Originally Posted by
Duragrouch
I did not know that! Thank you! Wow, important, I'm not sure if any synchronizer rings in some manual gearboxes have bronze in them. My '90s GM manual trans used ATF, I thought to perhaps just standardize, but that may be a reason. A different sporty car I owned spec'ed (IIRC), GL4 but at an enthusiast meeting with a factory rep, they said they were getting a bit of buzzing during shifts (too much slippage at the synchros), so recommended one number down, GL3, a bit less slippery. I currently use gear lube for all my bike lube; chain, derailleur pivots, v-brake pivots, and the latter may contain a bronze bushing; I lube with grease at rebuilds but sometimes put a drop of lube there between rebuilds; I'll have to check on that at next brake overhaul.
remember though, that same poster thinks 10 and 20 weight oils are the same as 75 weight oil... etc.
all modern manual transmissions have syncros in them.. they are bronze... they wear, no matter what a driver does... they are SHIFTING CLUTCH PLATES, and are designed to slip some, easing shock to the hard steel gear teeth....
and the more a syncro slips, the more it will wear before the TEETH on them engage with the gear involved..... less syncro slip is better.
teflon additives for transmissions should be banned, IMO.
And ATF is made to allow clutches to Engage quicker. If it wasn't, the shift bands/drums/plates (Clutches!) would wear out in a big hurry...
There are "Motor oils" made to work with Clutches too... they are specially made for Motorcycles. My fave is Honda GN4
there are multiple examples of bronze bushings bathed in gear oil... i have not seen any of them with "corroded bushings".. EVER... worn out? yep. but not one "corroded"
i've been a pro mechanic for about 40 years now... i've worked on a wide variety of machines and equipment in those 40 years.