Better than nothing rear differential fluid change

GON

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718
Location
SLC, UT
Second owner of a 2002 F350 V10. 180k miles. Original owner appeared to be very frugal with maintenance.

Moving across country and towing about 10k. Went to change the rear differential fluid, noticed it had been done before- but likely not in a while. The differential cover and screws were oozing gasket. I was afraid to take the cover off, as I have a trailer to load and don't need a one hour job turning into a half day job. I purchased a new differential cover and a pre made gasket.

Decided to simply siphon the old fluid out from the fill hole. This took about 16 hours, as the fluid was cold when I started, and we are having cold nights in Utah. The capacity is about 3.3 quarts. I was able to siphon three quarts- more than I thought. I loaded the trailer and slept during the drain. This method is not for people in a hurry. Overnight at a minimum.

I did not jack up the truck, did this on the street in front of my driveway. Only tool required was a 3/8 ratchet that was it (along with the tube and the new fluid pump and drain pan).

One of the pics show the new fluid as a green color. That color change was due to the addition of limited slip supplement to the fluid.

Two tips- use a hard and smaller diameter tube. And make sure your place a heavy item near the end of the tube in the drain pan to keep the hose from lifting and disrupting the flow.

Not a perfect exchange, but much better than doing nothing.



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to the new fluid.
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GON

$50 Site Donor
Thread starter
Messages
718
Location
SLC, UT
A turkey baster is faster. I have a suction gun that would suck it out in about 10 min
Only a very small hard tube can get down to grab the rear differential fluid. The tube has to stay firm yet route around to the bottom of the differential. Turkey baster, mity vac, etc, likely not feasible without retrofitting the input tube. This method takes just a few minutes of actual work. When the tube is clear (and the pan filled with the old stuff), it is done. Takes a long, long time. But actual labor is under five minutes.
 
Messages
5,581
Location
Ohio
I don't have the patience to do it as you did but looks like a good job done that will prolong the life of your diffie.

I use my five dollar manual pump from Harbor Freight to extract and place the one quart jug's nozzle into the hole and squeeze in the new oil. Wouldn't work with the bottles you have but have used a large trigger oil gun to squirt in the new oil. Either way I am done in about an hour.
 
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8,786
Location
Champlain/Hudson Valley
I'd be interested to know details regarding STARTING the siphon action.
Did you fill the tube and cover the end with your thumb...or suck on the line?
Hey, if time wasn't important then why not?
Drive safely...you got what, 3 rounders ahead of you?
 
Messages
2,225
Location
socal
Since you already purchased a new cover and gasket, I would’ve just replaced it while draining fluid completely . But you’re correct, better than nothing
 

GON

$50 Site Donor
Thread starter
Messages
718
Location
SLC, UT
I'd be interested to know details regarding STARTING the siphon action.
Did you fill the tube and cover the end with your thumb...or suck on the line?
Hey, if time wasn't important then why not?
Drive safely...you got what, 3 rounders ahead of you?
Sucked on the line. Unlike siphoning gas as a kid for minibikes from a car getting a mouthful of gas, differential oil moves so slow you can see it coming and get the end of the tube into the drain pan with getting any oil in the mouth.
 

GON

$50 Site Donor
Thread starter
Messages
718
Location
SLC, UT
Since you already purchased a new cover and gasket, I would’ve just replaced it while draining fluid completely . But you’re correct, better than nothing
I was afraid it was going to get into a project cleaning off the gasket sealer from the prior change. Ever have one of those "good ideas" that turned into a big project? I was fearful of that.
 
Messages
105
Location
Vancouver, WA
Yeah, but ya gotta clean it...
Love my MityVac, but I have never cleaned it.

Well, cleaning Mityvac is some work. But it's much easier than pumping 3 qts of diff oil with small hand pump. And in this case, just fill the Mityvac with diff oil, waste a few ounce before filling the differential. I've cleaned Mityvac a few times prior to using it for diff & transfer case fluid. The darn small hand pumps I have are too slow and awkward to use lying down under the vehicle.
 
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Messages
1,386
Location
Pacific Northwest
The mitivac does make diff services a lot easier. You may not get every last drop out, but if you do it a little more often I figure you're still way ahead of the game.

Love my MityVac, but I have never cleaned it.

I've never used the mityvac to add fluid, either. Too much work to clean it. For differential filling, I snake a 3/8's inner diameter plastic tube up through the wheel well and down into the fill hole so I don't have to mess with pumps while laying on my back. The squirt cap on the bottle fits into the tube and lets you add the oil while standing up. Easy-peasy.

With the OP's rig with the Sterling axle, you can also pull the speed sensor to get access to fill or suction out the fluid. The fill plug on mine was rounded out and the speed sensor was a lot easier to deal with than welding nuts and such on the plug.
 
Messages
1,592
Location
UT
I only use my Mityvac for extraction. For fill, I've got a couple modified garden sprayers, a two gallon for transmission fluid and a one gallon for differential fluid. The right tools definitely make diff fluid changes a breeze.

Does the new diff cover that you bought have a drain plug? Frankly, it has always irritated me when a rear diff doesn't have a drain plug. Same with transmission pans.
 
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