My F150 owners manual doesn't even specify a change requirement.
Do you follow severe differential oil change interval?
- Thread starter Elkins45
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4WD
$50 site donor 2024
Only my Jeep - but I find the GM gaskets good enough to back off bolts until they leak - then go gather oil - once nearly drained - give it a couple ounces of new oil to flush the bottom - torque and fill …You guys with drain plugs make me jealous
(clean the magnet on fill plug removed at the start) …
There is a big difference between how most passenger vehicles are used and something that really sees severe service. For a typical SUV or pickup that hauls the kids around and goes to the home center on weekends most people will never have an issue even if the differential fluid is never changed. For vehicles that are usually at max GVW and/or towing heavy, the differential service is more important. Even if the oil is only changed once that is much better than never at all.
My '97 C2500 Suburban has done a lot of towing in its life. For 20 years it towed a camper across the US 2x per year, while loaded with 4 adults and full of luggage. I have all of the service records. It did NOT have that early differential service at the first oil change, instead it needed new axles and wheel bearings when it barely had 20K miles on it. It has also had the axle seals replaced a few times since then, along with a pinion seal. Last year I popped the cover off to change the oil and inspect the gears/bearings and I was surprised at the amount of metallic goop in the bottom of the case. There is large magnet right under the ring gear, and mine looked like a rock with hair growing on it. From what I can see in the service records it only had the oil changed when the axle was repaired. I can't help but wonder if a more frequent service and a better gear lube would have prevented some of the issues.
I can also think of some farm trucks that needed work done on the rear axle. They all hauled/towed heavy and had factory fluid in the axle for the first repair.
I use Amsoil SVG and assume that gear oil will handle anything I can throw at if. But my pickup rarely tows a trailer.
My Canyon has to be on a lift for me to get to the fill plug. GM offered a couple different pumpkins on these & I got one that is a complete PITA with the fill plug too high & tucked up out of the way to get to until on a lift. I know I should be thinking if it's already on a lift just take the time to pull the rear cover & clean it correctly but I'd really like to be lazy on occasion with a drain plug lol. If I'm breaking the seal on the rear cover, I don't want to take the chance on the darn thing leaking when zipping it back together. If the fill plug was in a better place I'd try to use my vacuum pump to suck it out warm & just refill. Grrr.
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If you’re rarely towing, why use the SVG?
Same. Use Amsoil SVG 75/90 in both the Canyon & Bronco.
The number of QT in the differential is only a few, changed not very often so the extra cost is negligible.
My feeling is if you go to the hassle of getting Amsoil products why not get the best ones.
I buy their SVG gear oil and their best ATF.
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I see.
I hadn’t been under the rear end of the Chevy in a year or so. Somehow I don’t think differential lubricant is the likely failure point of this vehicle.
JHZR2
Staff member
This is reality. They aren’t a complex item. Though some can get whiny I suspect due to insufficient maintenance.Most differentials never get their oil changed and go to the junkyard on their factory fill
That’s just it. It’s not motor oil, no exposure to fuel or combustion byproducts, or severely oxidizing conditions. It can oxidize, can gain moisture, can disperse metal particulates, etc.
Old high mileage doffs will get a nice coating of gunk on the outsides. This likely also affects heat transfer. Here’s a Dodge Ram Dana 70 with 445k.
I'd guess the lack of gear oil will be the COD of that rear. The rear pumpkin cover is probably rusted paper thin with pinholes.
Patman
Staff member
They aren’t advertising them this way but I bet you there are a lot of very high mileage cars out there that have never had a rear end fluid change. It just doesn’t see the same level as stress as a transmission or engine and doesn’t get the contamination.
I never changed the rear end fluid in my 98 Corvette and I had 215,000 km on it when I sold it.
I wasn’t planning on doing the rear end fluid in my current Corvette for a while but I had some warranty work done on it at 71,000 km and they changed the rear end fluid during that work. I likely won’t change it again until maybe 200 to 250,000 km.
This thread reminded me thinking about gear oil so I did a suction change on the front axle of our Expedition. Pulling the cover is a big job on that rig as you have to disconnect a bunch of suspension components and shift the axle back to make room.
It was at least 60k since the last time it was done, but the stuff I pumped out was not much darker than the stuff I pumped in which makes sense as 4WD is rarely needed around here.
It was at least 60k since the last time it was done, but the stuff I pumped out was not much darker than the stuff I pumped in which makes sense as 4WD is rarely needed around here.
I think those spring mounts will probably snap off first. This truck gets driven mostly off-road now.
I agree the lubrication of the differential is much less demanding than motor oil on an engine but I have seen the gear oil come out pretty black looking from the rear differential case.
JHZR2
Staff member
Absolutely. And murky from the front one if it doesn’t get hot enough often enough.
A little off topic, reminds me of my dad's 05 blazer. Last year for Canadian model. It sat in the garage for 7 years. (2011) Then I needed to borrow it since insurance wrote off my wife's 2013 RAV4(in 2018) Only had 1 vehicle at that time. The pumpkin diff looked so rusted I was afraid to remove the bolts for fear of snapping bolts. IIRC the diff fluid hasn't been changed at all. It sits at 168k kms. Love that blazer, always started. Still in his garage unwilling to sell it. If I recall there's no drain, you had to remove the cover
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Yes. I have changed my Tacoma diff fluid 2x in 27k mi. But I go off road.
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