2020 gas. Inframe rebuild or out?

Jdtractor121

New User
Have a 2020 gas engine. Started a
"knock" near the head, definitely not
a bottom end knock. Found 2 strikes on
number one piston but my tractor
mechanic does not believe it was a
valve strike. Valves show no signs of
hitting anything. I found a piece of
metal in number one lifter, and a
piece of metal in the oil pan, so
pulled the pistons wrist pins are
tight as new, rod bearings are in
great shape the main bearings have not
spun. There is nothing visible with
the tractor engine torn down in frame
that explains the knock or where the 2
smaller pieces of metal came from.
Tractor mechanic wants to just take
the motor out and go threw it from top
to bottom, deck the block etc. Cost
4,000 to 4,500. I can rebuild the
engine myself but do not have the set
up to,break the machine apart. So
what's every one's opinion in frame?
Or out? Only thing I've found pretty
worn in,this engine is the liners. I
do believe the bearings are orginal
but I can't say for certain anyone
know how to,tell if they are standard?
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Dunno WHY you are looking in the "lifters" and oilpan for whatever the poor engine inhaled?

Mite as well try to figure out what's going on in the air filter, carburetor and intake manifold area.

Or was something left in that area, or was it sabotaged?

Is this a heavily-used tractor that gets heavy use?

Were there any issues prior to it inhaling debris and starting to knock?

Did it use a significant amount of oil, smoke or foul sparkplugs?
 
Of course pulling the engine and doing a complete overhaul is best but in frame is fine as long as the crank is good.

Bearings are Federal Mogul so any good parts guy(Napa,etc) can look up the number. If they weren't standard they would be marked just under the part number. All yours has is the date.

Looks to me like the engine ate the carburetor butterfly. The melted tips on top of the Piston will be hot spots that cause pre detonation so it will probably knock.
 
It had blow by, i did go threw spark
plugs once a year at least. Its not
heavily used like a daily job, mainly
busy hogging straightening out my
drive way, auger, etc maybe gets ran
once every 3 or 4 months in the winter
once a month in the summer. When I
pulled the oil pan I found a piece of
metal it actually looked like a shaved
timing tooth, but it wasn't as I've
pulled the timing cover to inspect all
gears and they are fine.
 
Thanks for the input. I'll definitely call confirm they are standard. The carburetor is fine that may have been something that happened 20 year ago before I owned the tractor who knows. But it's the only thing I found when I pulled the head. It was a chain effect compression dropped to 60 psi on number 4 cylinder the rest where 120 then knocking, either way I went I was tearing the head off and pulling number 4 piston.
 
My buddy that work on heavy machinery
daily is the one that pulled the
lifters finding that piece of metal
inside of it, looking to see if he
could find what actually happened.
Either way I went head and number 4
piston had to come out as it dropped
compression by 50% at least on that
cylinder. My concern is the metal that
was found, as it's to big of pieces to
just got by the piston rings and into
the oil pan and or lifters.
 
I would do an inframe and have the head done.For your limited use it will last a long time. If you can do the work yourself you should get away well under 2K, about $800 for the kit, $300 for the head plus miscellaneous gaskets, fluids and incidentals. The only reason to pull it is if the clutch is getting iffy or you have a rear main seal leak.
 
I would not waste time or money on O/H'ing a Gas engine, it would be easier and cheaper to swap it out with a Diesel engine..
 
Why would you deck the block??? Don't do that!!!
That bearing is Deere. Probably original with that date.
The part number is for the half and for some reason does
not sub to the part number for pricing (two halves) like
the main bearing still does. New parts system... perhaps
someone else knows how. I can look in an old book.
It's hard to clean an engine inframe. When you pull the
liners that crud runs down on the crank. I have done several
inframe but prefer to pull the engine.
 
If I had the cash I would haha. But I would probably just update tractors before going threw all that. I can't complain I paid 3,400 for the tractor 15 years ago I've done minor repairs over the years and a clutch last year. I wish it was a diesel always have!
 
It may be cheaper to swap it out than to O/H it.... there are a lot of those engines out there...
 
I would absolutely do an in-frame. That based on the assumption that the main and rod crank journals are fine and the balancing shafts are not worn out. No sane reason to pull the engine out otherwise. Nothing wrong with that gas engine either, as compared to the diesel.

By the way, my memory might be off a little. The diesels have balancing shafts that often must be replaced after every 2-3 in-frame rebuilds. I cannot recall for sure if the gas engine has them, but seems it would have to. 4 cylinder engines tend to have a natural in-balance problem that often requires balancing shafts or gears.

When the shafts wear out, the engine oil pressure tends to go to near zero at hot idle.
 
Yes, I know the diesels have the shafts except for a few that were used in 210C backhoes early on. It is the gas versions I am not sure about. Easy to look up, just too lazy to do it. Seems the gas would have the same in-balance issue as the diesel.

Deere sold a few with no shafts and at a certain RPM, the shook so bad the mufflers would break from the vibration.
 
I have a question to those that say "replace it with a diesel." I'd like to know where anyone is finding a low-priced diesel in good shape to fit into a 2020. I cannot say I ever came across one cheap. Note I am talking about proper replacement engines with the heavy blocks made to support the front end of a tractor. Not a modern lightweight made for other uses.
 
It does have 2 balancer shaft I grabbed them there isn't any wiggle in them, there is a hair of back and forth movement but no up and down movement to indicate bearings are worn. Crank and rod bearings are fine none have spun. The cam just eye balling it threw the block looks good but I cannot see the bearings to know if they are worn out. Push rods are completely fine. I have a couple leaky valves in the head but all that could be corrected by reseating the valves. I think I'll just go in frame rebuild. My only problem is getting the front main bearing out. Other ones are simple to push out and push in that front one has a square spacer or something under it that will more than likely have to come out to get the cap off
 
I haven't found any local the used ones I found online where more than overhauling. So i guess it's in frame rebuild see what happens
 
Those shafts are the big issue. If no up and down movement, and the engine had oil pressure at hot idle, sounds like they are fine.

Grinding the seats in the heads is another issue. At least on the diesels - Deere did not use hardened seat inserts. The seats were ground right into the head's cast-iron and then induction hardened. I cannot recall if the gas engine is the same way. Problem is - if you take a grinder to the seats - to any depth - you lose the hardness. With today's unleaded gas - I'd want to make sure I had hard seats when done.

That said - I ground the heck out of the seats on my 1960 1010 Deere gasser. I was just to cheap to have the head machined for seat inserts. So after getting it all done - I had a miserable time for awhile with valve-seat recession. I had to pull the valve cover off several times to loosen up the rocker to get valve clearance back. But that was 20 years ago. After those early valve lash re-adjustments - seems the valve seats work-hardened and have never bothered since.

I suppose part of the oil pump is in the way of your front main bearing?
 
Your cam bearings are probably ok since there aren't any.
As I remember those early engines have to have the front
cover removed to get that block from under the main cap.
 
What about doing the old school method of grinding compound to reseat the valves? I know it isn't the best solutions, but I know a lot of old timers done it that way. I'm glad you told me about the seats as I was not aware of that at all. The repair manuals I have on the tractor calls for a "grind" on the seats but did not mention that the seats are actually the cast head. I'm looking into parts today hopfully get the parts all ordered today. I was under the impression that the last year of the 2020 was 71 so little confused on the 72 bearings. But I've only owned this tractor 15 or 16 years no telling it's history before that. I know a old man couple towns over owned it since new it had a problem I can't remember what so he parked it and a buddy purchased it fixed it and sold it to me.
 
All grinding-compound can do is mark the seats and/or correct minor imperfections. It cannot fix a bad seat or valve face. If you clean your valves and seats with a wire brush, and then lap in with grinding-compound - you will then see clearly what the actual seating areas look like. I suspect most people now adays who rebuild cylinder heads do not use it at all. I do, but only as a marking compound to give me a clear picture of the seats when done. Especially to show me the seat width which usually has to be narrowed after cutting new seats.

As to you heads having hard seat inserts or not? Back when unleaded gas became the rule, the push was on to put hard seats into tractors that did not come with them OEM. Now -near 50 years later? Many were updated long ago. I just pulled the head off of my 1953 Ford Jubilee because it had some stuck valves. I did not know what I was going to find inside. Ends up it has hard valve-seat inserts on the intakes and exhausts. Must of been done way before I owned it.

If you are doing a budget job on your tractor? If you clean the valves and seats, lap and clean, and find no bad spots or leaks? No problem putting it back together. You might want to add some valve-stem seals on the intakes. Back in the 60s and 70s, Deere did not use any positive stem-seals except on the 1010 and 2010 engines. Kind of odd, but that is the way it is (or was).

Diesels are a whole different story. Deere claimed valve-head depth in the cylinder-head is critical. So grinding usually sinks them too deep. So a diesel usually requires seat-inserts put in to get the assembled depth correct. That or over-thick valves like TRW used to make. No such problem on a gas engine though.

If you grind those valve-seats lightly, you might not even cut through the hardened areas. You will know when you do. It goes from hard to soft pretty quick.

If it was mine, I would inspect the exhaust valves closely and make sure they have not already been refaced previously. If the heads are thin, you are better off just buying new exhaust valves. When exhaust valves get refaced too much and the margins get too thin, they overheat and burn up.

Back to the subject of your main and rod bearings. If you measure clearance and find mild wear - keep in mind you can put in slightly undersized bearings - assuming they are still available. Deere used to sell .002" undersize made to install during an in-frame rebuild if there was mild crank wear but the journals were still smooth. I have installed many over the years. Now - are they still available? That, I do not know. Deere DOES still show them in the current catalog.


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I have no issue in sending it out to,the machine shop, just dodnt want any issues out of grinding the seats, as you know the guys who know these things about older tractors etc are getting few and far in between. I had been considering on ordering all new exhaust valves but I guess I need to knock the springs and keepers off to really inspect my valves to determine what kind of shape they are truly in. Thanks for your input and knowledge on the tractor and it's repairs as I'm not a tractor guy, I'm a gasoline vehicle guy so stepping a hair out of my element here.
 

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