'06 with 49K. What is difference between transfer case and rear differential? Should both get fluid changes? Can this be done without changing auto trans fluid?

 

-Transfer case is basically a small box with a pinion and ring that transfer power from the front differential to the Prop Shaft into the Rear Differential.
This case is separated from the transmission and shares no fluids on your 06 so it gets its own Transfer Fluid NOT ATF! (Basically it uses Regular Differential Fluid, OEM weight is 80W-90) you can use the Excellent Mobil 1 LS 75W-90 in it, You only need 1q.

-The Rear Differential sends power to the rear wheels from that comes from the Prop Shaft from the Transfer Case.
This uses its OWN OEM Fluid called VTM4 fluid, You should use only VTM4 on your rear differential nothing else.

 

Thank you for your clear and concise answer.

 

Your welcome!
Changing both fluids is quite easy and there are a handful of videos on YouTube showing the process..
Since the system is shared between the Pilot and MDX you can also watch videos of the Pilot and use them as reference for your MDX.

 

I, too, am a big believer in the synthetic Mobil 1 LS 75W-90 in gear cases. I did the change-over in the MDX and been running it in my boat-towing Sierra for many years.

 

I had a little trouble finding 80W-90 hypoid gear oil at first, but Amsoil offers it so that's the route I took for my 4G TL. Just changed it this past weekend.

AMSOIL Synthetic 80W-90 Gear Lube

 

^^ Why you didn't go for the SEVERE GEAR 75W-90 instead? If I was already spending on AMSOIL better get the best of the best.

 

^^^ Just my preference to stick with exactly what the manual calls for.

 

Ohh OK Fair enough.