Getrag mechanical transmissions...

[vox_incognita]

Hi,
I`ve been browsing the archives for hours...
I know the second generation w123`s come with Getrag 4-sp.transmissions(integral bell housing,the MB trannies have the detachable housing),some 300`s with a 5-speed(rare)...
Are all w124`s equipped with Getrag boxes?When comparing the gearbox designation numbers and sales designation codes mentioned in these sites:
http://www.bekkoame.ne.jp/~mtor/mbtypecode.html
http://www.4x4abc.com/G-Class/transmissions/getriebe.html
...I got the idea that every GL.XXX transmission is a Getrag one. Is this correct? Above all,seem like all 717.XXX gearboxes are GL.XX(Getrag?),except for 717.000 (G 76/27 - 5) which for certain is a MB-made 5-speed manual.
Do I get the picture right?What I come to is only confirmaton of what Chuck Taylor wrote "Then in the 80's Mercedes started using a Getrag 5-speed in the 107, 124, and 201 cars. In the US you see them mostly in the 300E and 190D/E. Linkage again on the side."

Another thing-the local dealer insists on using some "special MB oil" ($$)for GL68/20 C-5(717.41,5-sp.manual),which seems to be nothing more than a MB235.10 API GL-4 SAE 80W oil,widely available on the market. However ,I have NEVER seen anything but ATF fluid recommended for manual MB transmissions from the mid 50-ies to ,say,mid `90-ies.(lubric.chart,online oil guides,printed service MB manuals etc. )
I realize SAE 80 is close to ATF in terms of viscosity etc.-are these two fluids interchangable in 717 trannies?
Really confused... and what`s most annoying-never met a hint of any SAE 80 in the manuals(except for G-klasse transfer box).
Thanks! Any help much appreciated!

[moonshine]

Vox, Your question on transmission fluids can best be answered by David at REDLINE 1-888-624-7958, at least he helped me. Moonshine