The lust for john deere??

Lonn if your expecting JD to be honest you must believe in Santa Claus  .......just kidding

You better check you facts a M2 competed with the 6620 combine it was a 6R machine a 7720 was an 8r machine and competed with the L2 . The facts on your side are the ones that are wrong, I sold Gleaners I know what was competing machines, I know what we sold against and I know what Allis Chlamers used as competitive models at the college of Knowledge. so now what your point???

All those JD you mentioned KcGrain are later than the early 4020. The early 4020 like I have had a check valve AT the transmission pump and works like I described. The later tractors didn't. The check valve does fix the problem in the pre side console 4020. Like I said on my web page. The JD service bulletins I have say at least in the index that loss of hydraulics with the clutch pushed in the later tractors isn't from a bad check valve, because there isn't one but is from a high pressure leak which could be plumbing or any of the valves that have pressure on them all the time. My service bulletin collection is missing those issues that cover the later tractors. In my 4020 the remotes return TO the transmission oil filter that is at the pressure of the output of the transmission pump, not to the sump. And my loader returns there too. A single acting cylinder that has no load will only open, it won't close because it has that 250 psi or so pressure still applied. If the remote return went to the unpressureized sump that wouldn't be a bother. That way the reservoir up front only has to supply oil for single acting cylinders and the difference between the front and rear sides of any double acting cylinder so it can run a while with no transmission pump. Has to be that way because the capacity of the transmission pump is a fraction of the capacity of the front pump.

I said NOTHING about Green Magazine, the article I reference is from Two Cylinder Magazine out of Grundy Center, IA.

When checking shop manuals you have to go to the OLD 4020 manual SM-2039, not the TM for the side console tractor. The only things the hydraulics of the two share is oil, and the front pump, maybe 2250 psi closed center. Everything else, including the remotes is wildly different. The side console remote was used for decades after 1970. The shop manuals for the two vintages of 4020 are completely separate as are the parts catalogs. That's because the two tractors are too different to be covered in the same books. Some parts interchange, some don't. Some that fit don't work right.

AC didn't get to helical gears until the very last of the WD and the WD45. When shifting sliding gears, I suspect helicals shift a lot tougher than straight cut gears and cost several times as much to buy or make. Though the noise of straight cut gears didn't seem to bother Massey-Harris and their model 44 or a late Cockshutt where the whine of the gears, even unloaded is louder than the engine exhaust. The 4020 SR (and PS) don't slide gears about, the SR uses cogged clutches of which some are syncrhonized and some not and the PS uses disk clutches with hydraulics to do the shifting.

I've not memorized the PS portion of the shop manual, don't have one, don't plan on working on one. Nor do I want to work on my 4020 innards.

Gerald J.

Gerald and Jack, Allis was using helical gear transmission by 1947 in the crawlers and by 1950 in the CA.

Edited by Lonn - 04 Jan 2011 at 6:36am

  I want to thank you both for the good reading. You both have made good points, i will not pick sides, but  i was born and raised on AC all the way threw childhood, knew a lot about all there products and loved most. I am 62 years old now and farm 1300 acres with almost total JD equipment.  At age 20 , i went to work at local JD dealer and spent 10 yrs. there , mostly as a mechanic, and know 4020 very well.  I have 2 Jd 4020's as of today, one is a 65 (first yr.) and one is 72 (Last yr.) both is excellent condition, and just to let you know i also have my dad's  orginal WD-45 Diesel completely restored to showroom condition with the orginal purchase agreement from the dealer with the date and price  of sale.  So  i just wanted to Thank You both for the interest in the subjects and to let you know this will proably not be the last word about those 2 companys and there products.        Dave( in Mi.)