Andrew S: When removing the diff cover, it makes it easier to remove the bottom 3
bolts first, then get a flat head screwdriver and slightly pry the bottom
apart to let the fluid drip out. That way you don't get fluid coming down
the screwdriver and onto your hand.
maconsumner: Good teach!!!!! May I add, I used super fine steel wool to clean off the
mating surfaces before cleaning out the housing.
Giorgio Brembilla: what a nice explanation, thank you
BLAIJ009: Other than gear lube, what could you use in order to clean other
contaminants out? I don't think you want to use brake cleaner. :)
unclematt3: Great video. Thank you!
jaime perez: need aditive or not?
Miguel Marrero: thanks your video was very helpful. God bless you
StormTecify: Amsoil isnt the only Synthetic oil maker! Ford recommends Mastercraft
swikil: Hi John, Is it necessary to use "lube slip" when using 75w 140?
Octavio Zarco: whats the torque ...?
mago kim: Five stars ;)
Richard Bryan: Great video.
jon jo: my dad has a 2001 f-150 4.6. would it be pretty much the exact same
procedure? I know hes NEVER changed the rear diff oil ever and his truck
has 125 K I beleave.. Hope to hear from you soon
Tom Cook: I never use a gasket masker I just buy the gasket and place a dap of grease
in few spots to hold the gasket in place save time and money spent on
permatex ..torch the bolts to the required specks no leeks from water pumps
to differential cover..
Christian Richter: Good video, about to do it for the first time on my truck that year, just
got it so I'm worried about it never being done. Thanks, the instructions
in the shop book only go so far.
Fermin Garcia: Have you dont any for the front tranfercase bro I have the fx4
robert crozier: do you have any for the '04 f150's? my father said you need another
additive for the diff fluid. and an 04 f150 4.6L would be nice to see
done, dont want to pay $500 for someone else to do it.
FMXRIDER100: Best video online for doing a differential change!
Jon Olson: Thanks for the note. It's just the way I was taught.
Jon Olson: The 30,000 mile interval number came from approximating wear/tear values
through research. Typical gear oil will last 50,000 miles under normal
conditions. However, under severe conditions (heavy towing, etc) it may
last as little as 15,000 to 20,000 miles. Amsoil Severe Gear Oil will last
for 100,000 miles of normal service and 50,000 miles of severe service. As
far as synthetics...not all synthetics are manufactured with the same
standards of quality.
Jon Olson: Correct. There are many companies that sell synthetic gear oil. If you are
referring specifically to my comment at time code 7:00...it was my attempt
at a joke. If you are referring to the video as a whole...research studies
have demonstrated that Amsoil gear oils outperform all other synthetic gear
oil manufacturers. After doing extensive research and looking at many other
products/companies, I choose to use Amsoil.
shades2: Nice job.
trent young: I have an 03 f150 much like the one in this video, I can assure you the
axle lubricant is good for much longer the 30,000 miles under heavy loads.
I pull trailers more often them most people, mostly throughout the summer,
and i have 180000 miles on factory axle lube. I drive offroad often as
well. You can see my profile pic is my truck pulling a 25ft trailer that
weighs 6500lbs.. empty.. its for explosives (fireworks). I also pull my
camper, 16ft trailer covered and uncovered. food for thought..
zach berg: you want to let the permatex set up for a few minutes before assembling
trent young: i have the same axle as you but with the 4.6L same transmission i believe.
and i know why you havent changed out the spark pluggs yet, it took me 8
hours to get the factory ones out and replaced! be careful with the cheap
7mm bolt heads on the coil packs. half of mine stripped and i ended up
braking cylinder 7s coil pack to get the bolt off. i replaced them all with
grade 8 100 head bolts. preparing for the future lol.
Jon Olson: For the year prior to this service, I averaged 11.6 mpg (in town driving).
I replaced the front differential fluid, rear differential fluid, transfer
case fluid, and transmission fluid at the same time (see my other videos).
I then averaged 12.3 mpg (in town) over the succeeding 5 months. It is an
increase of 0.7 mpg, but when calculated out over 1 year it equates to a
savings of about an entire tank of gas. Plus I have the peace of mind
knowing that my engine is protected with Amsoil.
Jon Olson: The differential fluid does not lubricate the wheel bearings. You would
want to use Synthetic Multi-Purpose Grease NLGI #2 to grease the wheel
bearings. I have added a link in the video description above.
elwiso92: chevybio229 its probably a leak I had the same on my 93 and it went away
after I changed the oil and out the new gasket in.
Jon Olson: Thanks for the input. I agree that I should have been wearing gloves.
Automotive fluids are filled with contaminants that are very hazardous.
Angel Lopez: A+ thanks.
javier carreon negrete: Hello, I'd also like to know the answer to this question... many people say
that the wheel bearings are lubricated with the diferential oil but idk if
that's true... I changed the front wheel bearings of my vehicle (one was
damaged and decided to change both) and I want to know this before I decide
to change the rear bearings (just for maintenance, don't think they need to
Jon Olson: I agree that my mpg is in question. I have a feeling that my spark plugs
are the factory original and may be a contributing factor, but have not yet
had the time (or desire) to tackle that project. I am running 265/70R17,
4R70W Automatic, 9.75 axle with 3.55 Non-LS and 5.4L Engine.
Jordan Hooper: Hello! I own a '99 F-150 and went to do this very Job. I went to buy the
silicon gasket maker, but they sold me a cork gasket and swore it was
factory? I knew better, but I tried it. 3 weeks later, I'm doing the job
again. Don't let auto parts stores tell you what to put on your vehicle..
It's yours, do what you want. Lol thanks for the vid! Going to start on
Jon Olson: It is always good practice to check all of your fluids regularly, this
includes fluids which the manufacturer claims are good for "life".
Automotive fluids and lubricants do not last forever and Ford does not
provide manufacturer specifications on what they determine is the "life" of
the vehicle or the "life" of the lubricant. As the video demonstrated, this
fluid had about 100,000 miles on it and there were significant amounts of
metallic particles floating about. No amount of this is good.
Michael Page: Good job Jon, thank you for the info.
moquiti: Another thing to check before applying the Permatex is to check the
flatness of the cover along the gasket mating surface, or rim. The metal
may be dimpled somewhat around each bolt hole, caused by gasket
compression. This can be flattened with careful use of a hammer and a small
bit of thick steel plate, working from the inside side of the cover. The
surface must be supported on the back side (cover outside) by a solid
surface, preferably a flat steel surface of some kind.
stchman: Amsoil is not the only company that sells synthetic gear oil.
moquiti: A narrow putty knife or paint scraper works better than a flat screwdriver
for loosening the cover without damaging the mating surfaces.
youngin229: What if the outside of the rear differential looks wet when it haven't been
moquiti: Does the differential fluid lubricate the wheel bearings, or is the axle
tube sealed off at the differential housing? (If it is open, additional oil
can be drained by tilting the axle one side at a time.)
javier carreon negrete: I want to know if it's really necessary to change the diferential oil, the
ford owner's manual states that it's designed to last the lifetime of the
vehicle and only recommends a change if the diferential has been immersed
in water. Thanks people.
fordwindsor351: you do not have to do as you said when taking the bolts out, only when
Jon Olson: I prefer the silicone as it conforms to pretty much any irregularity in the
mating surfaces. However, for this fix, the manufacturer recommended
reusing the gasket if it is in good condition so I decided to go this
Adilson DeSouza: how nice video?! congrats Jon. Easy to watch. :)
Jon Olson: The main problem is that Ford does not state what is meant by "lifetime".
The lifetime of the vehicle?...the lifetime of the fluid?...the lifetime of
the differential?...Many times when a system fails (ie. the differential),
the manufacturer will say, "Welp...it has exceeded it's lifetime, and needs
replaced". No fluid will last forever and the more debris/metal particles
that get in the fluid, the shorter the life of the system.
javier carreon negrete: Thanks Jon, another thing... the owner's manual says it takes like 3.19
liters of oil (little more than 3 quarters of galon) and also says some
antifriction aditive ounces are required (dont remember the motorcraft part
number). The oil is expensive here, I'm from Mexico so I will have to spend
more than 100 USD for a galon. You think it's ok if I just replace the oil
and forget about the aditive? Thanks in advance. [sorry about my english,
not my main language]
Jon Olson: Shaun, thanks for the question. Ford does call for a friction modifier when
changing differential fluid with conventional differential fluid, however,
AMSOIL Severe Gear Lubes contain friction modifier, so no added product is
MrPew17: They say that it doesn't need to be changed, however if it is leaking
(which they do), then you should drain it and replace the gasket.
Jon Olson: If you are replacing the oil with Amsoil Severe Gear (see link in video
description), all the required additives are already in the Gear Lube Oil.
I am not sure if conventional manufacturers put it in or not.
moneygeewtee: Great video/ Thanks for taking the time Jon.
EMT: Thanks! They sometimes skip corners and take the easy way. If they ever did that, I suggest you consult with a paralegal or lawyer. This way they won't be able to cheat you.