Final Drive normal operating temperature?

[RTJohn]

I just did the 48k mile service on my baby including the final drive oil. Overall it was pretty easy. The oil that came out had a nice pink (Castrol?) color. Anyway, being rather anal about such stuff, what's the normal operating temperature of the final drive? Any bearing will generate some heat when in use. When I get home I put my hand on the hub and I'm able to keep it on. Tells me it's about 135 degrees. Is that OK?

[dirtrider]

Afternoon John

 

If the gear oil was pink that probably wasn't Castrol but more than likely BMW branded Spectro.

 

There really is no NORMAL operating temperature as that depends on ambient temps & the speed/loading you ride it at & to some extent how much braking you do.

 

My 1200RT usually runs about 130°-175° but if I ride fully loaded at sustained 100+ mph it will get well over 200°+ in hot weather.

 

It's not so much the bearings generating the heat as it is gear set tooth friction. Gear tooth friction is pretty high in a hypoid gear set under load.

 

[RTJohn]

Thanks for the quick reply DR. I figured you'd know. Interesting there's such a range of temperatures.