Knocking John deere A

[Anonymous-0]

Friend of mine has a 1950 A that is knocking, sounds like on the left cylinder. I have taken the crankcase cover off and checked the rods wrist pin bushings and camshaft gear. Have checked the Flywheel, and bolts, and clutch driver. We removed the cylinder head and checked for something on top of piston, but have come up with nothin. I have worked on quiet a few of these 2 bangers. Have even built two bored and stroked Deeres. One G and one A.
I thought maybe it had a bad spark knock and tried some good gas but did not solve problem. I failed to mention that it only seens to knock at Idle, when you speed it up the knock seems to go away. Just wondering if anyone has ran into this problem before. Any help would be appreicated.
THANKS.

 

[jturbo10]

Have you checked the torque numbers on the flywheel bolts and checked out the end play? How long since it has been overhauled. Sounds like piston slap or worn wrist pins. I'd suggest using a mechanics stethoscope and target areas on the flywheel side to see if you can isolate an area although sound can migrate from other sources. Does the knock go away at idle if you engage the clutch with the gears in neutral? Good luck on the noise...most of my experience with that kind of noise has been piston or flywheel related.

 

[Anonymous-0]

We have checked the Flywheel bolts, it is knocking at idle with transmission in neutral and clutch engaged. I will agree it could be a piston slap or wrist pin bushing. I did check the wrist pin bushing by reaching into crankcase and shaking the rods, but did not get any movement that way. Like I said it only seems to knock at idle. When you raise it off of idle it seems to go away. Thanks for the information.
I may have to pull the pistons out and check a little further.

 

[RLA]

I wonder if it"s been over hauled & had a pair
of alumium Pistons installed. They sometimes
will make some noise with no load.....

 

[lyric]

Does It seem to have good oil pressure? I have an early 47 AN that had a knock sounding simalar to what you decribe, found it was a broken oil pump coupler. Joys of buying new toys that don't run when you get them! Good luck with it. Kevin

 

[Anonymous-0]

check the little flywheel inside the pulley they sometimes come loose

 

[[email protected]]

HOGWASH! If they're fitted properly they DONT.

 

[alvan]

I have a 45 doing the same thing. Bored out to 125 over with aluminum piston"s making a nock on the flywheel side. We have tore it down three times and still cant find anything wrong. We have used 112 octane gas still does it .after running few minute it goes away. STUMPED...

 

[rick deere]

You have to take rod lose and take rod cap off then ck to see if you have move ment back and forth in the piston bushing can not do it anyother way.

 

[pjmo]

check your idel rpms is she running too slow and the oil pressure is too low? above M on guage? oil thin? gas in oil ? increase the oil pressure till it stops knocking... use a heaver weight oil? straight 30w adjust the low idle screw till it stops knocking 450rpm +... watched Robert's carb video his carb adjusting tractor motor/dino the A ran at 333 rpm producing 30 hp on dino with a 720 carberator that he rebuilt too pre adjust before shipping. it wasn't knocking. I think low idle the 60's operators manual is 600rpm if i'm remembering correctly. is it getting hot? smell of hot oil? goodluck pj

 

[Mike M]

I can say I have seen alot of A cam bearings bad. Can't say I heard them though.
I had a late 40's era A that at some point had insert rods added. One of them was slightly tapping on the top of the crankcase. Took a long time to figure it out. Short time with a grinder to fix.

 

[bmiller36]

push the clutch in when its running at med idle if it quits knocking your flywheel is loose .Bob

 

[BushogPapa]

My Late Styled JD "B" has had a thump in it since it was bored 3/16" in 1960.

Sounds like a wrist pin or some play in a Main bearing, but it measures OK..

I pulled it down and didn't find anything and it has not gotten one bit worse in 53 years..

A slow idle will not hurt these at all..as long as there is oil pressure..

Ron..

I don't even pay any attention to it any more..it is just the Nature of the Beast..Large parts have a habit of making a little noise..

Ron..

 

[teddy52food]

If the head is still off, I would take out the pistons and mike them. If not, do you see any signs of scoring on the skirt when at BDC? Sounds like too much clearance & when it warms up the piston expands enough to quiet down again.

 

[deerenutz52]

I agree, use the stethescope to try to isolate where the knock is ocming from. Just a thought, but the cam gear drives the govenor gear on the left side, could maybe me something in the govenor?

 

[JDG]

Check for worn clutch drive splins or bolt in end of crank not tight allowing clutch drive to be lose on crank

 

[elkcagg]

Yes, with engine off, remove pulley cover, engage clutch & try to rock the pulley back & forth. If it moves even a hair & the crankshaft doesn't you'll get problems here as well. Let us know what you discover.

 

[RLA]

It isn"t hogwash if they aren"t fitted
correctly? I completely agree with you.
A machine this old could have many once upon
a time repairs... He"s searching for a Noise/
knock.. Loose alumium pistons knock will change
under load or higher RMP,s. So far everything
he"s checked seem OK....

 

[40Utility]

Have you checked the bearings for the first reduction gear?

 

[TC5542]

SOMETIME OVER THE YEARS THE FLYWHEEL HAS BEEN RUN LOOSE. EVEN THOUGH NOW TIGHT IT HAS WORN . LOOK FOR INPLAY IN AND OUT ON THE CRANKSHAFT. CATCH HOLD OF FLYWHEEL, AND TRY TO MOVE IN AND OUT. IF CAN MOVE ANY, IT MOVES IN AND OUT WHEN RUNNING CAUSING AN EXCESSIVE MOTOR KNOCK. MAY CAN TAKE SHIMS AND SHIM JUST A SMALL AMOUNT AND STOP KNOCK