Transmission Oil
#23
09-25-2010, 04:24 AM
#25
09-25-2010, 05:46 AM
Seasoned HDF Member
Damn...Son... how much do they pay you to come up with this ****. LOL...freaking brilliant.
#26
09-25-2010, 06:28 AM
#28
09-25-2010, 08:01 AM
Seasoned HDF Member
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so to throw a wrench into the works, mobil1 says not to use gl5 gear oil in a tranny that has 'yellow metal' ie. brass, etc. our tranny fits right in there. not a lot, but some.
mobil1 is gl5, amsoil is gl5, just about every gear oil i've looked at is gl5. so what to do?
mobil1 vtwin 20/50 is not gl5 (since it isn't gear oil...) but is rated for our trannies and is close in viscosity. i think i will use that.
i don't know how quickly (or long) it will take for the gl5 to do any damage, but i'd rather not chance it.
mobil1 is gl5, amsoil is gl5, just about every gear oil i've looked at is gl5. so what to do?
mobil1 vtwin 20/50 is not gl5 (since it isn't gear oil...) but is rated for our trannies and is close in viscosity. i think i will use that.
i don't know how quickly (or long) it will take for the gl5 to do any damage, but i'd rather not chance it.
Don't you think that is exactly what mobil1 wants you to do,
is to use their product?
What did they base their conclusion(s) on their unbiased independent studies?
Please tell us what mobil1 says will be hurt and why we should not use it...
#29
09-25-2010, 09:51 AM
Seasoned HDF Member
their conclusions are based on the fact that in the gl5 oils, there are sulfurs that are acidic to brass and copper. i was doing a lot of reading last night, and from what i can tell, 'modern' gl5 has buffers in it that are supposed to mitigate the yellow metal erosion, but no one is really sure how long those buffers actually last.... a lot of applications that use gear oil have much longer service intervals than our trannies (even at the recommended 20k interval) so the sulfur buffers may still be doing their job, but i guess the only way to really tell is to have an oil analysis done. supposedly gl4 oil has sulfur in it as well, but at a much lower level.
if you're tranny oil is gl5, look on the label and see if it says 'yellow metal safe'. you can also check the msds and look for the copper corrosion numbers, 1a is absolutely no discoloration (ie corrosion) and 1b is slight.
if you want more info on it, go to bobistheoilguy.com and do a search on 'yellow metal'..... i'm still looking for the 'definitive' answer
Last edited by skratch; 09-26-2010 at 02:43 AM.
