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Yep, the 89 is the same. It was the 1st year of the 4.0.
As for rear axle, a D44 is not what you want. The ideal axle (and almost a bolt in) is a 31-spline explorer 8.8, which is stronger than a D44. They were available with gears from 3.08 to 4.10 (depending on year and options). An axle from another ranger (7.5 or 28-spline 8.8) will be a direct bolt in; you just have to find the ratio you want. Rangers also came with 3.08 to 4.10 gears. See the tech library for how to identify which ratio any specific ranger has.
As for rear axle, a D44 is not what you want. The ideal axle (and almost a bolt in) is a 31-spline explorer 8.8, which is stronger than a D44. They were available with gears from 3.08 to 4.10 (depending on year and options). An axle from another ranger (7.5 or 28-spline 8.8) will be a direct bolt in; you just have to find the ratio you want. Rangers also came with 3.08 to 4.10 gears. See the tech library for how to identify which ratio any specific ranger has.
