lubrication question.....

[BIG CHEVY]

EXACTLY WHAT KIND OF LUBE DO YOU PUT IN THE REAR CHUNK OF MY TRUCK? ALSO DO BOTH TAKE THE SAME THING?

I HAVE A 79 K-10 WITH NP 203.    NEW TO ME SO I AM GONNA MAKE SURE ITS DONE RIGHT SO FOR PEACE OF MIND

I WANT TO BE IN AGREEANCE WITH ALL OF YOU.  THANKS GUYS.

[VileZambonie]

Do you mean the read end? 80w90

[BIG CHEVY]

YES BOTH REAR AND FRONT.   ALSO THE FRONT HAS A DRAIN PLUG AND A HOSE COMING OUT OF THE TOP.
THE REAR HAS NO PLUG AND THE SAME HOSE COMING OUT THE TOP.   WHAT GOES IN EM?   AND WHAT ARE THOSE HOSES?
HOW DO I CHECK THE REAR OR ADD/REPLACE?

[VileZambonie]

Those are both 80w90. If it's a posi in the rear you'll need limited slip additive. The hoses on top are breathers and they just vent the housings. Just remove the fill/check plug on level ground. the level should be just about to the bottom of the fill plug. The fill/check plug on the rear is not on the cover, it's on the front side and is a 3/8" drive square so just use a 3/8" ratchet to remove it. Make sure you clean around the check plug before you remove it.

[Blazin]

You can drain them and replace with synthetic oil.
By the way all caps. is considered yelling!