Oils & Oil Additives, what's good, what works?

Discuss technical aspects of your 4WD with other owners, and share your opinions
mydmax
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Re: Oil additives - AW10 Antiwear

Unread post by mydmax » March 6th, 2013, 8:24 am

underseige
For most people to supply aftermarket gears means they have to make a profit and if $500 was cut off the bill I would be horrified to know what they would charge full price.
However, because they are made by "someone" who won't have state of the art helical gear cutting machines worth hundreds of thousands of $$$$ or even millions, you will get gear which will do the job but are not as high tech or even straight cut gears and not helical cut ones.
If straight cut they will scream while they deliver the power. Similar to all the Doodler Comdoooooor drivers who want straight cut gears in their engine so it makes noise and broadcasts to everyone how cool or stupid they are. depending on viewpoint of course.
I'm not inferring you are stupid, they did theirs by choice, you just have to cop the noise of poor tech gears.
They might last a long time and do the job well. They are just not quiet as quality gears are.

Fitting these gears by a "pro" as you put it has noting to do with having or eliminating the noise, it is inherent in the design of the gears cut. Effectively the teeth don't gently engage the drive , they suddenly jump from tooth to tooth and being this way they are also prone to breakage with sudden high torque loadings.

The noise, life expectancy and the ability to transfer high torque is the reason why diff gears are not straight cut bevel gears but offset complex design hypoid gears which is a very smart intelligent mathematical adaption of trying to have helical cut bevel gears.

Yours is just a transfer case so in the suppliers eyes, cheap will do for you. May not be cheap to buy though.
gears cutting is a science and the people who make aftermarket gears may not be good at science.

mydmax

whizzo
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Re: Oil additives - AW10 Antiwear

Unread post by whizzo » March 6th, 2013, 8:58 am

Even if they do have the facility to do proper helical cuts,,because of the steeper ratios involved they may not be able to cut the gear in as quiet a fashon...or it may requere a lot more smarts to do so...even then still not as quiet

Back in the day I drove a mates escort rally car that had a QUALF gearbox fitted, this was what all the top teams where running and was straight cut gears...very noisy even in 4th.

cheers

Indy Hepburn
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Oil additives?

Unread post by Indy Hepburn » April 4th, 2014, 10:08 pm

Hi guys does anyone here use oil additives? to help motors last for ages..

My bro in law said his falcon had something added to the oil..was still going at 700,000km..not using any oil either..of course if you look after a car it helps it last..but would love to know what can extend engine life :thumb:

dhc4ever
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Re: Oils & Oil Additives, what's good, what works?

Unread post by dhc4ever » April 5th, 2014, 6:20 am

Indy,
Just use a good quality oil and change it and the filters when specified.
There is no magic money saving , one drop and you engine lasts forever additives.
Cheers

Tharce
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Re: Oils & Oil Additives, what's good, what works?

Unread post by Tharce » July 30th, 2018, 10:53 pm

I could not resist...
The nano technology is a benefit in so far as it is chemically inert and unlike the historic friction modifiers of old that used chemistry (Zinc and Sulphur) and temperature to activate, the new types work in much the same way as older solid suspensions of EP additive by coating onto the surface to create a lower friction layer. Typically oils would have a fatty acids to reduce friction on start up, whilst AW or Anti-Wear (ZDDP or Zinc DialkylDithioPhosphate) would be used for metal-to-metal contact at higher contact temperatures, and for extreme loading and very high contact temperatures, EP in the form of Sulphur-Phosphor (which you can smell the odour of easily) was used. But EP oils can attack Copper and copper based alloys so solids of Molybdenum DiSulphide, Graphite or even PTFE(Teflon) are used in alternative cases in gear oils.

Engines historically used AW with no need for EP, but owing to the restriction on metals because of the Cat exhaust and the environmental pressure, Zinc and Sulphur have been reduced to a large degree in oils, although ZDDP is still partly there to counter corrosion and oil oxidation. Engine oils, particularly diesel, also have alkaline detergent packs that help neutralise Sulphuric acid formation in the sump from water and Sulphur in the fuel mixing following fuel dilution. This is more a concern on diesels, though.

Of course, on an engine this is only necessary during a start as normally the majority of the components are separated by a film of oil so the base oil quality is equally important in ensuring that the most susceptible parts such as the soft bearing shells are not in contact with the opposing component. No additive will improve the film strength of the oil as such except increase it's viscosity and then you start suffering efficiency losses owing to the increased drag of a thicker oil. Synthetic base oils have a greater film strength than mineral and semi-synthetic oils at an equivalent viscosity grade so can maintain the film despite being thinner.

Consequently a high quality oil is actually a compromise that must allow the additives to do their job without interfering with each other. Adding chemicals will upset that balance but likewise adding physically inert suspensions can lead to these being trapped in the filter or worse collecting in fine oil ways and choking the flow. There is absolutely no need for friction modifiers in an engine once it is running.

Any demonstrations of the chemical type of best oil additives should be taken with a pinch of salt. The classic demonstration using a Timken OK load test rig with lever is fundamentally flawed. The demonstration shows that with standard engine oil the lever can manage three weights before the test rig grinds to a halt and scarring occurs on the test piece. With the chemically active substances, what in effect happens is the metal softens to reduce friction and thus a much greater number of weights can be added, but the fact that scarring has disappeared is due to the metal softening and flowing with the result that the surface now appears smooth. What has happened though is that the profile has changed and this would lead to improper clearance and lots of backlash noise on a gear set. In addition, there is no where on an engine that would encounter such a level of metal-to-metal contact loading so there is no need otherwise the oil companies would have added something to the oil to protect the engine.

Finally, with any f these additives, ask the supplier if they have an independent research study to back up the claim, and secondly if they have an MSDS. Some of the additives are chlorinated material (hair shampoo and milk can achieve the same results!) but the chlorinated material on mixing with moisture in the sump (condensation etc.) can produce PCBs which are damaging to the nervous system.

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