Rear Differential Fluid
Thread Starter
Le Mans Master
Joined: Oct 2006
Posts: 8,940
Likes: 35
From: El Cajon California
Rear Differential Fluid
I buy some stuff from Ecklers but I know I can find this cheaper,
I can get their rear differential fluid kit, axle fluid, posi additive and gasket for 68.89 + 17.00 for shipping.
Can't I get a gasket, fluid and special sauce from Autozone or Summit Racing?
In addition what kind of rear end do we have in a 1978 Corvette? I want to get the right gasket.
I can get their rear differential fluid kit, axle fluid, posi additive and gasket for 68.89 + 17.00 for shipping.
Can't I get a gasket, fluid and special sauce from Autozone or Summit Racing?
In addition what kind of rear end do we have in a 1978 Corvette? I want to get the right gasket.
Race Director
Joined: May 2006
Posts: 18,707
Likes: 2,573
the Ecklers kit assumes you are somehow going to remove the back cover to drain the fluid. The majority of people do not do it that way.
You suck the old fluid out with a pump and pour in the gear oil and additive.
Summit Racing should have the gear oil and additive.
You suck the old fluid out with a pump and pour in the gear oil and additive.
Summit Racing should have the gear oil and additive.
Thread Starter
Le Mans Master
Joined: Oct 2006
Posts: 8,940
Likes: 35
From: El Cajon California
Is it best to pull the differential cover off, let that nasty old fluid drain and spray the gears with Berryman B-12 carb cleaner.
Bolt the cover back on with a new gasket then fill the rear end?
As opposed to sucking out the fluid and filling back up?
Bolt the cover back on with a new gasket then fill the rear end?
As opposed to sucking out the fluid and filling back up?
Melting Slicks
Joined: Nov 2001
Posts: 2,668
Likes: 43
From: Eastern US XX
10 year "Corvette" forum member and you present this?
Hmmm........
Hmmm........
2026 Loser of the Year
Joined: Sep 2013
Posts: 36,579
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From: New Or-leens Loo-z-anna
I wouldn't use carb cleaner on the gear assembly----it would probably get into the bearings and strip all the gear oil off the rollers......
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Race Director
Joined: May 2006
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Rear Cover
Have you seen what is all connected to the rear cover?
The cover holds the differential to the cross member.
The spring, camber bracket, etc. attach to the bottom of the cover.
Melting Slicks
Joined: May 2011
Posts: 2,753
Likes: 119
From: Springfield Missouri
there was an article on how to drill the diff on the bottom and tap the hole for a plug while it was still in the car, may of been in "Corvette Fever" magazine a long time ago, anyone done this? it looked very easy if you have the correct tools.
Racer
Joined: Mar 2011
Posts: 490
Likes: 99
From: The South
I would think it would be easier/cheaper just to invest $70 in a Mityvac fluid evacuator and suck it out the fill hole. That's what I did anyway.
Last edited by gguillot; Dec 13, 2016 at 04:14 PM.
Racer
Joined: Jul 2013
Posts: 366
Likes: 19
Go to your local Chevy dealer, buy GM fluid, and two 4 oz bottles of additive. If you can, drive your a car a bit to warm up the rear fluid. Buy a fluid pump, or a turkey baster, and tubing works. (Takes a while) The fluid really stinks! Careful the tubing doesn't slip off. Gloves and eye protection. Add the fluid until it seeps out of the plug hole. Done.
Thread Starter
Le Mans Master
Joined: Oct 2006
Posts: 8,940
Likes: 35
From: El Cajon California
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
Process:
1. Break the 'fill' pipe plug loose, then retighten a bit.
2. Drive car for 10 miles (or so) to warm up lube in the diffy.
3. Park in garage and jack rear to get access; remove 'fill' plug.
4. Use syphon [squeeze bulb & plastic tubing] to suck out all the diffy lube possible. (Good 'nuf)
5. Fill diffy with one bottle of rear gear lube; then add the bottle of Posi-Trac additive; top off with some of another bottle of lube [until it begins to run out of 'fill' hole].
6. Install fill plug and tighten to 15 ft-lbs. If you cleaned the threads of all lube, tighten to 20 ft-lbs..
7. DONE! Have a beer!
(Didn't cost that much, did it? Forget the Eckler's purchase.)
1. Break the 'fill' pipe plug loose, then retighten a bit.
2. Drive car for 10 miles (or so) to warm up lube in the diffy.
3. Park in garage and jack rear to get access; remove 'fill' plug.
4. Use syphon [squeeze bulb & plastic tubing] to suck out all the diffy lube possible. (Good 'nuf)
5. Fill diffy with one bottle of rear gear lube; then add the bottle of Posi-Trac additive; top off with some of another bottle of lube [until it begins to run out of 'fill' hole].
6. Install fill plug and tighten to 15 ft-lbs. If you cleaned the threads of all lube, tighten to 20 ft-lbs..
7. DONE! Have a beer!
(Didn't cost that much, did it? Forget the Eckler's purchase.)
Last edited by 7T1vette; Dec 20, 2016 at 12:08 AM.
Drifting
Joined: Oct 2012
Posts: 1,524
Likes: 61
From: Medina Ohio
The only concern with it being in the car is getting the drill shavings out. I suppose if you flushed the diff real well and let a fair amount of fluid run out the drain hole you'd be OK.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
Total waste of time and effort, if you just follow the procedure above. You only change rear-end fluid every 5 years (or so); is that worth risking the integrity of a 'sealed' unit? I don't think so....