New Guy Question

[mollyman]

I've got an 81 K10 Sub I'm "restoring". I've got the axles out from under the truck and am cleaning them up. What is the best way to change the diff fluid? Should I take the cover off and tilt it up and let it poor out? If so do i put a new gasket or some kind of sealer from a tube to put the diff cover back on? The front is a 10blt the rear 12blt if that matters. Or should I use the plug? And how do you fill them back up, through the plug. And what's the best fluid. One last thing, this will be the first time this fluid has ever been changed and currently neither diff leaks at all!!! Any help would be great!! And I appreciate everyone who has answered my questions before and for not making fun of a new guys questions!!!

 

[Cricket]

Take the cover off to drain it and inspect for any damage / metal particles / water in the lube / et.

Once that's been done clean the gasket surfaces until you can eat off them. Make sure the cover flanges are straight. Reassemble with a new gasket or go buy a can of "The Right Stuff" gasket maker. Do not use silicone gasket maker, it will leak.

Use 80w/90 gear lube and refill the differential through the fill plug hole. You can buy a hand pump for gear oil down at the parts store. I usually just pour the gear oil in a clean can or cup then pump it in until the lube wants to leak back out of the fill hole.