Synthetic in gearbox?

:?: Has anyone used synthetic (75-90) in the gearbox? I'm about to change the oil in the gearbox. Many of us use synthetic in the gearbox and rear drive on BMW's with good results, smoother shifitng.

Stuart Ostroff

I use Bel-Ray Gear Saver 90wt. Indeed it makes for smoother shifts. Red Line also makes a fine transmission oil. norbsa

synthetic gear oil

Hi Stuart,

I've had Mobil 1 75/90 synthetic in my gearbox all year. Have not noticed any difference in shifting from the 90wt hypoid. but then it always shifted well.