Differential fluid change ?

[first]

If I were to change the fluid I know it has to sucked out at the fill plug, I looked in the Helms for fluid type and capacity, unless I missed it it only shows a lube tag location on the tranny so I guess it may give the info there but what about the posi-trac additive How much?. I’m sure the answer is on this site. It’s a 6-speed with 47k.Thought maybe I would change the fluid along with the coolant and tranny fluids.I just bought the vette last year.

[c4ever]

Owners manual will give correct fluid type and capacities. 1 part additive is required and can be had at any Chevy dealer.

Carlo

[jsinga]

I used a qt bottle of oil and mixed in the posi additive.
We drilled a hole in the back of the rear end case and threaded the hole for a magnetic plug now I dont have to try and suck the stuff out.

JS

[first]

Thanks for the input,Has anyone out there tried sucking the fluid out and if so how hard was it .Any tips ?