Im not sure how many of you guys have experience with the deere 466 motors but i have a question for yous that do. We keep dropping valve seats out of the heads on our 4440 (twice now) and our 4430 now also. For a little background: We use thse on a daily basis with the fuel pumps set stock for farming. They were never overheated (Weve rebuilt both these so i know) We have the heads done at a local machine shop. We do trun the fuel to them when we pull (on average 6 times year) but then they go right back to stock. O yea one more thing? the 4440 dropped the valves both times while stirring manure. We wonder if the methane fume off of that could be the culprit?:confuzeld Is anyone having similar problems with these heads and if so did you find a solution. Any help is appreciated, I hate having to rebuild a good motor for a dropped valve.:mad:

Interesting idea about the methane. I could see that. I probably won't see anyone before the weekend but I will try to ask then.

Keep the ideas coming guys...i could really use some help on this one

What series of head are they? The 55 series head is notorious for having bad valve seats when you pull with them.

I dont know how many hrs. are on them, but thay are getting old 30 to 35,years old. i bet you that the heads are cracked from the injector hole through the valve seat bore, thus making the seats not fit properly and letting them drop out. the cracks come with age. i would find a better machine shop that knows what thay are doing and get them fixed wright and you should not have a problem.

What series of head are they? The 55 series head is notorious for having bad valve seats when you pull with them.


I was hoping no one would say this.......looks like the old motto "pay to play" is coming back to bite me in the a**:(

By the way what series head are you runnin in your puller?

Just a question, can you buy oversize seats for that head? I have seen 3406 Cats drop seats and we always sent the head in as a core, as once a seat is loose, you have to spray weld all of them and replace all the seats. We tried repairing one once and it cost the guy a kit, and a head, as another seat dropped within a year, and jammed and destroyed the piston. Luckily he was idling and it just stopped.

ill be honest i dont know a whole lot about these heads...when we do a motor the head comes off and goes down the road and we dont touch it as far as cleaning and the valves, etc so im not sure what all goes on or even what u can get:o:

We run a 55 series head but it has a bunch of work done port, polish, milled, ect. We do have oversize valve seats, so yes you can get them. Haven't had a problem yet and we have ran it for over two seasons now. Also my guess is that the methane probably didnt have a whole lot to do with the valve droping but the tractor operating with a load on it several hours while stirring manure just a guess:confuzeld Also how many hours did it have on it when the valve droped? Was it the same valve that droped both times?

I would think you would have dropped from the methane as well than. I don't think you had high enough concentrations to hurt the engine or yourself. It is old and needs repaired properly.