Differential Fluids Question
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Joined: Jan 2010
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From: Palm Coast FL
Differential Fluids Question
Hello again fellas. For my next trick I am going to swap my 82 diff. The original one has apparently lost an inner clip which limits the travel of the right axle yoke. Since it has 219,000 miles on it and all 3 seals are leaking (which doesn't drip but slings heavy goo onto the underside which is otherwise clean) I've already purchased a slightly used diff. Once the old one is dropped I will replace some bushings on the rear suspension which have never been touched, like the bat wing bushings. My question tonight is about the fluids. Eckler's wants $105 for 2 bottles of rear axle fluid and 1 bottle of the limited slip additive. What are my alternatives to this gross cost?
Steve
Steve
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From: Cool Northern Michigan
The original GM rear axle fluid and the Posi modifier additive can be had at Amazon at maybe half of that cost. As soon as they settle their safety issues anyway
You will need two of Lg bottles and one Sm bottle of modifier. I believe the total is 56 oz or close to that to fill.
When you are ready to fill, you can mix unequal parts in a clear, plastic, squeeze bottle from a food supplier, like GFS. (think BBQ sauce bottle) All this mixing can be done on your workbench. Shake bottle.
The squeeze bottle has a nozzle tip and will require filling several times, but fits up inside the diffy area easily.
If you can't wait for Amazon, I believe Muskegon Brake also sells the lube.
Correction: my notes say 50 ounces total.
You will need two of Lg bottles and one Sm bottle of modifier. I believe the total is 56 oz or close to that to fill.
When you are ready to fill, you can mix unequal parts in a clear, plastic, squeeze bottle from a food supplier, like GFS. (think BBQ sauce bottle) All this mixing can be done on your workbench. Shake bottle.
The squeeze bottle has a nozzle tip and will require filling several times, but fits up inside the diffy area easily.
If you can't wait for Amazon, I believe Muskegon Brake also sells the lube.
Correction: my notes say 50 ounces total.
Last edited by HeadsU.P.; Apr 3, 2020 at 04:01 PM.
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From: Was New Orleans but swam to Baton Rouge LA
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I run the Lucas heavy duty with two bottles of GM additive. This is all based on the recommendation I received from Tom of Tom's Differentials.
https://lucasoil.com/products/gear-o...w-140-gear-oil
Looks like Gary recommends the same stuff. https://www.corvetteforum.com/forums...post1568498743
https://lucasoil.com/products/gear-o...w-140-gear-oil
Looks like Gary recommends the same stuff. https://www.corvetteforum.com/forums...post1568498743
Last edited by Sigforty; Apr 3, 2020 at 09:29 AM.
Disabled by request 8 JUN 2025
Joined: May 2019
Posts: 329
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From: St. Augustine, FL
Steve, I drained my differential and replaced the gear oil with Lucas 85-140 weight plus one bottle of Gm posi fluid. The Lucas is available at Discount Auto the the posi additive at your local GM dealer........Roy, (your look alike 81 dark claret neighbor)
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Joined: Jun 2019
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From: Indiana
I run the Lucas heavy duty with two bottles of GM additive. This is all based on the recommendation I received from Tom of Tom's Differentials.
https://lucasoil.com/products/gear-o...w-140-gear-oil
Looks like Gary recommends the same stuff. https://www.corvetteforum.com/forums...post1568498743
https://lucasoil.com/products/gear-o...w-140-gear-oil
Looks like Gary recommends the same stuff. https://www.corvetteforum.com/forums...post1568498743
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Joined: Feb 2020
Posts: 56
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From: South Carolina
I know you guys may cough up a fur ball, but I changed my differential fluid with 2 quarts 75w90w gear oil and a bottle of Lubeguard limited slip modifier for around 36 bucks from Oreilly's. I had a noise coming from the differential and I wasn't sure if the PO had changed it out. The noise I had is now completely gone. I was in the middle of changing out most rear bushing. I plan on doing the differential and I will replace with a different fluid. But for now the gear oil and modifier I used seems to do the trick.
Last edited by Quackster; Apr 3, 2020 at 10:13 PM.
Drifting
Joined: Apr 2020
Posts: 1,779
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From: Ocean County NJ
I run Moroso climbing gear lube in my GS 455 12 bolt which has a Moroso brute strength posi unit in it since they recommended it and its been in there a long time with no problems, noise or chatter.
Other threads on the forum said not to use it in a regular posi so I am using the delco fluid and additive when I change it in my newly bought vette
Other threads on the forum said not to use it in a regular posi so I am using the delco fluid and additive when I change it in my newly bought vette
