Well first off John Deere does not issue "recalls". There may be a "PIP" available for certain engines in certain products to help with a certain problem they have discovered may happen. Right now for the 9.0L in 70's combines we are ajusting the cylinder liner standout in some of the engines because it was set too low at engine works and there have been some head gasket failures. Thats the only one we are working on now and the only one that I know of issued in our area. What is this NAT by the way?
jdtech1998 has there been a issue with the machine of the counter bore in the block and it is cut to deep? How much to low are the linners? Do you have to cut the counter bore and shim the linner hights?
If I remember correctly, about 10 years ago I heard of a similar problem that had plagued either the "8630 or 40" 4WD tractors in our area from years and years before. It seems odd that with the latest JD technology and quality control we are still hearing about these types of failures?
Read my post again. It was 10 year ago that I heard of the same problem in the "30 or 50 series tractors that had occurred "YEARS AND YEARS BEFORE". Our local JD dealer said they had several early 4WD tractors with counterbore problems therefore what's changed?
I didn't make up the story and about 10 years ago I did buy a 9400 so I know the chronology of John Deere models too.
Can you imaging how sharp that cutting tool is that cuts the bore for the liner to fit. I can see how it easily could make one more thousandths or two too much cut. Especially with all the engines Deere produces, a tiny fraction too much cut on a handful of production is real possible.
But, on the other hand, if my near new $250,000 combine started leaking antifreeze in the oil, and unknowingly I had operated with it doing that for up teen hours, or all season, until the PIP was announced, and all Deere recommended was liner shims, disregarding the damage the antifreeze did in the crankcase, I'd be pizzed-off too.
Maybe negotiate for a new crate short block motor with Deere rather than perform the PIP? Yeah extra dough spent to correct a problem caused by Deere, but also get all new motor, bearings, crank, liners, rings, etc a short block provides. Basically starting this season with a new motor that way, and not a dealer installed PIP. That is what I would do. It doesn't take much anti-freeze in the oil to wreck the bearings.
The tool must be along the lines of a "CNC" type machine, no doubt computer controlled so it should be able to accurately reproduce those cuts day in and day out, or maybe they "out source". I noticed my replacement thermostat for my "4020" was made in Mexico.
From what I have gathered from the PIP and some engine schools, I am not sure that it entirely a problem with the counterboring process. The new 9.0L engines run at a much higher compression ratio than the 8.1's did and the spec given to engine works for liner standout was kept the same as the 8.1, .003 to .005" If the the counterbore happens to be around the .003 or gets machined to .oo2 by chance, the higher combution pressures are somtimes cause gasket firing ring failures. Deere has issued a new spec of .004 to .007" of liner standout and some of the engines are being issued PIP's to have there liners shimmed a minimum of .002 reguardless or more if needed to get within spec. And YES not all engines are affected just a string of them that were possibly overmachined by .001 to .002". I saw one failure only in the last 2 years and only heard of one other in our area at one of our other stores. I was nothing drastic and did not even keep the customer from using the machine. I just started running really cool all the time and was venting exhaust and compression out the overflow. Out of 200 or so 9.0L engines in equipment we have sold the last couple years only 5 have been found to need PIP's.
................................................................................................................. go to tractorata.com some of the new deeres are mae in mexico for example the 6D series are