Mustardxf 29 Posted June 28, 2015 Whats the best oil to run in a 4 speed single rail? behind a fairly beefy crossflow. Share this post Link to post Share on other sites
Stevemack 122 Posted June 28, 2015 Good old 80/90 mate. Share this post Link to post Share on other sites
gerg 10,871 Posted June 28, 2015 Factory says engine oil or SAE 30 mono grade. If you want to get fancy it won't hurt to run a synthetic oil like Castrol Syntrans 75w85 or a light gear oil specifically for jap truck boxes. Whatever you do, don't run an EP or EPX type that you'd run in a diff. The syncros don't like it. Share this post Link to post Share on other sites
Fingers 466 Posted June 28, 2015 I have run ATF in them, with no obvious problems. Share this post Link to post Share on other sites
NZXD 2,328 Posted June 28, 2015 I put 75/85 in my freshly rebuilt single rail, that was on the advice of a single rail guru. 1 gerg reacted to this Share this post Link to post Share on other sites
broken-wheel 659 Posted June 30, 2015 I run http://www.penriteoil.com.au/products.php?id_categ=1&id_viscosity=161&id_products=591 Works really well, running gear oil in a single rail is fucking stupid and good way to break the selector fork going into 3rd Share this post Link to post Share on other sites
