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|Allis-Chalmers One-Ninety XT|
|Weight||7,675–11,300 lb (3,481–5,126 kg)|
The Allis-Chalmers 190XT, also known as the One-Ninety XT, is a diesel*-powered tractor that was produced by Allis-Chalmers. As its model number implies, it was based on the Allis-Chalmers D19, though it featured many alterations and improvements over the D19. The only difference between the 190 and the 190XT is the addition of a turbocharger on the XT. The 190 XT in stock form is rated at about 93 drawbar horsepower. They were produced from 1964 to 1971. The 190XT was notable for being able to outperform the 103 horsepower rated Allis-Chalmers D21 (until the D21 was turbocharged in 1965).
- *A small number of gas and LP gas models were made, but these were not the XT because the XT meant that it was turbo-charged
The 190 XT had a six cylinder engine and a 3.875x4.25 inch bore/stroke. Its displacement was 301 cubic inches and its rated RPMs was 2200. This engine was a new design and, for the time, offered excellent performance for its displacement. Its main transmission, basically a carryover from the D19, had 4 forward and 1 reverse gear and was not synchronized. The 190 XT had a power director like the D Series, but it could smoothly shift on the go (clutch engaged)just like the D series. The main transmission could not be shifted while the PTO was engaged and turning and as such the 190 did not offer true live PTO. You could start and stop the tractor using the power director but you could not, for example, shuttle from forward to reverse without first stopping the PTO. The power director did split each gear allowing for a total of 8 forward speeds and 2 reverse speeds.
The 190XT, because it used many D19-size components in its powertrain, was intended to be at most a 100 horsepower tractor. However, many of them had their injection pump turned up, pushing them to 120 horsepower or more. This led to various powertrain failures, especially in earlier models due to a light rear end design. An improved design was introduced and many tractors were updated with the heavier duty rear end. Also, the 190's transmission did not tolerate grinding during gear shifting well and this led to many tractors with transmissions that would not stay in certain gears. As such the tractor got somewhat of a bad reputation among those that weren't AC fans.
The 190XT was gradually beefed up, becoming the 190XT Series III and eventually the model 200. When operated as intended by the manufacturer, the 190 was a reliable tractor. However, this meant accepting its limitations and not, for instance, trying to shift it like a John Deere 4020 with its synchromesh transmission or pulling implements designed for D21-size tractors.
Despite stiff market competition from the John Deere 4020 and others, Allis did sell many 190XT tractors and there are many still working today. Allis-Chalmers and the Gleaner Harvester Corp. was restructured in 1985 and eventually became Allis-Gleaner Co. AGCO Corporation and as such what parts are still available for these tractors are mostly available through AGCO.