pin/bar was impacting the side of the case when I tried to pull it off. I had to take the timing cover off the engine to get something in there to tap it back to the center. So that's a problem, I'm sure... the spring that moves it isn't super powerful so I think that should move pretty easily. Likewise, the three rollers that ride on the camshaft are spring loaded. Note the middle one stuck in.

Next step is to take it to the machinist to have the #1 sleeve removed and the block
& head checked for cracks.

 

[GPintheMitten]

I hope you can make it work for you.

 

[jenkinsph]

I see where Deere wants $328 per cylinder for pistons rings and liner. I would check an engine parts supplier to see if you can get these parts cheaper. If so I would consider changing all three out. If I am going to rebuild an engine it would be better to renew all three at once.

 

[Ed of all trades]

I will be watching and wishing I had a project like that. Looks like fun to me. Hope the block is good. Ed

 

[R Barger]

I see where Deere wants $328 per cylinder for pistons rings and liner. I would check an engine parts supplier to see if you can get these parts cheaper. If so I would consider changing all three out. If I am going to rebuild an engine it would be better to renew all three at once.

Hoye tractor has them in the $250.00 range.

 

[wct097]

This is what I'm finding at Antique Tractors - Yesterday's Tractors : Parts and Online Community

Piston (CH10355): $79.13
Rings (CH12046): $27.96
Sleeve (CH13597): $118.21

Total: $225/cylinder for everything

Haven't called my local dealer, but they came in comparable with some other sites I've searched on other parts.

I have no idea what the machinist will say for cylinder 2 & 3 or for the pistons in general. I figure at minimum, I'm replacing sleeve #1, piston #3, and all three sets of rings. I lean towards replacing with new parts, but it really depends on the big picture. I'm not going to spend $3k refreshing the engine on this tractor. My upper limit is in the $1800 range.

I think this is right for some other misc items
Crank bearings (2x) CH10338 ~ $38/ea
Cam bearing CH14887 ~ $33
Rod bearings (3x) AM875927 ~ $22/ea
Rod bushing (3x) MIU801273 ~ $6/ea

I'm thinking parts wise, with gaskets and a new water pump, I'm looking at a minimum of ~ $550 up to about $1200. Don't have a price on the work or the injection pump rebuild yet. One of the two machinists I spoke with quoted me under $100 to inspect the block and head for cracks to determine if it's even capable of being rebuilt.

 

[wct097]

Got the fuel injection pump loosened up and partially disassembled. Tool the roller/pistons out and cleaned everything up. Have the pump body soaking in ATF overnight and expect I can get it back together and functional without an actual rebuild.

 

[2458n]

Well you do have a good deal of work ahead of you. Same tractor with loader came out of a barn in Tipp City Ohio in March. 5600 hours selling due to a divorce. 4800.00 bought it with a 10% buyers premium. Same man bought the tiller for 1200. So for 6600.00 he was down the road. When looking at Tractorhouse before the sale it seems like the tractor sold for 14000.00 new. Good luck with your project

 

[wct097]

Just an update here. Ended up doing a complete rebuild. New sleeves, pistons, rings, bearings, etc. I think my rebuild cost is about $2k with parts, machine work, new water pump, new muffler, fuel filter assembly, and inner combustion chambers. I cleaned, disassembled, and reassembled the injection pump. I think it will work but won't know until I can actually test it with fuel on the tractor. Two of the three injector nozzles were stuck. One took considerable effort to free up, but seems to be in working order now. The injectors were stuck fast in the head and the machinist had to beat them out from the inside which damaged the inner precombustion chambers. I've replaced those. Hope to button the engine up tonight and try to get it back on the tractor Friday, weather permitting.

Assuming I get it running, the tractor still needs some work, but I'll have a running tractor with basically a brand new engine for ~ $3k invested.

 

[wct097]

I got the engine back on the tractor on 7/9, but ended up fighting fuel system problems all day. Got it to run a couple times but ultimately pulled the fuel pump and took it to a localish diesel shop that rebuilds them. Diagnosis was that the pistons in the pump were severely worn. Rebuild cost was north of $700, so I ended up ordering a new pump from Hoye Tractor. Hopefully get it running next weekend.

So this tractor is really a shining example of a "basket case". Not only did I have to address engine internals, but also worn/damaged fuel system components, and found that the previous owner had possibly damaged the fuel pump check valves by removing them and reinstalling them incorrectly. I'm still expecting to need to replace hydraulic lines and it wouldn't surprise me to need seals replaced in the hydraulic cylinders. By the time I do that, and replace the rusted out seat, I'm probably going to be into the tractor for $4k, including the purchase price. Still not bad, but more than I'd hoped to spend. On a positive note, I've got basically a zero hour engine that will probably outlast me if I keep the fluids and filters changed. I also bought one of the exhaust flappers from Tractor Supply. I won't be letting any rain get in there. Learned that lesson from the PO's mistakes.