initial change of front AND rear AXLE fluids (and transfer/transmissions initial flushes)

[Black02Silverado]

21 minutes ago, Mic_ said:

thanks for the discussions.

 

My older 2001 2500hd

GM recommend rear axle fluid after like first 1000 miles of towing.

 

did not know if the new ones are this way now also.

It's a good idea especially if you have never changed it.  AMSOIL recommends changing out the fluid after 500 miles.  This way it gives the gears time to wear-in and you get all the possible material from the wear-in out. 

[nocturnalmotors]

Is there a GM source that states what type of fluid to use in the front and rear gearcases? My manual states see dealer.

 

Edit: found in the sticky done by newdude.

Edited September 19, 2022 by nocturnalmotors

[Wxman]

20 hours ago, nocturnalmotors said:

Is there a GM source that states what type of fluid to use in the front and rear gearcases? My manual states see dealer.

 

Edit: found in the sticky done by newdude.

Yes, newdude's info agreed with what my dealer parts/service people told me.  They also told me that if I had them do it they normally used the 75w90 in both front and rear.  I bought and used the 75w85 front and 75w90 rear.  Almost free using the reward points from truck purchase.