861 diesel problems

MitchellB · Aug 13, 2014

Took the (new to me) 861 out finish mowing yesterday afternoon. Seemed to do good for about an hour. I wasn't even running at full PTO speed on the tach, but about 3/4 (needle straight up) mowing in third gear. I had just finished one small field and had moved to the other portion. Grass was about two weeks since I had mowed last, so thick in places, but nothing that should strain it much. I heard something clank and thought at first the mower had hit something as the engine seemed to bog down. I quickly hit the clutch and took the PTO lever out of engagement and noticed the RPM/Tach had stopped working altogether. The engine seemed to be out of time struggling to run. I limped her back to the shed, although I wasn't sure she'd make or if I should even try. She was beginning to run hot when I shut her down and would occasionally spit out flecks of red hot carbon specks from the exhaust stack just before I got under the shed. My first guess is the hydraulic pump that the RPM cable connects to, but I'm new to diesels, so I'm not sure really what happened. I hope this new 55 year old tractor didn't just die a major death on me. Any advice on where to start or what happened?

Undid the tach cable and it does not appear damaged and turns freely in my fingers. Tried cranking the engine today, but would not fire up. I tried engaging lift (lever up) to see if spinning the engine with the starter would raise my mower up off the ground, but it did not move either. So maybe I have two problems that began at the same instance? Bad pump? (by the way I changed the hydraulic fluid but never used the lift much running the mower yesterday) But why would a bad pump affect the engine? Pull the pump to inspect the gears first? Maybe I need to keep my 8N?

boggen · Aug 13, 2014

MitchellB said:
Took the (new to me) 861 out finish mowing yesterday afternoon. Seemed to do good for about an hour. I wasn't even running at full PTO speed on the tach, but about 3/4 (needle straight up) mowing in third gear. I had just finished one small field and had moved to the other portion. Grass was about two weeks since I had mowed last, so thick in places, but nothing that should strain it much. I heard something clank and thought at first the mower had hit something as the engine seemed to bog down. I quickly hit the clutch and took the PTO lever out of engagement and noticed the RPM/Tach had stopped working altogether. The engine seemed to be out of time struggling to run. I limped her back to the shed, although I wasn't sure she'd make or if I should even try. She was beginning to run hot when I shut her down and would occasionally spit out flecks of red hot carbon specks from the exhaust stack just before I got under the shed. My first guess is the hydraulic pump that the RPM cable connects to, but I'm new to diesels, so I'm not sure really what happened. I hope this new 55 year old tractor didn't just die a major death on me. Any advice on where to start or what happened?

Undid the tach cable and it does not appear damaged and turns freely in my fingers. Tried cranking the engine today, but would not fire up. I tried engaging lift (lever up) to see if spinning the engine with the starter would raise my mower up off the ground, but it did not move either. So maybe I have two problems that began at the same instance? Bad pump? (by the way I changed the hydraulic fluid but never used the lift much running the mower yesterday) But why would a bad pump affect the engine? Pull the pump to inspect the gears first? Maybe I need to keep my 8N?

basic data
TractorData.com Ford Powermaster 861 tractor information
part diagrams and parts numbers
Official New Holland Online Parts Store and Online Parts Catalog for New Holland and Ford Tractors.

the way you describe things, it sounds like engine trouble vs hydraulic trouble.

there better knowledgeable folks than i here on the forums....so will end here...

wmonroe · Aug 13, 2014

Was it making any abnormal smoke (black, or white)? I'm not sure how the injection pump is attached on this model but something sheared and the injection timing is way off. Give us as many details as possible and we can help troubleshoot it, these old diesels are fairly simple.

MitchellB · Aug 14, 2014

I think the answer or source of my problem came to me in a dream last night. After a quick check in my service manual this morning that I just got, this could be a very major fix, as in engine removal to remove cam shaft (if needed). The pump runs off a gear on the rear of the cam shaft. The cam shaft gear runs off a gear in the front. I'm thinking the cam shaft gear, cam shaft or main gear on crank shaft or all three or worse would cause pump, tach and timing problems all to happen at once. I had an old Chevy pickup break a timing chain once and it bent push rods. I may end up doing a total rebuild if I have to split the tractor to pull the engine. I think somebody sold me their problem.

wmonroe · Aug 14, 2014

I would be very surprised if you are having issues with the cam or crankshaft gears. Were you getting any smoke when it was running rough?

Soundguy · Aug 14, 2014

no timeing chain on this model. timing gears. but it's all up front.

injection pump is roosa master and is located where the distribuitor would be on a gasser thus is drive up front.

MitchellB · Aug 15, 2014

I pulled the front cover (over the gears) off yesterday thinking the woodruff key mentioned in the manual that holds in the cam gear in time had sheared allowing the cam gear to spin. I had hopes (being a 1958) that this was the early model listed in the book that is held on by a nut. However this cam gear appears to be the pressed on style with a snap ring retainer that the book says can only be removed by removing engine. Good news seems to be that the gears are not worn or broken and the cam gear and cam shaft appear to be turning together when I crank the starter (marked with grease pencil). A wet surprise was when I removed two of the cover bolts, all my antifreeze began dumping out on the ground, but I was able to catch most of it. I am also unable to get the cover out from between end of crank shaft and pocket shaped front engine mount. That'll be a pain to clean up, gasket and put back together. I'll take some pics this morning that may help.

I'm back to being stumped. I had thought next about pulling off the pump to see if the pump gear on the rear of the cam shaft is turning. Will the pump come off without removing the heavy cast pipe that curves under the engine to transmission reservoir?

The suggestion about removing the valve cover to inspect push rod movement - will the valve cover come off without removing fuel tank? Don't look like there is much clearance there under the diesel lines.

I haven't touch the fuel shut-off since I've had it, because it takes a long flathead screwdriver to turn it. (tight fit between it and valve cover). I haven't seen any "windows" in the block either

I never paid attention to the smoke when I tried to crank it yesterday, so there may not have been much coming out. ??? but I know I had the fuel lever on when cranking, even moved it up higher once.

Thanks for the advice. I'll be needing much more.