Rear diff fluid level? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Kiwi · 09-29-2010, 02:43 PM

I have a 1971 Chevrolet C10 (2WD, long bed) that is fit with a leaf-spring suspended rearend with 12 bolts for the rear cover (versus 10 bolts used on some trucks).

1. Does anyone know what the proper weight diff oil should be?

2. Does anyone know how much oil is required?

I called the local Chevrolet dealer and he said his books didn't go back to the early 1970s ... so I'm looking for some info.

**68350** · 09-29-2010, 02:54 PM

I used 80-90 or 85-130(i think thats the wieght). Add posi lube if you have a posi. Prolly take 3 or 4 quarts.

**Stocker** · 09-29-2010, 03:33 PM

90 weight when these trucks were new.... most people now use 80W-90 or 75W-90, either dino or synthetic. Fill until it reaches the bottom of the threads on the fill plug (parked on a level surface).

Kiwi · 09-29-2010, 04:48 PM

Stocker,

Any idea about how much oil "Fill until it reaches the bottom of the threads on the fill plug" is?

I'd like to know how much oil to buy so that I don't have to make a second trip to the parts store.

eightbanger · 09-29-2010, 05:13 PM

I get 3 bottles of 80W-90 GM axle lubricant which each contain 23fl oz and one small bottle of additive as I have a posi, and I use 2 1/2 bottles plus the additive to fill mine.
Hope this helps.

**Stocker** · 09-29-2010, 05:19 PM

I'm not sure, but I'll poke around the board, maybe there's info posted somewhere. I'd guess maybe 3 quarts. I usually buy more than I need and save the receipt so I can return unopened, unused stuff -- or just put it on the shelf for next time.

Edit: maybe this will help: http://67-72chevytrucks.com/vboard/s...d.php?t=219680

*Shane* · 09-29-2010, 06:12 PM

buy 4 bottles ... then take one back if it only holds 3

09-29-2010, 02:43 PM	#1
Kiwi Registered User Join Date: Mar 2010 Location: Los Angeles, California Posts: 81	Rear diff fluid level? I have a 1971 Chevrolet C10 (2WD, long bed) that is fit with a leaf-spring suspended rearend with 12 bolts for the rear cover (versus 10 bolts used on some trucks). 1. Does anyone know what the proper weight diff oil should be? 2. Does anyone know how much oil is required? I called the local Chevrolet dealer and he said his books didn't go back to the early 1970s ... so I'm looking for some info. Last edited by Kiwi; 09-29-2010 at 02:44 PM.

09-29-2010, 02:54 PM	#2
68350 Senior Member Join Date: Jan 2002 Location: Williston, ND Posts: 2,999	Re: Rear diff fluid level? I used 80-90 or 85-130(i think thats the wieght). Add posi lube if you have a posi. Prolly take 3 or 4 quarts. __________________ 68 Chevy CST/10, 50th Anniversary, 327/th400, 373 posi, buckets 68 GMC Shortbox Stepside, 402/th400, Tilt, Tach, Bucket Seats, 3.08 Positraction 69 Chevy Camaro SS, 383, 4 speed, positraction 70 Chevy El Camino SS396, Triple Black, 454/th400, Tach 70 Chevy Shortbox Stepside 4x4, 350/th350, Tilt, Tach, Cab Lights, Bumper Guards, Tow Hooks 70 Chevy 3/4 Longbox, 350/auto, 70k, SURVIVOR 71 Chevy Blazer, CST, 350/auto 71 GMC Sierra K2500, 454, 4 speed, 4.10 posi, 37s 71 Custom/30, Open Road, 350/th400, tilt 72 Chevy Shortbox Fleetside, 496 Stroker/th400, Tilt, Tach, Bucket Seats, 3.42 Posi 72 GMC Sierra Grande 2500. 427/th400, tilt, a/c, tool and stowage, buckets/console, 3.54 posi

09-29-2010, 03:33 PM	#3
Stocker 20' Daredevil (Ret) Join Date: May 2003 Location: Jefferson State Posts: 13,648	Re: Rear diff fluid level? 90 weight when these trucks were new.... most people now use 80W-90 or 75W-90, either dino or synthetic. Fill until it reaches the bottom of the threads on the fill plug (parked on a level surface). __________________ - Mike - 1972 K20 LWB 350/350/205 RIP El Jay

09-29-2010, 04:48 PM	#4
Kiwi Registered User Join Date: Mar 2010 Location: Los Angeles, California Posts: 81	Re: Rear diff fluid level? Stocker, Any idea about how much oil "Fill until it reaches the bottom of the threads on the fill plug" is? I'd like to know how much oil to buy so that I don't have to make a second trip to the parts store.

09-29-2010, 05:13 PM	#5
eightbanger 454 MAKES IT ROAR Join Date: Jan 2008 Location: Essex, U.K Posts: 2,701	Re: Rear diff fluid level? I get 3 bottles of 80W-90 GM axle lubricant which each contain 23fl oz and one small bottle of additive as I have a posi, and I use 2 1/2 bottles plus the additive to fill mine. Hope this helps. __________________ Nigel. An American living in a British body. 1971 Chevy Cheyenne 10 454 "In a time of universal deceit, telling the truth becomes a revolutionary act." - George Orwell "When injustice becomes law, resistance becomes duty" - Thomas Jefferson No more pain. 03.12.60 -- 12.28.10 http://www.youtube.com/Eightbanger

09-29-2010, 05:19 PM	#6
Stocker 20' Daredevil (Ret) Join Date: May 2003 Location: Jefferson State Posts: 13,648	Re: Rear diff fluid level? I'm not sure, but I'll poke around the board, maybe there's info posted somewhere. I'd guess maybe 3 quarts. I usually buy more than I need and save the receipt so I can return unopened, unused stuff -- or just put it on the shelf for next time. Edit: maybe this will help: http://67-72chevytrucks.com/vboard/s...d.php?t=219680 __________________ - Mike - 1972 K20 LWB 350/350/205 RIP El Jay Last edited by Stocker; 09-29-2010 at 05:27 PM.

09-29-2010, 06:12 PM	#7
Shane Account Suspended Join Date: Jun 2000 Location: over yonder Posts: 14,270	Re: Rear diff fluid level? buy 4 bottles ... then take one back if it only holds 3



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