4020 Tune Up

[CaseTech]

Hey everybody, I'm new here, but very familiar with tractors & implements. I am currently in college taking a course specializing in farm equipment & Diesel. As a project I will be working on my dad's 66 JD 4020. It has 250-300 hours on an overhaul, pistons, sleeves, bearings and etc.. But something has gone wrong. It started out missing on 1 cylinder, but would smooth out if it was pulling hard, more noticeably with say a chisel plow or snowblower. It has a set of rebuilt injectors with about 20 or 30 hours on them at the most, this tractor is a yard tractor now, doesn't see any field time. We also tried to find the miss by cracking injector lines but that still didn't work, we are pretty sure it is number 6 but just cant say yet. Then this past winter I was blowing snow as usual and it began to knock horribly so I parked it and it sat until spring. I pulled the valve cover and pulled one push rod out... (it was cyl 3 exhaust valve) It was bent at about a 10 or 15 degree angle about 4 inches down from the top would be my guess, and then found that exhaust valve to be stuck, it was running fine when i started it and it just got bad all of a sudden. Replaced the bent push rod with a good used one and re started and it still knocks.. I will be pulling the head for sure and check valves and get them ground/reseated at least, maybe replace a few. Also this tractor had a M&W turbo kit on it, with a re tuned injector pump until the turbo started spitting oil through exhaust. It didn't blow the turbo but we removed and replaced stock intake and exhaust for the time being. I would like to rebuild the turbo if possible, I dont want to buy a new or used one, i don't think it would be worth my time. Also would like to convert to a 12 volt charging/starting system. I don't much like the 24 volt and I think the generator is shot anyway.

So, if anyone here has any questions, comments, or concerns about my plans, or additional ideas, I would love to hear them. I love constructive criticism (as long as your not too mean about it lol)

 

[mercury65]

you are on the right track with pulling the head im wondering what caused the valve to stick and bend the push rod, rebuilding turbos requires some carful measuring , Ive been a heavy duty mechanic for 26 years and i would recomend you have it done by the pros, also you engine fuel rate has most likly been increased to match the extra air supplied by the turbo, youll know right away if it smokes all the time running without the turbo

 

[CaseTech]

(quoted from post at 13:07:56 09/20/10) you are on the right track with pulling the head im wondering what caused the valve to stick and bend the push rod, rebuilding turbos requires some carful measuring , Ive been a heavy duty mechanic for 26 years and i would recomend you have it done by the pros, also you engine fuel rate has most likly been increased to match the extra air supplied by the turbo, youll know right away if it smokes all the time running without the turbo

It has been without the turbo for a few years, it doesn't smoke much except the usual black smoke when it starts to pull down. I should have clarified I would not be rebuilding the turbo personally, I would send it somewhere. I don't know the model number on the turbo, I will check on that next time I am home. I dont know if that changes weather or not it can be rebuilt or how it can.. most places I think would try to sell me a new or reman in exchange for mine as a core.. I have seen a few different places in threads around here. What are some good places in the Northern Iowa/Southern Minnesota area? I would also consider South Dakota or Wisconsin.. just trying to keep shipping/delivery charges down.

 

[elevatorman 724]

get 12 volt alternator from auto parts store. may have to drill out stock pulley to fit . get 12 volt digram and rewire acordingly

 

[LarrySTN]

A 1966 4020 should have the thin pencil injectors. Our repair shop has tried "rebuilt" pencil injectors several times and have ALWAYS had to junk them and install new. They really aren"t rebuildable, sometimes with specialty cleaners they may work fine for awhile. AT this point we will never use rebuilts. Have your rebuilt injectors tested.

 

[CaseTech]

(quoted from post at 17:34:33 09/20/10) A 1966 4020 should have the thin pencil injectors. Our repair shop has tried "rebuilt" pencil injectors several times and have ALWAYS had to junk them and install new. They really aren"t rebuildable, sometimes with specialty cleaners they may work fine for awhile. AT this point we will never use rebuilts. Have your rebuilt injectors tested.

Yes its the pencil injectors, I never trusted the rebuilt ones either but our neighbor paid for them as a favor, and I cant imagine that they would be worse than the old ones that were in there. We have testing equipment here for injector pumps and injectors so they will all be tested when the time comes. I will probably have to get new injectors, but its a price to pay for a smooth running engine.

And I have several 12v alternators to make fit, I will have to do some digging on the 12v wiring. My only other concern is the starter. If I remember right it has to be switched too? or at least the solenoid I would think??

 

[2520-4010]

could it be that you've lost a valve seat? Just a thought.