Rear diff fluid change

[billdogg5]

3.91 rear end in my 74 challenger, whats the easiest way to change the gear oil? My first time doing in and looking for pointers, thanks in advanced!

[Burdar]

https://forum.e-bodies.org/engine-transmission-and-rear-end/4/how-to-change-differential-fluid-on-this-rear-end/19093/msg243780#msg243780

[billdogg5]

Exactly what I'm looking for!
Thanks!

[Suregrip391]

I just did this in my 70 Challenger..... remove the fill plug, suck out old gear oil with one of those $4-$10 hand pumps from harbor freight or hardware store, add friction modifier if you have a Suregrip, then add the new 80w90 gear oil GL5 rated from Walmart made by Supertech, it's $5 a quart & Highly recommended by Dr. Diff. Add the new gear oil until you see it pouring back out that same fill hole. Install plug and Done! Does not take long at all.

[billdogg5]

Thanks that's exactly the info I need!