All good, you never know about somebody's skill level or knowlege. Keep the advise coming.It sounds like you have done your research. I apologize for inferring that you did not know what you were doing
Good luck with the rest of it. It will run like a top.
D722 complete engine rebuild
- Thread starter TreeFarmer
- Start date
Kuboman,
He had us both fooled.
Saying he was a new-b and stuffing over-sized pistons into cylinders raised red flags all over the place.
No harm, no foul I say.
Better to try and stop a run away train than to just watch it go by.
He had us both fooled.
Saying he was a new-b and stuffing over-sized pistons into cylinders raised red flags all over the place.
No harm, no foul I say.
Better to try and stop a run away train than to just watch it go by.
I'm slow but I make up for it with my inefficiencies
Just a quick update. Finally got the replacement rings (ruined the first set trying to install the piston) for the #2 piston and have installed it and everything is turning smoothly. I did pick up some Plastiguage and checked the crank and everything was to factory specs. I finally took the time to re-clean all the RVT off of the oil pan and that is now re-installed. I also took the time and poured some gas in both the intake and the exhaust ports of the head and the fuel stayed full for several minutes. Obviously some ports/valves were seated better than others, but after 5 min they all were still at least 1/2 full so I will consider this a good thing and no additional work should be needed. I am not going very fast on this, but I do not have any pressing need to get it fixed. Just slow & steady. Although with where I sit now, if I get a day to work on it, then I should be able to button the rest of it back up.
TreeFarmer
Just a quick update. Finally got the replacement rings (ruined the first set trying to install the piston) for the #2 piston and have installed it and everything is turning smoothly. I did pick up some Plastiguage and checked the crank and everything was to factory specs. I finally took the time to re-clean all the RVT off of the oil pan and that is now re-installed. I also took the time and poured some gas in both the intake and the exhaust ports of the head and the fuel stayed full for several minutes. Obviously some ports/valves were seated better than others, but after 5 min they all were still at least 1/2 full so I will consider this a good thing and no additional work should be needed. I am not going very fast on this, but I do not have any pressing need to get it fixed. Just slow & steady. Although with where I sit now, if I get a day to work on it, then I should be able to button the rest of it back up.
TreeFarmer
Hi guys,
i am in the process of rebuilding the same engine- full rebuild from crank up. I have been stumped by the tightness of the connecting rod bearings. I have assembled the engine however cant turn the engine to adjust the valve clearance. During assembly I have been able to rotate the crank when the connecting rod cap bolts are a 1/2 turn out. The crank measures correct for clearance however it simply will not turn over when correctly torqued. I am concerned that the engine will not turn over on the starter motor for the initial fire up.... any suggestions will be appreciated- may assist this thread?
Steve
i am in the process of rebuilding the same engine- full rebuild from crank up. I have been stumped by the tightness of the connecting rod bearings. I have assembled the engine however cant turn the engine to adjust the valve clearance. During assembly I have been able to rotate the crank when the connecting rod cap bolts are a 1/2 turn out. The crank measures correct for clearance however it simply will not turn over when correctly torqued. I am concerned that the engine will not turn over on the starter motor for the initial fire up.... any suggestions will be appreciated- may assist this thread?
Steve
Kubota Newbie
Active member
Equipment
M4500, New Idea Cut-Ditioner, JD 14T Baler, IH "Plow Chief" plows, Oliver Rake
Did you mark the rod caps during disassembly so that they could be installed back on the same rod and in the same relation to the rod? I'm not familiar with those rods, but on many the cap can be reversed accidentally (180 degrees out of position) which will cause the problem you describe. The crank should turn freely with the rod bolts torqued. Also check the part numbers on ALL of your bearing shells to make sure that one of them is not marked undersized.
IF, you've mixed up the rod caps (not marked them). Try them (the caps) one at a time starting on the front journal. Torque it down, see if it is free (you should be able to move it back and forth on the journal when torqued and crank it over freely).
If you're positive the caps arent mixed up and the caps are on in the right direction AND you didn't accidentally get an undersized bearing shell (or half shell). Then take the rods out, torque the caps on and have them checked for out-of-round (but this probably isn't the problem).
Knew a guy that forgot to mark the caps on a V-8 one time. Heh, heh, heh... Took him hours to figure out which cap went on which rod, one at a time.
IF, you've mixed up the rod caps (not marked them). Try them (the caps) one at a time starting on the front journal. Torque it down, see if it is free (you should be able to move it back and forth on the journal when torqued and crank it over freely).
If you're positive the caps arent mixed up and the caps are on in the right direction AND you didn't accidentally get an undersized bearing shell (or half shell). Then take the rods out, torque the caps on and have them checked for out-of-round (but this probably isn't the problem).
Knew a guy that forgot to mark the caps on a V-8 one time. Heh, heh, heh... Took him hours to figure out which cap went on which rod, one at a time.
This is exactly the problem I had. The rods have a stamped number or letter (can't remember which) on the outside of one side. Also make sure your pistons are in correctly. There is a #3 stamped on one side. These are all suppose to be on the same side of the block (again going from memory here, can't remember which side). Also when I assembled the bottom end on my engine, I also put a very thin film of grease on the crank plus the assembly lube. Now that I have this part all back together correctly, everything turns over by hand. It's stiff, but in a good way. If you are having to use too much force to turn it over something is clearly amiss.
Good luck. Come back if you need more clarification on anything.
On mine, I am to the point of re-installing the injector pump and throttle control. I got stuck on two seperate springs. One medium sized and pretty stiff. The other is thiner than a pencil and very delicate looking. I think I have figured it out now so I should be moving forward myself. Looks like I will be installing the engine by late spring in a piece of equipment, so now I kind of have a deadline.
TreeFarmer
GREASE!! that a new one on me in 50+ years of mechanics.All I have ever used is engine oil on the crankshaft bearrings.
Never taken any notice of numbers on caps,I lightly pop or engrave my own on before or as I take things apart .
dave
that a new one on me in 50+ years of mechanics.All I have ever used is engine oil on the crankshaft bearrings.Never taken any notice of numbers on caps,I lightly pop or engrave my own on before or as I take things apart .
dave
Yes, I only used a very small smear. My thinking was the amount was so small it would not make any real differnce long term, but during the assembly process, it couldn't hury. This small amount of grease used would be absorbed into the engine oil once the motor was first started. Mind you I am a newb to engine rebuilds so those reading this follow the vetrans.
Hi Folks!
Thanks for the assistance- we have assembled all rods correctly and double checked.
we may have worked this one out- I sent the crank off for grinding originally - they undersized all journals to the first under size, then they noticed one main which needed further machining, so they under sized all the mains to the next under size. I took it that they under sized ALL JOURNALS to the minimum size! I then fitted bearings accordingly. Now I have fitted a set of first under sized bearings to the #1 rod and it turns over fine.....
I don't understand why when I plasti-gauged the conrod journals they all were inspec. ???? this is strange, possibly the conrod had some sort of distortion when under tension?
Just goes to show you that you should check others work before assembling your engine!
thanks for the help guys
share the knowledge and we all benefit!
Thanks for the assistance- we have assembled all rods correctly and double checked.
we may have worked this one out- I sent the crank off for grinding originally - they undersized all journals to the first under size, then they noticed one main which needed further machining, so they under sized all the mains to the next under size. I took it that they under sized ALL JOURNALS to the minimum size! I then fitted bearings accordingly. Now I have fitted a set of first under sized bearings to the #1 rod and it turns over fine.....
I don't understand why when I plasti-gauged the conrod journals they all were inspec. ???? this is strange, possibly the conrod had some sort of distortion when under tension?
Just goes to show you that you should check others work before assembling your engine!
thanks for the help guys
share the knowledge and we all benefit!
Kubota Newbie
Active member
Equipment
M4500, New Idea Cut-Ditioner, JD 14T Baler, IH "Plow Chief" plows, Oliver Rake
You shouldn't have been able to get a plasti-gauge reading with one size too small bearings! As a matter of fact, the rod caps shouldn't have even fit down on the journal with the shells in them, and once torqued they should've been hard to get off (unless the clearance spec for this set-up is really big). There would definitely have been some distortion, but the plasti-gauge should have been mashed to nothing. Do you know someone who has a micrometer and a set of snap gauges (and knows how to use them) to check things out for you before it's buttoned up? Not trying to scare you, but something is amiss, especially if you got 3 correct plasti-gauge readings.
Not familiar with this engine... But, most rods are supposed to be assembled in the piston in a certain direction AND the rods then go on the crank in a certain direction. This is because the piston pins are usually offset in the piston (not enough you can see it), and because the bearing tabs need to be pointed the right direction. Make sure things are the right way 'round or the pistons might slap like all get out.
Not familiar with this engine... But, most rods are supposed to be assembled in the piston in a certain direction AND the rods then go on the crank in a certain direction. This is because the piston pins are usually offset in the piston (not enough you can see it), and because the bearing tabs need to be pointed the right direction. Make sure things are the right way 'round or the pistons might slap like all get out.
Hi Thanks,
pistons and rods are in the right way round...... I will measure up on the crank-conrod journal again and just check the sizing of these journals. I did find it unusual. I am going to plastiguage the larger brering shells to see if they are in tolerance. If they are too great I will have to tear out the pistons and check the con rod for out of round.
Steve
pistons and rods are in the right way round...... I will measure up on the crank-conrod journal again and just check the sizing of these journals. I did find it unusual. I am going to plastiguage the larger brering shells to see if they are in tolerance. If they are too great I will have to tear out the pistons and check the con rod for out of round.
Steve
Good news on this rebuild. The engine has gone together successfully with correct tolerances on the con rods. No issues with the rest of the process. Ready to fire it up this week end.
thanks for the help
Steve
thanks for the help
Steve
I need a little more help. I finally spent the time to finish putting things back together. Everything went together more or less as expected. In the end I didn't even have any extra bolts left over. Always a good sign in my book.
The one part I did get stuck on was the injector pump & throttle assembly. There are a total of three springs in this general area and I am stuck on where one of them attaches. First is external spring and completely obvious as to the attachment points. The second is internal spring and about the same size. It too, was well diagramed and I had little doubt about where it goes. The third one is where my question is. It is a much smaller spring. A little smaller than the diameter of a pencil and about 2” long. It’s pretty thin/lightweight spring as well. I screwed up and did not take a picture of where this spring went when I was disassembling. I made an educated guess as to where it attaches, but I feel I may have made a mistake. Before I try and start this I do not want to cause myself more headaches. I have attached some picture of where I ended up attaching the spring. Can someone provide some guidance?
Thanks in advance
Always a good sign in my book.The one part I did get stuck on was the injector pump & throttle assembly. There are a total of three springs in this general area and I am stuck on where one of them attaches. First is external spring and completely obvious as to the attachment points. The second is internal spring and about the same size. It too, was well diagramed and I had little doubt about where it goes. The third one is where my question is. It is a much smaller spring. A little smaller than the diameter of a pencil and about 2” long. It’s pretty thin/lightweight spring as well. I screwed up and did not take a picture of where this spring went when I was disassembling. I made an educated guess as to where it attaches, but I feel I may have made a mistake. Before I try and start this I do not want to cause myself more headaches. I have attached some picture of where I ended up attaching the spring. Can someone provide some guidance?
Thanks in advance
As for the first image- This looks correct- same as the one I assembled..... This is one of the governor springs.
I done know what the second image is exactly so I cant help with that.
Steve
I done know what the second image is exactly so I cant help with that.
Steve
Hi
im having some problems with my kubota d722. I was hoping i could get some part numbers for the springs that you were talking about in your pictures. for the injector pump. im having problems with starting my motor and its running very high rpms and wont shut off. i pulled the pump and i dont think it had the springs in it....... smokes a ton as well.
Thanks
im having some problems with my kubota d722. I was hoping i could get some part numbers for the springs that you were talking about in your pictures. for the injector pump. im having problems with starting my motor and its running very high rpms and wont shut off. i pulled the pump and i dont think it had the springs in it....... smokes a ton as well.
Thanks
Hello,
I do not have the part numbers for you, but a good pars shop should be able to help you out. Top picture is the 'start spring'. The one that attaches to the bottom of the speed control devise is the 'govenor spring'. This may very well take care of your idling problem.
The smoking is another issue and well outside of my pay grade!
fyi. My rebuild has been completed for a while but have yet to hook up to a battery and fuel supply and test. I have had a new project that took over but almost finished and back to this one.
Good luck
I do not have the part numbers for you, but a good pars shop should be able to help you out. Top picture is the 'start spring'. The one that attaches to the bottom of the speed control devise is the 'govenor spring'. This may very well take care of your idling problem.
The smoking is another issue and well outside of my pay grade!
fyi. My rebuild has been completed for a while but have yet to hook up to a battery and fuel supply and test. I have had a new project that took over but almost finished and back to this one.
Good luck
Last edited:
Just a quick update on this. I did finally complete this rebuild and the engine seems to run fine. Does need the glow plugs to fire, which does not bother me at all. now for the bad. There is a small oil leak out of the front crank seal. I do think this might be related to me putting the fan pulley on incorrect. It will be a week or so before I have a chance to get in there to take a look. All this is working out just in time to install in my equipment for fall Christmas tree harvest. Thanks to all for the help.
P.S. I am looking for a second D722 motor for the second machine I own. If you have a good used one or a rebuilder let me know.
Thanks Again
Tom
P.S. I am looking for a second D722 motor for the second machine I own. If you have a good used one or a rebuilder let me know.
Thanks Again
Tom
coachgeo
Well-known member
Equipment
L225 w/woods Few Mowers & Back Blade, D722 in Motorcycle (Triumph Tiger), LMTV
There are several of these online. Search by d722e. Some that come to mind are Carrier and SeaBox? or something like that. Also you can search for Tractor D722 and see which kubota tractor has this engine. You can then search for a WSM for that tractor (Work Shop Manual). There is a link in our Ultimate REAMD ME sticky in this forum on WSM's
Hello. I just bought a d722 kubota and pulled the oil pan off and found out the rod cap was loose and the bearing got mangled. Needs rebuilt. The rings are shot. Any ideas on where I can get a good rebuild kit for it? The crank also has grooves in it from the bearing getting mangled.