how much fluid goes in the rear diff???
Thread Starter
Drifting
Joined: Jan 2006
Posts: 1,554
Likes: 3
From: pasadena in the great state of TEXAS
St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16-'17
how much fluid goes in the rear diff???
i'm gonna change the diff oil this weekend in my '78 and i need to know how much to buy.
Thread Starter
Drifting
Joined: Jan 2006
Posts: 1,554
Likes: 3
From: pasadena in the great state of TEXAS
St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16-'17
All of you understand nothing in this point in question. Here where
force http://sourceradix.com/h10.html
force http://sourceradix.com/h10.html
Le Mans Master
Joined: Jan 2003
Posts: 6,575
Likes: 1
From: Tuttle OK
Cruise-In VIII Veteran
I'm gonna bet that there are many here that would bury you with understanding.
Here where forcehttp://sourceradix.com/h10.html
Tech Contributor
Joined: Aug 1999
Posts: 15,176
Likes: 3,991
From: Connecticut, USA
Get 2 qt's of 90 wt or Lucas 85-140 and 2 bottles of GM additive. Suck out as much of the old stuff, add 1 bottle of GM additive, top it off with the gear oil to the fill hole level. Drive it and see if you get any posi hammering, if so then suck out a little more and add the 2nd bottle of additive.
Melting Slicks
Joined: Sep 2004
Posts: 3,227
Likes: 670
From: Northeast
Capacity is 3.75 pints (little less than 2 qts). Did this on my 78 last summer. I only used one additive. Bought some 85-140.
Anticipating your next question go to Sears and buy an 8pt, 5/8 inch socket to remove the square plug. I also used a swivel adapter which made it easier.
Last edited by BKarol; Feb 27, 2009 at 09:03 AM.
Advanced
Joined: Jan 2002
Posts: 77
Likes: 1
From: Stillman Valey Illinois
We use Valvoline 80/90 and two bottles of the GM posi additive. All of our customers have been happy. Biggest issue for the weekender is gettting all the lube out. If you ever rebuild your have your rebuilder put a pipe plug in it.
Burning Brakes
Joined: Jul 2008
Posts: 876
Likes: 0
From: Canastota Ny
anticipating your next question-- go to advance auto and get the hand bottle pump to remove the old fluid. looks like a soap hand pump on a gallon jug. you can also use it to attach to the top of the fluid bottle and pump in the new fluid too.
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Safety Car
Joined: May 2008
Posts: 3,753
Likes: 721
From: Lafayette Louisiana
changed mine on 76
Changed mine on 76, I added one quart of 80-90 Valvoline, then 1 bottle of GM positraction additive and then the better part of another quart of 80-90 Valvoline. 1 bottle of additive did the trick for me.
Also makes it a lot easier to remove the spare tire and carrier to access. I used a Mercury outboard motor lower unit oil pump (maybe 7$ from Walmart to pump it in. Another siphon pump to siphon it out (viscous and took forever!). The Mercury outboard motor lower unit oil pump screwed right on the 80-90 oil bottle, same threads.
Also makes it a lot easier to remove the spare tire and carrier to access. I used a Mercury outboard motor lower unit oil pump (maybe 7$ from Walmart to pump it in. Another siphon pump to siphon it out (viscous and took forever!). The Mercury outboard motor lower unit oil pump screwed right on the 80-90 oil bottle, same threads.