Who has done a rear diff gear oil change? What about the front diff?

[GolfRRRR1]

Every spring I go over vehicle maintenance and check to see what needs to be done based on mileage, etc. Because my Haldex oil change was a bit surprising, I plan on changing the fluid every 20k miles instead of every 40k. So I wonder, what about the rear diff? It's not listed on the "vehicle maintenance schedule", there is a drain and fill hole on the diff. So why no maintenance schedule? Has anyone changed it yet? I haven't heard of anyone checking or changing the fluid.
While we're talking about fluids, what about the front? Does the front differential use the DSG fluid for lubrication or is it similar to the back and use a gear oil...haven't heard anything about the front diff either.

 

[hans611]

The front diff is inside the transmission, it uses the same fluid as the transmission....
You could do the transfer case though ("Bevel box") , that's a separate unit from the rest of the front transmission...

It uses the gear oil (G052145S2, 0.9-1L)

I did mine with the transmission flush after I did the first Haldex flush... I am doing the rear diff with the next Haldex flush....

probably wont flush the transmission / transfer case again until I need a new clutch....

 

[scrllock]

Both rear diff and front bevel box (transfer case) use gear oil, different than haldex or transmission fluids.

Guessing the gearbox fluids are "lifetime fluids" i.e. 100k service that you should probably just do every 50k.