Servicing the C3 Differential
Thread Starter
Racer
Joined: Jul 2003
Posts: 460
Likes: 18
From: Conroe, TX
Servicing the C3 Differential
So, yesterday I was under my '82 finishing up installing new rear SS brake calipers and SS lines along with new Bilstein Sports, and I casually started to think about one of my next tasks, which is changing out the gear oil in the differential. I crawled under the pumpkin area looking for the drainplug thinking it would be just like my C5. No drain plug to be found! 
I'm pretty lazy, so there's no friggin' way I'm pulling down the entire rear suspension to remove the inspection cover, I'll buy/borrow one of those vacuum purge units before that; but I'm just wondering what other C3 owners do when its time to change the differential fluid??
There has to be an easier way!
I'm pretty lazy, so there's no friggin' way I'm pulling down the entire rear suspension to remove the inspection cover, I'll buy/borrow one of those vacuum purge units before that; but I'm just wondering what other C3 owners do when its time to change the differential fluid??
There has to be an easier way!
Melting Slicks
Joined: May 2004
Posts: 2,738
Likes: 837
From: Gulf of America
2023 C7 of the Year Finalist - Unmodified
2018 C3 of Year Finalist
I suck out the oil with one of those things that looks like a oversized hypodermic needle available at your local auto store. Also use it to refill. In this month's issue of Corvette Fever is an article on drilling and tapping for a diff drain plug if your're interested. Appears the kit comes with a template to locate where to drill.
Thread Starter
Racer
Joined: Jul 2003
Posts: 460
Likes: 18
From: Conroe, TX
Thanks guys for the replies! I'll stop by my favorite Auto Zone and see if I can buy one of those suction pumps and drain the fluid through the fill hole. I'm looking forward to that mess!! 
Le Mans Master
Joined: Jan 2001
Posts: 6,938
Likes: 1
From: San Diego CA
No big deal. I have a brake bleeder pump for $15 from Autozone which I use for brakes, sucking out differential/ tranny fluid etc. etc. Easy to do no mess just about 20 minutes from start to finish.
