Diff oil change without removing the cover
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Diff oil change without removing the cover I have a 2002 Firehawk. The diff oil has been changed 5 years ago. The car has been barely driven (only around 600 miles) since then, but I want to change the fluid due to age. The diff cover is NOT leaking.
This is one of my "forever" cars and is in a near-new condition. I do not have access to a lift or to a good mechanic I can trust.
The question is: can I use a automotive fluid extractor pump (like this one on Amazon https://a.co/d/05cuVDHc) to suck the fluid out through the fill plug and then refill the diff with new fluid? I realize that some of the old fluid will remain in the diff, but I am going to try to get the tube to the bottom of the diff, so most of the fluid will come out.
This is one of my "forever" cars and is in a near-new condition. I do not have access to a lift or to a good mechanic I can trust.
The question is: can I use a automotive fluid extractor pump (like this one on Amazon https://a.co/d/05cuVDHc) to suck the fluid out through the fill plug and then refill the diff with new fluid? I realize that some of the old fluid will remain in the diff, but I am going to try to get the tube to the bottom of the diff, so most of the fluid will come out.
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Interesting what information is becoming available to us. One thing interesting is how older fluids lose their anti-frothing agents overtime. Aerated oil doesn’t lubricant well so time alone warrants fluid change. Plenty of videos depicting this phenomenon that we enthusiast should be privy to.
change ur fluids often folks. It could save u a headache later.
change ur fluids often folks. It could save u a headache later.
Last edited by Finkledbody; Jun 24, 2024 at 07:28 PM.
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From: Schiller Park, ILL Member: #317
As this is a Firehawk, it might have been optioned with the Auburn diff (this is just something to be aware of regarding lube selection). If not, the standard factory recommendation of 75w90 synthetic is fine for the Torsen LSD.
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Combustion gases is not what breaks down anti-frothing agents. Time allows the anti-frothing agents to absorb into the oil. Once that happens the oil will aerate and you lose lubrication.
This can be tested by anyone but Check out The Motor Oil Geek on YouTube. He does a simple test where he takes brand new motor oil that has been sitting in a shop for 10-20 years. He uses a frothier on the old oil and shows how the bubbles don’t go away. The oil is fresh by every measure but the anti-frothing agents no longer work. Bubbles are the death of metal components as it’ll introduce heat and premature wear.
Gear lube will also have anti-frothing agents that will too absorb over time. How much time is the question. A simple test could determine if the fluid is still good.
This can be tested by anyone but Check out The Motor Oil Geek on YouTube. He does a simple test where he takes brand new motor oil that has been sitting in a shop for 10-20 years. He uses a frothier on the old oil and shows how the bubbles don’t go away. The oil is fresh by every measure but the anti-frothing agents no longer work. Bubbles are the death of metal components as it’ll introduce heat and premature wear.
Gear lube will also have anti-frothing agents that will too absorb over time. How much time is the question. A simple test could determine if the fluid is still good.
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From: Schiller Park, ILL Member: #317
Combustion gases is not what breaks down anti-frothing agents. Time allows the anti-frothing agents to absorb into the oil. Once that happens the oil will aerate and you lose lubrication.
This can be tested by anyone but Check out The Motor Oil Geek on YouTube. He does a simple test where he takes brand new motor oil that has been sitting in a shop for 10-20 years. He uses a frothier on the old oil and shows how the bubbles don’t go away. The oil is fresh by every measure but the anti-frothing agents no longer work. Bubbles are the death of metal components as it’ll introduce heat and premature wear.
Gear lube will also have anti-frothing agents that will too absorb over time. How much time is the question. A simple test could determine if the fluid is still good.
This can be tested by anyone but Check out The Motor Oil Geek on YouTube. He does a simple test where he takes brand new motor oil that has been sitting in a shop for 10-20 years. He uses a frothier on the old oil and shows how the bubbles don’t go away. The oil is fresh by every measure but the anti-frothing agents no longer work. Bubbles are the death of metal components as it’ll introduce heat and premature wear.
Gear lube will also have anti-frothing agents that will too absorb over time. How much time is the question. A simple test could determine if the fluid is still good.
I would absolutely not worry about 5 year old/600 mile gear lube in a non-racing application, unless maybe the car had been stored in a terrarium. Personal experience with many old, RWD cars tells me this is not going to be a problem, but obviously it's up to the owner to do whatever he feels is best.
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Verdad Gallardo In all the (20+) cars I've owned over the years, I've never seen any manufacturer recommend differential fluid changes based on time and not mileage. I can't imagine a heavy, sticky lube like gear oil would not leave a protective film on the metal parts that would magically disappear and leave both metal surfaces bare to grind against each other when an air bubble was encountered. Sorry, not happening.
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In all the (20+) cars I've owned over the years, I've never seen any manufacturer recommend differential fluid changes based on time and not mileage. I can't imagine a heavy, sticky lube like gear oil would not leave a protective film on the metal parts that would magically disappear and leave both metal surfaces bare to grind against each other when an air bubble was encountered. Sorry, not happening.
Perhaps we should learn more here
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When I first got my ‘00 Z28 two years ago I sucked out what I’m assuming was the original fluid through the fill hole and it had 27k miles on it at that time. The fluid that came out was almost a lime green color. It looked pretty bad so I did two suck and fills. The pinion seal was leaking at that time so I bet the green tint came from moisture getting in. Later down the line I took the cover off and all was well inside. If not for the leaky seal I bet the oil still would’ve been good.
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TECH Fanatic
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In all the (20+) cars I've owned over the years, I've never seen any manufacturer recommend differential fluid changes based on time and not mileage. I can't imagine a heavy, sticky lube like gear oil would not leave a protective film on the metal parts that would magically disappear and leave both metal surfaces bare to grind against each other when an air bubble was encountered. Sorry, not happening.
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I wasn't referring to anti-frothing; just that engine oil which has been "used" (even if only a small amount) will contain combustion byproducts which can prove harmful to internal components over long periods (such as sitting for many years). This is not an issue for gear lube, as no combustion should be taking place in the differential.
Last edited by Y2K_Frenzy; Jun 25, 2024 at 09:26 PM.
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From: Schiller Park, ILL Member: #317
In all the (20+) cars I've owned over the years, I've never seen any manufacturer recommend differential fluid changes based on time and not mileage. I can't imagine a heavy, sticky lube like gear oil would not leave a protective film on the metal parts that would magically disappear and leave both metal surfaces bare to grind against each other when an air bubble was encountered. Sorry, not happening.
