i pulled an engine out of a timberjack skidder yesterday. machine has 5200 original hours on it, this engine won't hold head gaskets, customer has already had two installed in last 1500 hrs. so I removed head sure enough #6 on cam side gasket failure, all piston cracked and beat up presumably by the 3 turbos that went through it last year. pulled liners checked deck my .0025 feeler would not go under straight edge anywhere so block is good, crank and rod bearings on 2-6 have had small particles go through them sometime but not horrible "polishable". so what else? are there any inherent problems with these motors? counterbore cracks? weak main bearings? bad cams? any other tricks specific to assembling these engines???.......theironoracle
Ironoracle , I have built countless of these engines. Seldom do I run into head gasket issues especially with a flat deck. Piston problems are common. General question I am sure you covered judging from other post I have read of yours but here they go. Are they running antifreeze with DCA additive . Was head torqued properly using torque turn method and were head bolts replaced. Repeated turbo failures could be from lack of lube to turbo. Have seen oil pressure regulator stick intermittently . Also pay attention integrity of air intake. Scaring on bearing might require block to be vated . Also fins of water pump are plastic and could be worn and not flowing sufficiently . As far as rebuild goes Max force makes good kit and I have no problem with them. They come with new wrist pins and jd kit does not. Always replace injectors as they are cheap. Use John Deere grommets on fuel lines as the ones that come in the max force kit will leak almost instantly. If water has been run in it or stop leak make sure no debris is in liner oring grooves in block. Mains seals are unitized and will require a tool. I made my own, inside and out must be pushed it together . As far as counter bore goes as long as liner has slight protrusion from deck I roll with it, did you notice any liners below level before removing? Also scrap any crust on block where liner sits. Hope this helps.
Disassemble the oil pump and check that the drive gear is pressed tightly on the shaft.
My memory isn't what it used to be, but I seem to recall an issue with these years ago that turned out to be a conflict between the length of the head bolts and the depth of thread in the block. Apparently was a very borderline situation and some engines that were a couple thousandths shallow in the block had repeat head gasket failures. Bolts would bottom and come up to torque before they had stretched enough for good clamping. Something to look at, especially if the head has been decked at any time. Try threading a couple head bolts in till they bottom and measure the exposed length, compare it to the head height it you can measure it easily at some point. Might be as easy as new head bolts and a thicker washer? Or I could be having a senior moment. Cheers :my2c
Thanks for the info guys, block and counterbore are good, looks like they operated oil filter on bypass the crank had bad scratches in it, I tried to polish them out of crank today but instantly #1 & #7 mains are already to small sent out to be ground .010 under. Pump house said fuel pump had lots of dirt go through it, full rebuild there. I am theorizing that machine has had hour meter changed or the first owner that list this machine to bankruptcy did no maintenance to it at all....theironoracle
here it is complete the rest of the pics will be in thread in shop talk (all in a days work (or two))............tio
it's been quite a few years since i worked at a deere dealer, the new powertech engines had just hit the market, but we had similar head gasket problems with the 6619 motors in the 862 scrapers. engineering pinpointed the problem to excessive engine RPM, as little as 50rpm over the max high idle spec. the engines were producing too much power, the limitation was the head gasket design. we had one customer that replace 15 yead gaskets in one year, in addition, to 2 head gaskets we installed, we had the head resurfaced, block decked and recounterbored. enginerring also pointed out an issue with the 6466 engines blowing head gaskets out the rear of the block due to a slight head gasket leak at the fire ring, and coolant vaporizing in the liner counterbore, and causing damage to the fire ring, eventually blowing out the gasket. :drinkup
Crewchief888, what did you use on the 3/8" plates that meet the main blocks on either end? The book says loctite 515 I used aviation form-gasket (temp range -30f to 400f) and now I get to remove the engine and disassemble and use the loctite because they are each leaking about a tablespoon a day big mess! Trying to figure wether my material was bad or if I used it in the wrong application, guess it doesn't matter, my mess now,......theironoracle
One pic of my problem
we used OEM gaskets, and JD black gasket sealant. a permatex looking stuff that you brush on from what i remember there may be more than one gasket that sorta "fits", the wrong one leaks... like i said, these were earlier non powertech engines that i rebuilt. :drinkup