When and why to change diff fluid?
- Thread starter 02s4audi
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What is your driving style? Hard towing would require changing earlier than normal. Each vehicle is different and works the diff in their own way. I would be changing now.
http://www.popularmechanics.com/cars/how-to/g1140/how-to-care-for-your-cars-differential/
http://www.popularmechanics.com/cars/how-to/g1140/how-to-care-for-your-cars-differential/
No fluid last forever
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Some people never change it and never have issues. I change mine early in a new vehicle at around 10K to dump the wear in metals and again around 100K and every 50-75K thereafter--but I typically tow quite a bit. Take a look at my 2010 Ford FX4 Rear Axle UOAs paying close attention to the Fe levels. The initial change at 13K had lots of Fe (iron), the next UOA with 56,300 miles on the oil had about 66% less Fe (148 versus 429), and the final UOA with 79,689 miles on the oil had another drop in Fe despite having more miles on the oil (120 versus 148)--note the oil was changed at each UOA.
Jim Allen and others have stated the majority of the wear happens early on in an axle's life and there is merit to changing it early. Since you have never changed it, and Fe is cumulative, your iron levels are likely high and the other thing to consider is the acidity of the oil (shows up as a TAN--total acid number) in the UOA can rise as well leading to increased wear. With nearly 150K on the oil, if it were mine, I would change it--especially if you are planning to keep the vehicle. There will be many suggestions on what oil to use and you will need to decide what is best for you. M1 synthetic gear oil is good, Amsoil synthetic is arguably the best, and there is a plethora of conventional oils which will fit the bill. Good luck!
Jim Allen and others have stated the majority of the wear happens early on in an axle's life and there is merit to changing it early. Since you have never changed it, and Fe is cumulative, your iron levels are likely high and the other thing to consider is the acidity of the oil (shows up as a TAN--total acid number) in the UOA can rise as well leading to increased wear. With nearly 150K on the oil, if it were mine, I would change it--especially if you are planning to keep the vehicle. There will be many suggestions on what oil to use and you will need to decide what is best for you. M1 synthetic gear oil is good, Amsoil synthetic is arguably the best, and there is a plethora of conventional oils which will fit the bill. Good luck!
After seeimg the condition of 5 year old gear oil that came out of my truck ill be changing every 2 years or 30k miles.
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Rear end repairs can hit 4 digit money after they made a good day bad.
Old school was 30k - many choose 50k to be safe - some 100k (comfort zones)
while lubes are way better - diffs are complicated (Lockers etc) ...
Mobil Delvac 1 is another you can run a looooong time ...
Old school was 30k - many choose 50k to be safe - some 100k (comfort zones)
while lubes are way better - diffs are complicated (Lockers etc) ...
Mobil Delvac 1 is another you can run a looooong time ...
I do 30k-50k miles in my 80s GM's. Maybe a bitinger if they stay really clean looking.
Originally Posted By: 02s4audi
I have a 04 silverado 1500 with 146k on it. I'm wondering if, when, and why I should change my diff fluid?
If you are going to keep it for another 100k then change it.
I have a 04 silverado 1500 with 146k on it. I'm wondering if, when, and why I should change my diff fluid?
If you are going to keep it for another 100k then change it.
If it's never been changed, change it now.
Ford says to never change the rear axle lubricant. My 2012 F-250 is on original fluid at 87K. I plan to change both front & rear diff fluid around 100K.
If you tow really often then I would shorten that to 50K-60K.
Ford says to never change the rear axle lubricant. My 2012 F-250 is on original fluid at 87K. I plan to change both front & rear diff fluid around 100K.
If you tow really often then I would shorten that to 50K-60K.
New seals at the ready!
I have never asked anyone what they do but I changed the dif fluid in my 03 V8 4Runner a few thousand miles after delivery then 60K and 120K miles and will change it again at 180K
I use Red Line because the dif does not take much oil and the higher price is no problem and I want it to last as long as possible. I drive off road a lot and tow a heavy trailer, often in the desert where temps are a bit high.
I use Red Line because the dif does not take much oil and the higher price is no problem and I want it to last as long as possible. I drive off road a lot and tow a heavy trailer, often in the desert where temps are a bit high.
As I intend to keep my Frontier as long as it's practical I dumped the factory manual trans and differential fluid at 7500 miles. You can see that the magnetic drain plugs captured quite a lot. I'll probably do the next change at 50k and every 50k after. The fluid does break down a little with time and it becomes contaminated with Fe. It has been shown with big trucks that while the gear life is fine with conventional fluids the seal life is extended with synthetics. So I chose Red Line.
Originally Posted By: Joshua_Skinner
I figured 7500 miles was a fair break in interval for the gearboxes so I bought $101 worth of Red Line 75W-90 GL5 and MT-85.
I was pleased to find that Nissan fitted the drain plugs with magnets. The magnets caught quite a bit of wear metals, but the drain pan showed that they didn't catch everything. If this maintenance saves even one seal then the money and time were well spent.
First the rear axle drain plug.
The transmission drain plug.
And a clean plug for reference.
Originally Posted By: Joshua_Skinner
I figured 7500 miles was a fair break in interval for the gearboxes so I bought $101 worth of Red Line 75W-90 GL5 and MT-85.
I was pleased to find that Nissan fitted the drain plugs with magnets. The magnets caught quite a bit of wear metals, but the drain pan showed that they didn't catch everything. If this maintenance saves even one seal then the money and time were well spent.
First the rear axle drain plug.
The transmission drain plug.
And a clean plug for reference.
the best thing to do is to change it early in life, after break in; to get the wear metals out. I believe a study was done by Amsoil to support that. after that, I suppose I would change every 100k. I believe my Jeeps and Dodge call for 12-15k change intervals if towing - which seems like overkill.
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+1
Seen many times the early change yields oil that sparkles in the sun ...
I like to put on an aftermarket cover at this stage for several reasons ...
Seen many times the early change yields oil that sparkles in the sun ...
I like to put on an aftermarket cover at this stage for several reasons ...
Kestas
Staff member
I have similar experience with gear oil changes. The first change yields lots of fine metal debris, to where the oil looks like metallic paint. Subsequent changes - not so much. I believe diff and transfer case fluid should be changed early - like 5K - to get the break-in debris out. Then go with a schedule you can live with, somewhere between 30K and 100K intervals.
My 2006 Toyota Prado calls for 40,000 km diff oci (front and rear).
Is it just me or does that seem crazy short?
Is it just me or does that seem crazy short?
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$50 site donor 2024
Couple ways to look at it based on average length of ownership:
1. Change it early? - changed it for me - got a feel for condition - selected fluid
2. Change it late? - might have changed it for someone I don't know yet/or ever
1. Change it early? - changed it for me - got a feel for condition - selected fluid
2. Change it late? - might have changed it for someone I don't know yet/or ever
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