Muncie transmission oil education.

[whatscooking]

Had A reason to refill my 1963 transmission oil the other day. Had to refill my roll around pump gear oil device. So I was reading the label 80/90 GL5 telling all about extreme pressure and so on then it said for use in non synchronized transmissions. What I thought. So I call the local transmission repair guy that I have known for 40 years. He said that is what he has used for A long time. I said I called A transmission repair place that specializes in Muncie's and they said yes use GL4 fluid, GL5 has sulfer that attacks the brass synchronizers. He suggested A gear oil called Driven gear oil 04530. Not a real big deal he said he said if you constantly use the vehicle but of you park for the winter the GL5 does attack brass.
My local buddie went off saying somebody always has some bul$hit story and so on, whew I thought but the facts are correct GL5 isn't supposed to be used in synchronized transmissions.

 

[BravoXray]

A lot of gear oil containers will say right on the container that they are suitable for synchromesh transmissions.

 

[whatscooking]

Not if it is A GL5 oil, as I understand.

 

[stevem5215]

Yep, it will attack the brass. Trade off of the new oils in this case.

 

[mwayne]

A coworker had to repair the manual transmission in his 92 Chevrolet truck because of using a GL5 gear oil.

 

[number two]

My 1993 Chevy K2500 6.5 with the Nv4500 5 speed recommended 75W90 synthetic to protect the syncros.

 

[rScotty]

Yep, it will attack the brass. Trade off of the new oils in this case.

GL4 & GL5 lube and corrosion differences have been a standard part of mechanical knowledge for a long time. It's standard knowledge for anyone who does manual transmission and/or final drive work. I remember our shop mechanics paid attention to lube type back in the late 1960s.

 

[Williy]

WHAT'SCOOKING Hog jowls and gits sweet patata pie and
possum how said that???

This is the first time I heard someone mention muncie tranny in over 40 years

willy

 

[akguy09]

you could try Delvac 50 or Redline MTL or MT-90

 

[tomplum]

Good post. Definitely that argument will persist as oil discussions always seem to bring comments aplenty. My thought on a GL5 bottle that calls out safe for brass, is information- though not necessarily correct information. Should the info be incorrect, what's the remedy? Your 10.99$ back?

 

[Williy]

The best oil for a Muncie transmission is a GL4 gear oil, which is required for vintage Muncie transmissions. Some recommend Driven GL-4, which is a gear oil that's formulated for classic muscle car manual transmissions. It protects yellow metals and prevents clashing in synchronized manual transmissions.

willy