Does synthetic resist the shear effect chopping the long chain polymers into little pieces? I thought gear oils were formulated to resist the shear effect of gears and to resist foaming.

However, the Spicer/Brown-Lipe brownie I have says on the info plate to use SAE 50 engine oil, so I use 20/50. It's a crash box.

1951 3800 1-ton
"Earning its keep from the get-go"
In the DITY Gallery
1962 261 (w/cam, Fenton headers, 2 carbs, MSD ign.), SM420 & Brown-Lipe 6231A 3spd aux. trans, stock axles & brakes. Owned since 1971.