I'm not bashing your thread, and you asked why it isn't in use. Stop and think about what that article is suggesting. It's talking about uninterupted power flow from the engine to the wheels through two shafts. This is done 'wet clutches' 'Phasing in' and 'phasing out' each gear. It states that there are complicated electronic and hydraulic controls for this transmission. The 'phasing' of gears on these clutches is fancy speak for saying that the clutches are being slipped in a soft shift, the same as is done in a lazy shifting automatic transmission. It's not that a transmission like that couldn't be fitted to a farm tractor. It's that it's not a practical thing to do, in my opinion for a farm tractor. The reason that the Select-O-Speed (and perhaps some of it's counterparts of that time) didn't work is that it had poor manual controls that resulted in a poor shifting, jerky transmission. It didn't get coined the Jerk-A-Matic for nothing. It earned it. The eliptical gearing of those transmissions was actually pretty reliable. It was the controls that were poor. That's why manual controls don't work well in most cases. The modern power shifts mostly use a complicated mass of speed sensors and modulator valves to control the shifts. Their timing and pressure is that critical that they must be recalibrated in service to compensate for wear over time. It's my belief that it's nearly impossible to get that kind of timing from a manual control system, in a way that is repeatable so as not to destroy the transmission. Think what you like, but planetary transmissions are what's out there today. If this technology had any merit in an ag application, I find it hard to believe that someone would not have done it by now because it could be somewhat more efficient.
We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]
Today's Featured Article - Madison's County - by Anthony West. Philip Madison has been a good friend of mine for quite some time. He has patiently suffered my incessant chit chat on the subject of tractors for longer than I care to remember, and on many occasions he has put himself out, dropped what ever it was he was doing, to come and lend a hand cranking handles, or loading a find onto a trailer. Although he himself has never actually owned or restored a tractor, he was always enthusiastic and always around helping with other peoples projects.
... [Read Article]
Latest Ad:
1965 International Harvester McCormick Farmall cub tractor 2,500. Two owner tractor. My grandfather bought new in 1966, then we inherited it. Have all the paperwork original manual and all maintenance records. It starts and moves. Comes with underbelly mower, plough, and some other attachments.
[More Ads]
All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy
TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.
