eddp

A little Sunday project. First time changing the diff fluid on the '81. Don't have the bottom drain plug,, why not?? Another genious design!
My hose from the fluid pump isn't really flexible and doesn't appear to bend down; only to the front of the diff.
Is the trick to raise the rear so that the fluid pools as far forward in the diff?

Gunfighter13

Designed to change fluid when clutch packs are serviced. No need for a drain plug.

eddp

Just curious? How often are the clutch packs supposed to be serviced? Doesn't that require dropping the carrier and diff? And then basically rebuilding the diff?

interpon

Put a wire coat hanger or some support on the suction hose, thats what i used and left the soft part extend a couple inches to poke around and pump out what you can..worked pretty good

eddp

Thanks for the advice. It took over 60 oz. including 4 oz of LSA.

interpon

If you have any room, i put 2 , 4 ounce bottles of the gm additive per this forum.

HeadsU.P.

eddp,
Why no drain plug? Lets just say for sake of argument that it wouldn't cost GM a penny to add one. However, 40 yrs later, someone would be asking:
Why does my rear axle drainplug drip?
Why does my trans - pan plug weep?

Just like an oil pan plug, it will drip. Trust me.

av81

Not saying a plug should be there but a diff plug is nothing like a oil pan plug , had a repair shop for over 23 years barley saw diff plugs leaking and when I did it was loose.

eddp

I've watched several You Tube vids on corvette diff fluid and several have had a plug at the bottom and a fill on the side of the case.

bashcraft

They all had fill plugs on the side, and if it had a drain plug, someone installed it themself.

pws69

Only one bottle is required.