841 Diesel Cam

[mattthew blevins]

Well, Today I took the front cover off my 801 diesel engine, and the main cam gear was in several pieces and the crank gear was mauled on one side and the gear for the hydraulic pump was mauled in one area (gears sheared off). The pump turns free and the gear is O.K. but it has some movement on the shaft that makes me wonder if a keeper is missing, or something of that nature. I compared it to another that did not move from side to side on the shaft as this one did. I don't think it broke the cam shaft though, it has solid movement to it from the main gear to the pump gear and leads me to believe it is O.K. But I will double check it to be sure. I have still got to brake the tractor apart. I haven't got all my hay up yet. I have taken my last week of vacation to get things done. Seems like my baler equipment is wanting some attention too. Wouldn't you know it. It doesn't let you know it needs something till the hay is on the ground and their calling for rain the next day. Things have been somewhat stressful here in Alabama this week. I will have to go back to work to rest. Ha Ha. I will say that it is a blessing to have two tractors (Ford 3230 4x4 and a 861 Powermaster) that are running. Anyone got any suggestions on the 841? I know how all this works but I am not against anyone telling me anything, that has had experience. Thanks

 

[Anonymous-0]

Oh what a mess!! It would be best to take the engine all apart and do a complete overhaul. You most likely have metal everywhere in the system. Pull the oil galley plugs and clean and brush them out. Measure evreything to the book and go from there. You will have a few bucks in it, but in the end a good tractor. Now here is good advice. Diesel crankshafts are getting hard to find. It is not reccomended to grind them. You can polish them down a few thousands and install bearings that are .001-.003 under size. Since you have had all these metal shavings going through the oil system you may have some grooves in the crank. As long as it measures out O.K. you can live with a few grooves.

 

[Anonymous-0]

As for the hydrualic pump. Go completely through it and make sure the relief valves are working. You have a good winter project. We all love a good challenge!

 

[Anonymous-0]

Before I go --- I forgot to mention. Change the cam shaft. It may be straight but it may have a TWIST in it. From experience I can tell you they do not run well with a twist in the cam!

 

[larryd]

Matt
I think your cam & gear failure was caused by the hydraulic pump.
I have seen this happen three or four times
all hydraulic pump failures.some would turn the shaft would move in & out,the pump would lock up at some point.
Had a 861 Diesel do this to me one time
new front gears cam Hydraulic pump & gear was needed.
need more info eMail me.

 

[john_Bud]

This is from a distance and may be different up close, but...


I would pull the cam and replace it, pull the tappets and have them ground to match to the new cam. Definitely clean the oil pan and check the bearings for damage. You probably (fingers crossed!) don't have any damage from the chips as the oil filter should have caught the debris. (should have!). BUT, the oil pump may have taken a hit. Check it close and replace if it is suspect. $50 is cheap compared to low oil pressure. I also like to pressure wash the coolant galleries to blow out the accumulated crud. An amazing amount of "stuff" always comes out from sand to metal chip, old gasket and even mouse parts.

I think you will have to hit the used market for the crank gear and the 2 cam gears. You can look the parts up online at www.external_link Look around for the FNH parts link. They have prices and delivery estimates and have been good to me in the past.

The hydraulic pump MUST be taken down and rebuilt. It's a 99.999% sure bet that it was the root cause of the problem. You really don't want to have this occur 2x.

jb

 

[RBnSC]

I think I would check some valves. There isn't any combustion chamber to hide in when the cam stopped turning and the crank didn't.
Ron

 

[mattthew blevins]

Thanks for all the suggestions, and I did buy that old 601 diesel with the slung rod. I have inspected it and all looks good except of course the hole in the block. So, with that in mind what do you fellows think I should do, replace the cam match the valve tappets or use the tappets out of the 601 and not worry about it?

 

[john_Bud]

(quoted from post at 17:33:38 10/03/09) Thanks for all the suggestions, and I did buy that old 601 diesel with the slung rod. I have inspected it and all looks good except of course the hole in the block. So, with that in mind what do you fellows think I should do, replace the cam match the valve tappets or use the tappets out of the 601 and not worry about it?

Well, either way will work (most of the time). As long as you keep the tappets with the exact same cam lobe, you "should" be ok. Now they may be worn and may need a grind. You will have to inspect and see. It's cheap to have them surfaced, but it's your money.


I would grind them, but for me the effort of not having to re-splitt the engine is worth the expense.

 

[Matthew Blevins]

O.K. Thanks John.