I used their 75-140 in my differential. I changed to Lube Engineers because it was a straight 90 w. No problens with either but I think the LE runs a bit batter.
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93 D-250-114,000 mi. , 3" Straight exhoust, BD converter & Injectors, 16 cm Turbo, PacBrake, factory electric cooler, 18gal aux fuel tank, Mag-Hytec diff. cover, rear sway bar, gages, 33ftAutomate 5th wheel.