john deere 4020 no oil to valve train

This message is a reply to an archived post by Tim S on April 16, 2018 at 06:57:30.
The original subject was Re: John Deere 2940 SCV Rebuild.

hello, mr. TIM,, i tried to contact you on your email,, no luck,, so i found this post,, soo,, here goes,, i helped a friend put a head gasket on a 4020,, BUT we are thinking back to an issue we found as we worked.. the rocker arm assembly was REAL dry & worn. the oil for the rockers comes up the right rear corner of the head. i assume from the rear cam bushing, IF that bushing turns that would stop the oil to the rockers,, correct?? if so, can we split the tractor and remove the freeze style plug to get to the bushing?? i know the cam would have to move forward to do this.. your thoughts?? i am little ROBERT, WARRENTON<< VA> [email protected]

Yes that will let you see the bushing,,and there is a strong that is turned to block the oil port. And my old ATT e.mail address is dead,,I can not send or receive it,,and I get little help from ATT,,so my new address is [email protected]

(quoted from post at 10:15:04 02/03/23) This message is a reply to an archived post by Tim S on April 16, 2018 at 06:57:30.
The original subject was Re: John Deere 2940 SCV Rebuild.

hello, mr. TIM,, i tried to contact you on your email,, no luck,, so i found this post,, soo,, here goes,, i helped a friend put a head gasket on a 4020,, BUT we are thinking back to an issue we found as we worked.. the rocker arm assembly was REAL dry &amp; worn. the oil for the rockers comes up the right rear corner of the head. i assume from the rear cam bushing, IF that bushing turns that would stop the oil to the rockers,, correct?? if so, can we split the tractor and remove the freeze style plug to get to the bushing?? i know the cam would have to move forward to do this.. your thoughts?? i am little ROBERT, WARRENTON&lt;&lt; VA&gt; [email protected]

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You have probably discussed this at length with Tim on the phone, I will add this. I am not a JD engine guru but know a little about them. What you are proposing is correct about the cam bearing and if it turns it will block the oil to the top. In my opinion if it turned the cam journal is likely scored to the point that the cam needs replaced. Also the bore the cam bearing drives in may have been damaged. Most cam bearing installation tools have a long shaft that help center the new bushing and keep it straight while it is driven into place. You will not be able to utilize this with the cam in the way. Even if everything was good and you did get the bushing in there with a makeshift driver I would want some assurance that there is a reasonable fit on it before reassembling everything. In my experience that would be sliding the cam back in and turning by hand to at least make sure it is not binding, this would require the cam gear to be removed. Is am not sure if they press fit on those or not. Also once you slide the cam forward and the lifters drop off the lobes I am not sure how successful you will be at getting them to raise back up to let the cam slide back in. You will at least be pulling the oil pan to access them. Then you will need an octopus to help you hold up the lifters to slide the cam back. Your other option is to remove the head to pull the lifters out. I am going to say your project has a somewhere below 50 percent chance of being completed successfully.

Wasn't there a discussion awhile back that said the oil passage hole in the headgasket could be the culprit??

thanks for replying,,