Ok. I respect you have an opinion and a lot of experience. I think you said the viscosity wouldn't make a difference in the rear diff ... Between 2 different viscosities. Me, I'd ensure the manufacturer specified viscosity is in there.
Makuloco also advised very frequent changes of every fluid in the Expy like 30k for transmission I think and 3k for oil. Do you agree with those frequencies and changing the brake fluid? I think he is advising the most frequent possible fluid changes for everything. Front rear diff transfer case etc. I expected him to advise changing wiper fluid and battery acid next.
My main Experience with Expys is 3 of them with 5.4 engines following manufacturer reccs or s bit sooner. Like I changed my plugs at 80k.
I gotta admit. I'm not a big fan of Conspiracy Theories so a red flag is raised when I think I'm hearing one. So when someone says the auto manufacturers are out to get you I see a red flag.
But there is NO question you know more about engines and auto repair than I do.
I only have a lot of experience with certain engines. There are so many cars out there that I've never even open the hood on it.
Also, just because a guy is good at one doesn't mean you should value his opinion on everything. I used to have frequent contact with a GM Master Tech who knew everything there was to know about General Motors Vehicles. He could take any of the Transmissions apart and fully rebuild them etc and that's especially in the transmission world.
He called me one day and I literally laughed at him when he asked me a question about a Ford Taurus! He's like, dude I don't know anything about Ford's I don't work on them and I've never owned one.
So some people are out there giving blanket advice about things that might not be true.
A safe bet is to follow the manufacturer recommendations or do things a little bit earlier because most cars are lasting a long time now anyway so you don't really have to maximize every mile you can get out of one. Few new car purchasers keep the vehicle until the engine life is is used up at over 200,000 miles.
Some of us only buy old cars though so we do look to maximize things since from the start we have a shorter possibility of lifespan.
Some people put way too much thought into it like being picky about what brand of everything they put on their car or what brand of oil. There are still people that won't use certain brands of oils or have their preference. In reality, it's more about the viscosity and the frequency of oil changes and it's not going to affect the life of your engine regardless of which brand you use.
The thing about the differential fluid is that there's only two this guy sees really readily available so either thing you grab is going to be okay. The next part of the problem is that Ford started out selling vehicles and recommending a certain viscosity but then later on changing their mind when these vehicles are 8 or 10 years old and then saying to use the other viscosity in the new ones and even all the old ones.
This was not because they found out they were having a lot of differential failures in the first 10 years so they switched, more than likely it was just because they only want to carry one type of gear lube for their dealers and it just makes it uniform and simpler.
Also, most people will tell you that the 75-140 full synthetic is the best gear lube to put in any with differential because it is better band The Cars That only spec for the 80w 90 but there are people that will tell you and there have been test confirm but in certain applications the ring and pinion and metal parts inside actually get hotter with the synthetic oil than they do with the plain old 80w 90 that we have been using for a hundred years in cars.
So this is where you really can't believe either side to fully. Do you have to go with your own personal experience unless you know someone very closely who has personal experience or cars at your job or whatever. Usually there is no real experience because hardly anyone has ever had a differential failure due to improper Lube. Any damage that has ever occurred to one has been contaminated Lube or not enough Lube.
So my parsley joke full comment was grabbing a bottle of gear lube it looks like gear lube and it's really all going to work the same. You could also pour straight Lucas in there which has the same shape bottle and it even says that for noisy or warm ones you can use it at 100%. I wouldn't do it to a good one but I don't think it would damage one.
I have not washed all his videos or recommendations but from what you said it sounds like he is a little overzealous on some things.
Not on oil changes though. We have this back-and-forth thing. For years people didn't change their oil very often and then when all the Quick Lube oil change places came out pioneered by Jiffy Lube I think oh, I can still sing the song, they convinced the American people that it was necessary to change your oil every 3 months or 3000 miles. We find out now that that was Overkill and that the 5 to 7500 manufacturer recommendations for normal service was just fine. Now however with VVT we are finding that the high end of manufacturer recommendations cannot be the best thing overall.
You need to increase the oil change frequency and or use a fully synthetic oil to keep the all clean and their screens from getting all clogged up and causing you problems with the solenoids.
Flushing your coolant really doesn't do a whole lot. It makes people feel better to look in the cap and see nice pretty green fluid or on the newer things the other colors but I have owned vehicles that were 13 to 15 years old that had never had the fluid changed in their lives and you can't drive them on a thousand mile trip and they wouldn't overheat a bit.
Nice cars most cars it will make little difference whether you changed and flush the fluid in the radiator and cooling system every 3 years or every 10 years. It just won't make a difference .
now there are some cars that have problems to start with where it will slow down your frequency of problems. So this is the conundrum. now there are some cars that have problems to start with Where it will slow down your frequency of problems. So this is the conundrum. If you have a car with spurious electrical current getting in your cooling system it will rot away your heater core faster. If you change your radiator fluid and keep high-quality coolant like Preston in there every two to 3 years you should get a few more years out of it. But having said that, most heater cores on most cars go 15 to 20 years before they start to leak. Some never leak.
The 95 to 97 Town Cars had a fairly wimpy radiator and if you didn't flush the coolant and four to five years that would be enough restriction or coating inside the radiator that it would overheat.
if you flushed it regularly and use one of the cleaners you would probably get another three or four years before the radiator need to be replaced.
I had one that did it consistently every four years. I did not flush it after the first radiator went in but it had fresh coolant. Exactly four years later it started overheating again so I warranted the lifetime warranty radiator and put new coolant in it again.
Flushing power steering fluid is a waste of time on most cars you would be better off to add one of the higher-end additive and leave it be. Most people really start thinking about flushing until they have stiffness or a problem and a flush rarely solve that issue.
Flushing your brake fluid is an absolute waste of time and money but it makes people feel better.
I can't tell you how many 15 to 20 year old plus cars I have had that have never had the brake fluid flushed. Over the years when you do brake jobs and bleed them a couple of pumps you do manage to flush a little bit through but I mean they've never had an entire master cylinder flush through or empty cleaned out and flush through the lines with brand-new fluid. Your calipers well stick on their sliders, Pistons will Rust away or the phenolic ones will crack or things will just start leaking way before you'll ever have an issue in your brake system because you didn't flush your fluid.
The theory of brake lines rusting from the inside is an old wives tale. Unless you left a quart of brake fluid out with the lid off and it true in a lot of moisture which I think you would actually have to pour water into it to get enough moisture, and then poured it into your brake system, you are not going to get rust from the inside out. I have done more brake lines in my life than most other human beings because I have maintained a fleet of town cars and limousines for myself and two other people for the past 25 years. Every limo ever built will have to have brake lines and typically fuel lines replaced before the vehicle is sold off into private use or goes to the scrap yard.
The last Town Car stretch I replace brake lines on needed 34 ft to do both rear ones. The rear are the only ones ever rust out as the fronts are still in their Factory configuration and they are stainless. So when I do a brake line it's a lot of brake line.
I used to believe or at least thought it was possible that they rusted from the inside but I started checking them. Now this only applies in this salt States they might make it long enough to rust from the inside out in a nice dry no salt environment but I have never, ever remove a rusted out leaking brake line that when you inspect three or four different areas on the line and cut it in half with a tubing cutter ... the outside is flaked off rust has holes all in it and is either leaking or ready to leak at any given moment but as you get to the inside you hit nice shiny white clean Steel.
We have to go with whatever works for us and what has worked but sometimes will never actually know if we've always done something one way and had good results it doesn't mean it's the only way. Other people hardly do anything or do these people be different I get the same results or even better than we do.
All I know is that I don't lie or make up shit. That's why I get frustrated and double down when somebody wants to contradict me on a forum. If I tell you that's the way it's been for me repeatedly over and over you can take it to the bank at that is exactly how it occurred. Of course, this does not guarantee any results for you or in your neck of the woods but some things are pretty consistent.
That's why I don't care about other people talking about facts or spewing statistics. If they don't match what I have experienced in the past four decades of working on cars then they mean nothing to me and they had nothing to do with my decision making future process.
