I am looking for the proper gear lube for a 1934-5 one and a half ton truck 4 speed transmission. It doesn't have synchros. I have been told I have to use GL4 gear lube but it's have proven difficult to find. Can I use GL5 in this trans or are there outer "yellow metals" in it that would be damaged by GL5?
GL4 or GL5
- Thread starter Rance29
- Start date
deuce_roadster
Well-known member
NO synchros = no brass so you can use GL5 in it if you want. The 4 has a weaker additive that doesn't harm brass like the 5 will. For the cars 5 in the rear end 4 in the trans. That is my undedrstanding.
J Franklin
Well-known member
Maybe the reverse idler runs with a yellow metal bushing.
truckdog62563
Well-known member
O’Reilly’s sells MasterPro GL4 SAE 140 in gallons. Cheaper than name brands on Amazon too. Stu