450 outside temperature sensor

[tolsen]

Any idea what the relevant standard is?

Most likely ISO 4156.

[Thrumbleux]

Thanks TK. Much appreciated.

[mottofreee]

There is a direct link between oil viscosity and mass.
One theory says that a thin oil has less mass and can lubricate easier upper part but not so great sometimes penetrating power.
If it is thinner, drain quickly, especially in the presence of the shear forces, centrifugal and centripetre but you can guess the rest of forces horde of engineers at Daimler R & D have been considered.
Tribology is a very large, so use fluids recommended by the manufacturer.
In this case (the W450) is recommended Mobil ATF D 21065 (only) http://www.mobil.com/UK-English/Lube...F_D_21065.aspx , oil no longer occurs or is found only jug of 20l .
In conclusion we opted for Motul Dexron IID https://www.motul.com/system/product...pdf?1335541304 oil which has substantially the same characteristics .Mobil ATF220 or Comma AQM are too thin.

[mikerj]

My conclusion is that Getrag design engineers had done bearing life calculations and found too short life for three high loaded bearings. A simple solution was then to specify double sealed grease lubricated bearings for these to ensure a reasonable overall expected life of the transmission.

The answer is pretty obvious if you look at the orientation of the gearbox and the location of the oil filler/level plug. The diff bearings are partially submerged in oil, but the first motion shaft and layshaft sit way above the oil level. The gears themsleves will be adequately lubricated by oil transfer and splash, but the bearings are shielded by the gears so oil lubrication would be minimal.

[tolsen]

It is not that simple. Input shaft bearing nearest to flywheel has no seals and is therefore oil lubricated.

[tolsen]

Both input shaft and lay shaft are wetting the oil. Lay shaft is nearly 100% submerged but has sealed grease lubricated bearings both ends.