Axle lube specifications

[michael loibl]

I’m reading thru my 2020 owners manual and came across something that suprised me in the fluid specifications.

The rear axle calls for 75w85 synthetic and the front calls for 75w140 synthetic.

rear drive primary I would have expected the opposite.

For example my old 2006 Explorer rear drive primary calls for 75w140 REAR and 75w90 Front

 

[DoraAExplorer]

did your old explorer have a lsd? You need to use the specific oil it calls for or it could make noise. No Explorers as I have been able to tell for 2020 on come with LSDs. They all use the drive modes to modulate braking to give a faux LSD response.

 

[michael loibl]

No my 2006 does not have LSD, I think that option went away in around 2004 when the fancy stability control became standard.

I just find it odd that the new one would call for the 75w140 in the front only, when the old one called for it in the rear only. Being both are rear drive primary.

 

[CDW6212R]

I would bet that is a misprint, you want the heavier gear oil in the primary diff.

BTW, buy the best gear oil, don't skimp on that critical fluid. I choose Amsoil, they make the best gear oil, and it's called Severe Gear. Theirs is better than the other top brands by a lot, and it costs less, about $14-$15 a quart. They make three viscosity's and I have some of each on hand most of the time.

 

[quickfix]

I would bet that is a misprint, you want the heavier gear oil in the primary diff.

BTW, buy the best gear oil, don't skimp on that critical fluid. I choose Amsoil, they make the best gear oil, and it's called Severe Gear. Theirs is better than the other top brands by a lot, and it costs less, about $14-$15 a quart. They make three viscosity's and I have some of each on hand most of the time.

I agree. It even calls it Rear Axle lubricant in the specs. Bet it's a carry over from the previous generation.

I've met bad technical order writers in the air force...and its contractors. Copy and paste without actually knowing what the changes were in the latest system/eguipment mods, leaflets and prototype kit. I was deeply involved in the flight test and evaluation of our four engine long range patrol aircraft's incremental update program. Decades are generally required to amend the aircraft operating instructions and tech orders/manuals due to faulty writing.

 

[CDW6212R]

Ditto. I have seen lots of errors in parts books and manuals. People notice the most when it's a part they are sold, which doesn't work and they go back to a store to figure it out. I like to believe what people tell me, rather than what's in a book. Nothing's perfect, but word of mouth knowledge is precious.

 

[DoraAExplorer]

What is the change interval for the rear diff? I know the spark plugs recommend changing every 60 thousand miles which is short for platinum plugs, IMO. However, with a turbo vehicle I would definetly follow that recommendation. You can go ahead and waste money on Amsoil, Royal Purple, and the like. A good 5w 30 synthetic is hard to beat for high viscosity turbo applications. I run Castrol GTX in my Subaru STI and it holds up great before that I ran Pennzoil. Good synthetic oil is all you need with regular 5-7 thousand mile oil changes you can not go wrong.

Modern synthetic oils are all about the same as long as they met the SN spec. If you get some perceived extra feel good protection from using those oils then by own means use them but I have been into vehicles all my life and went through those premium brand golden oil phases. They are waste of money. The rear diff is no difference and actually in that high temperature, high pressure environments regular dino or synth bends actually perform a little better than full on synthetics.

 

[CDW6212R]

Wow, wrong, and I'm surprised to see apparently someone who works on cars, to not know this.

Basic dino oil is a very poor choice for any turbo engine, and very bad for any modern engine that has critical clean oil needs like the Explorer 4.0 SOHC engine. All of those engines are very important to use the best engine oil possible, any less is why higher mileage vehicles use oil a lot, and rattle, and fail early etc.

Oil specs don't mean S**t when en engine is pushing the limits of all oils. The newer turbos and direct injection systems are taxing every oil made, and OEM is still calling for 7500+ mile intervals. That is a recipe for many engine issues, and they are being reported more and more. Many of those will be from using lesser quality oils, and/or going too long on the oil.

Spark plugs begin to be very hard to remove after 75k miles etc, and people keep liking the suggestion to run plugs for 100k etc. There are countless vehicles out there that have never had the plugs changed, the service intervals are making people believe it's not important to do them.

Gear oil is in one of the harshest environments, using cheap brands for that is just cheap and dumb. I always used the best which was available, and then some better brands came along. When it became easier to buy them, I've tried them and they are better. Amsoil is the best IMO, and Royal Purple is very good also, OEM Ford is not far behind. I would never use any off brand or non synthetic gear oil, unless it was an emergency. The long term(high mileage) damage caused by lesser fluids is not worth it, and much more expensive than what little extra Amsoil etc, costs.

 

[DoraAExplorer]

Wow, wrong, and I'm surprised to see apparently someone who works on cars, to not know this.

Basic dino oil is a very poor choice for any turbo engine, and very bad for any modern engine that has critical clean oil needs like the Explorer 4.0 SOHC engine. All of those engines are very important to use the best engine oil possible, any less is why higher mileage vehicles use oil a lot, and rattle, and fail early etc.

Oil specs don't mean S**t when en engine is pushing the limits of all oils. The newer turbos and direct injection systems are taxing every oil made, and OEM is still calling for 7500+ mile intervals. That is a recipe for many engine issues, and they are being reported more and more. Many of those will be from using lesser quality oils, and/or going too long on the oil.

Spark plugs begin to be very hard to remove after 75k miles etc, and people keep liking the suggestion to run plugs for 100k etc. There are countless vehicles out there that have never had the plugs changed, the service intervals are making people believe it's not important to do them.

Gear oil is in one of the harshest environments, using cheap brands for that is just cheap and dumb. I always used the best which was available, and then some better brands came along. When it became easier to buy them, I've tried them and they are better. Amsoil is the best IMO, and Royal Purple is very good also, OEM Ford is not far behind. I would never use any off brand or non synthetic gear oil, unless it was an emergency. The long term(high mileage) damage caused by lesser fluids is not worth it, and much more expensive than what little extra Amsoil etc, costs.

I was talking about the Dino and blends for the rear differentials and while I did not read all of your long post I assure you that dino and blends do work well in the rear differentials. Spend money on what you want and maintain your vehicles how you feel that you should but I am not wasting my money on Amsoil or Royal Purple. What motor oil have you ever seen that is purple?

I have the 3.5 liter Ecoboost HO motor in my F150 and while I run Motorcraft synthetic oil in it, the manual states to use the Motor-craft synthetic blend which can be used. I do only run premium fuels (93 Octane) and synthetic oils in all my turbo vehicles and always have. However Castrol GTX Edge and Pennzoil Platinum at 30 bucks a 5 quart jug is just as good and as effective at protection as your twice as much Amsoil, Motul, etc etc. Unless you are saying that they are off brands?

Valvoline synthetic or Durablend is good gear oil as well. Run what you want since it is your vehicle but the gear oils are a little different than motor oils and Valvoline makes a quality product as well. I once used Royal Purple high end super gear oil in a Nissan VLSD and it made noise. I switched to Valvoline Durablend gear oil and it was quite as could be. This was for the same viscosity so there was some friction modifiers in the Royal Purple gear oil that the VLSD did not like. Luqi Moly also makes a great gear oil. If you get some sort of added security from using expense premium oils then by all means continue to use them. However, as I stated IMO they are waste of money as modern oils from a quality supplier provide certified levels of manufacturer protections that meet all requirements.

 

[peterk9]

Wow, wrong, and I'm surprised to see apparently someone who works on cars, to not know this.

Basic dino oil is a very poor choice for any turbo engine, and very bad for any modern engine that has critical clean oil needs like the Explorer 4.0 SOHC engine. All of those engines are very important to use the best engine oil possible, any less is why higher mileage vehicles use oil a lot, and rattle, and fail early etc.
.............................................................................

All the Explorers built for Canada come with just the regular Super Premium Motor oil in them and it is also the recommended oil. All my vehicles had that oil put in by the dealer, even after I inquired about it. I did not ask them to change that.

Peter

 

[peterk9]

I’m reading thru my 2020 owners manual and came across something that suprised me in the fluid specifications.

The rear axle calls for 75w85 synthetic and the front calls for 75w140 synthetic.

rear drive primary I would have expected the opposite.

For example my old 2006 Explorer rear drive primary calls for 75w140 REAR and 75w90 Front

My Aviator Manual also shows the same thing. What I find odd is the front is described as Motorcraft® SAE 75W-140 Synthetic Rear Axle Lubricant(U.S.) Rear axle shows Motorcraft® SAE 75W-85 Premium Synthetic Hypoid Gear Lubricant(U.S.)

Peter

 

[DoraAExplorer]

My Aviator Manual also shows the same thing. What I find odd is the front is described as Motorcraft® SAE 75W-140 Synthetic Rear Axle Lubricant(U.S.) Rear axle shows Motorcraft® SAE 75W-85 Premium Synthetic Hypoid Gear Lubricant(U.S.)

Peter

You just hit it then the rear differential on the 6th gen Explorer/ Aviator is a Hypoid design and the gear oil selected with have to contain gear wear modifiers that are safe for that rear end. Even if you were to switch this out you would have to run a Hypoid safe gear oil that has these modifiers or it could make a awful noise like my Nissan VLSD did or better yet it could destroy the rear diff.

 

[CDW6212R]

All the Explorers built for Canada come with just the regular Super Premium Motor oil in them and it is also the recommended oil. All my vehicles had that oil put in by the dealer, even after I inquired about it. I did not ask them to change that.

Peter

All new vehicles should use regular oil in them, for break in of the engine. Synthetic oil is very bad for a brand new engine, it should only be used after a good break in period. It used to be wait until 3000 miles, and then 1000 miles was the point to wait for. I think a good 500 miles is enough given modern cylinder machining(honing) methods.

 

[quickfix]

All 100% of new vehicles must use regular oil in them, for break in of the engine. Synthetic oil is very bad for a brand new engine, it should only be used after a good break in period. It used to be wait until 3000 miles, and then 1000 miles was the point to wait for. I think a good 500 miles is enough given modern cylinder machining(honing) methods.

Here's a site with a list of cars that come factory filled with Mobil 1 Synthetic.

Why auto manufacturers use Mobil 1™ oil | Mobil™

Many auto manufacturers use Mobil 1™ motor oil as their original-equipment lubricant of their new cars. Learn which cars leave the factory filled with Mobil 1 motor oil.

www.mobil.com

That's just Mobil1. There's probably others, but it's late at night and time for bed.

 

[CDW6212R]

That is good, engine machining has come a long way. The point is still, synthetic oil is the best for all engines past a short new engine period of time, regardless of what it came with. That some do come with synthetic when new, that's great if the machining of the cylinders allows for proper break in of the piston rings.

 

[DoraAExplorer]

That is good, engine machining has come a long way. The point is still, synthetic oil is the best for all engines past a short new engine period of time, regardless of what it came with. That some do come with synthetic when new, that's great if the machining of the cylinders allows for proper break in of the piston rings.

I am not sure of Fords high end models such as the GT40, GT, or GT500 but their highest models including most Ford Performance models come filled with the synthetic blend. You have to ask for the full synthetic at the works package and it usually adds 30 bucks to it.

 

[KKRISKAL]

That is good, engine machining has come a long way. The point is still, synthetic oil is the best for all engines past a short new engine period of time, regardless of what it came with. That some do come with synthetic when new, that's great if the machining of the cylinders allows for proper break in of the piston rings.

I agree, several of the cars (including performance vehicles) I have owned have come with full synthetic oil from the factory and until few years back, even my V8 Camaro came with Mobil 1 full synthetic until GM got their own synthetic oil

 

[Mbrooks420]

Rings will seat absolutely fine on synthetics. This is a synthetic oil myth. Zero need for convention oil on a new motor.

 

[CDW6212R]

Rings will seat absolutely fine on synthetics. This is a synthetic oil myth. Zero need for convention oil on a new motor.

I like hearing that, I didn't know it had been discovered to be a myth. It's good to debunk myths, thank you.

 

[buzzard302]

I like hearing that, I didn't know it had been discovered to be a myth. It's good to debunk myths, thank you.

Another thing is these days most production engines are pre-run at the engine factory. This is to seat the rings and ensure no issues before installation. So some of the piston ring concerns are addressed before the engine goes into service anyways. The manufacturers feel confident to put synthetic in as a factory fill.