GL4 vs GL5 gear oil

[Tic's60]

Just for fun so no stabbings!:nono1:

Myth or Fact GL5 ruins Muncie syncros.


I already did the research but these kind of threads bring out the best conversations :D

[dq409]

GL5 is a different spec, and is not 'backwards compatible' with GL4.

GL5 gear oil is a lubricant with very high extreme pressure performance needed for Hypoid gears where sliding and rolling contacts operate under very high loadings. This is achieved by incorporating high concentration of sulfurized additives. The downside to such high sulfur in oil is it tends to corrode yellow metals, so can ruin parts like brass synchronizers and some bushings. So any equipment needing GL5 performance is designed taking this limitation of the lubricant into account.

GL4 oils are much more friendly to yellow metals, and so are used in equipment where such high load sliding-rolling contacts aren't present. The designers of such equipment aren't as limited in the use of brass parts. So the bottom line is that if your equipment calls for GL4 it probably doesn't need GL5 performance, and you may be asking for trouble down the line if you use a lube it wasn't designed for.

[dq409]

:D Thought I gots some new smarts,, didn't cha !!!

But you did open a can of worms,,,
Thay say the new formula is good if it has the new MT-1 rating,,, read more,,

http://www.eng-tips.com/viewthread.cfm?qid=120197&page=1

http://www.type2.com/library/drivetra/gl4oil.htm

http://www.benzworld.org/forums/unimog/1358944-gl4-vs-gl5-gear-oil-plot.html


HO BOY !!! This is some good reading !!!

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=729289

[rstreet]

DQ I'm getting a different image of you lately..... I'm not sure what it means though!
robert

[Tic's60]

crack! and I was hoping to have fun with this:D The New formula has been out for almost 10+ years though :D Seems the GL-5 today is the GL4 of yesteryear. The chlorine is what messed with the syncos BUT it had to get up to 250 degree's or sit for long periods of time to damage the yellow metal and was removed from the formula.
Thought it was interesting after digging around on info on my Muncie and the oil I needed.