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Gear Oil - 75/90 vs. 75/140

Discussion in '80-Series Tech' started by Tengai, Jan 19, 2010.

  1. Tengai


    Likes Received:
    Dec 14, 2009
    Need some advice, on an original geared 178k mile '94 LC, any opinions on running Mobil 1 Syntehtic 75/140 to quiet the pinions down a bit? I have read on re-geared (bigger gears) trucks, it is sometimes works to use 75/140 to quiet them down a bit but, wasn't sure on stocking gearing with the mileage my truck has on it. The LC currently has 75/90 non synthetic in it. Thanks in advance!