Every 50k to 60k on my hotshot fleet
How often do you change rear diff fluid
- Thread starter wheelman
- Start date
How do you select the change interval? Are you testing the fluid?
Going back several generations on the farm, with lesser fluids in the old days, this stuff would go decades without being done, in severe service, extreme cold, and nary an issue.....
Myself, I like to change the fluids at a reasonable interval but most folks who never, ever do it don't experience any issues at all....
After initial 15ish k mi, every 50k seems reasonable. Gives me something fun to do since my truck doesn't see heavy use ( tow under 1% total use), and don't haul over 2 tons. I do pull the plugs about every oil change and clean the magnets though. I'd still shoot for 50k if I used it to its full potential. If it had clutches, maybe a touch sooner.
No testing, they all last 500k plus so no need to test as most don't show much wear with these changes. Never had to replace a rear.
A time interval would be appropriate...
I swear the Dana diff oil I changed at 60k (when I bought it in 2020) was OEM from 1971. Inches of sludge and some tube surface wear at the hub oil seal contact. I was too disgusted to take a pic.
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- Jun 8, 2022
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I change my Nissans front and rear diff (along with the transfer case) around 30K each. Probably overkill. They all have drain plugs so other than the cost its really not much of an encumbrance. The front diff - which also holds the least amount of fluid - like 1 quart, specs 85w-90 which is a dyno oil. I have wondered if I should just switch it to a 75w-90 syn and run it longer, but in the end the cost would be about the same since the dyno stuff is 1/2 the price.
60-100k miles
The 2022 Chevy Silverado has a special set of maintenance requirement for severe service. In severe service, changing out rear end gear lube is still not a required service. How often? Never.
And here is the maintenance intervals, for severe service, for Chevy 2500 and 3500’s. The rear diff is just not a maintenance item for them.
JHZR2
Staff member
I’ve found that to be an issue. Lack of use results in lack of heat, which results in moisture. It’s unique to the front diff IME.
And because of this, probably a cheaper and/or more water protective fluid is preferred. I stayed with conventional in front diffs for that reason, despite going with syn in the rears.
JHZR2
Staff member
Much older vehicle, but IIRC my S-10 ZR2 manual said that for the LSD to do it at 7500 miles then no recommendation unless there was an issue.
My 3500 manual says, "For vehicles with the limited-slip differential, driven under severe conditions, the rear axle fluid should be changed. See Maintenance Schedule page 384".
On page 384 you'll find:
The Additional Required Services - Severe are for vehicles that are:
- Mainly driven in heavy city traffic in hot weather
- Mainly driven in hilly or mountainous terrain
- Frequently towing a trailer B]
[*]Used for high speed or competitive driving.
[*]Used for taxi, police, or delivery service
Next is says to: Refer to the information in the Maintenance Schedule Additional Required Services - Severe chart.
The end result is that GM give zero recommendation about when the differential fluid should be changed. I've looked all over the Maintenance section of the manual and the maintenance section of the Diesel Supplement manual and there is nothing about changing the differential fluid. I wonder why they did this?
At 50 to 60k of heavy towing (always hooked up to a 40ft gooseneck) fluid is not crazy bad bit needs a change. I rather change it 10 times in its life then need to replace a rear.
1995 Prevost XL40' bus/mh that weighs 41k to 51k Lbs depending on what it's towing. 65 mph. Rockwell Intl rear end/differential.
Changed it 9 yrs ago at 69k miles with 4.5 gals of Amsoil 75w-90 when we purchased it, and again recently at 113k miles with a 66/34 mix of Amsoil Long Life 75w-90 and severe gear 75w-110. No issues.
Waiting on UOA sample results.
Changed it 9 yrs ago at 69k miles with 4.5 gals of Amsoil 75w-90 when we purchased it, and again recently at 113k miles with a 66/34 mix of Amsoil Long Life 75w-90 and severe gear 75w-110. No issues.
Waiting on UOA sample results.
I'm assuming the filter is for the differential? If so, did you cut the old filter to see what was in it?
I did the first differential change on both my Jeeps at 10K miles along with the transmission fluid and transfer case fluid. The transmissions get serviced every 30K after that, and the differentials every 50K. I used Mobil 1 gear oil in the differentials. 75W90 in the front and 75W140 in the rear. Everything looked fine in both vehicles.
I just changed the OE rear differential fluid on my daughter's 21' Mazda CX-30 at 25300 miles....it looked very clean. I used RP Maxlife 75w90. There was a little fuzz on the magnet so I cleaned it up. I'll probably go 40 or 50k on this fill.
