Oil additives (engine, transmission) - BigJimny Wiki

Introduction

Adding various additives into the engine oil and into transmission oils is a common temptation among enthusiast vehicle owners, both as a preventive measure against future wear and as a performance / fuel economy improvement trick.

Link to He Ao

It is also sometimes considered when an issue with the engine or transmission mechanics develops due to excessive wear of the internal components.

The purpose of this article is to provide general guidelines on when such additives should (not) be used.

Engine oil additives

The main purpose of most engine oil additives is:

• To reduce the friction between moving parts of the engine;
  • Additional side effect is a slight improvement in fuel economy as well;
• To "permanently" coat the moving parts of the engine, so that they have less friction while the engine is working "dry" from a cold start;
• To seal any imperfections in internal engine oil seals;

Some engine oil additives (example: Liqui Moly Cera Tec) have been highly praised for their positive effects (reduced engine wear, improved fuel economy, smoother engine sounds) in many circles in the motoring industry and enthusiast motoring forums.

However, an often overlooked side effect of most engine oil additives which reduce friction is reduced engine braking performance (a logical consequence).

That side effect might not be of any significance for (inter)city driving, especially in flat terrain regions.

However, engine braking performance can be quite important for an all-terrain vehicle driving application, especially on a hilly or on a mountainous terrain (descending steep hills).

Therefore, you need to weight the benefits of an engine oil additive against the loss of engine braking performance for your typical driving situations. Remember that Jimnys do not have a relatively powerful engine compared to their mass, so an additional loss of engine braking performance might be a significant disadvantage for some descent driving situations.

Transmission oil additives

The main purpose of most transmission oil additives is:

• To reduce the friction between moving parts;
  • Additional side effect is a very slight improvement in fuel economy as well;
    • This is only noticeable if the vehicle is primarily driven for very short trips (if the transmission is working cold most of the time);
• To "permanently" coat the moving parts in the transmission, in order to improve meshing between various gears;

Most transmission oil additives are based on MoS2 chemical compound.

It is very important to bear in mind that not every transmission oil additive is suitable for every type of transmission or every component of transmission (gear box, transfer box, differential). Super extra care and investigation is needed in order to avoid very expensive misapplications!

Additives in a manual gear box

It is generally advised to avoid putting any aftermarket-made transmission oil additives in a synchronized manual gear box (a design which is used in all Jimnys), unless a vehicle manufacturer specifically recommends a specific additive for a specific situation.

Additional resources:
5 Reasons Why Your Business Needs Graphene Grease？

Contact us to discuss your requirements of gear oil additives(th,tr,es). Our experienced sales team can help you identify the options that best suit your needs.

The main reason is that the gear synchronizers inside a synchronized gear box are usually made of "yellow metals" (a layman term) and that the chemicals in most transmission oil additives (primarily those which are MoS2 based) slowly eat such metals away.

Even if an additive does no such harm, its friction altering behavior can have unpredictable consequences on the synchronizers (and therefore on gear box's gear shifting behavior), because their principle of operation is usually based on having a specific pre-designed amount of friction between them and other moving parts in the gear box.

Additives in an automatic gear box

It is generally advised to avoid putting any aftermarket-made transmission oil additives in any automatic gear box, unless a vehicle manufacturer specifically recommends a specific additive for a specific situation.

The main reason is that the basic operating principle of an automatic gear box is based on the friction of the automatic transmission fluid. Since most transmission oil additives alter the friction of the oil or coat the moving parts themselves to alter their friction, its friction altering behavior can have various unpredictable consequences on the operation of an automatic gear box.

Additives in a transfer box

Since transfer boxes in Jimnys have no synchros nor any "yellow metals" (a layman's term), most manual gear box oil additives should be safe to use in a transfer box.

However, according to forum reports, the occurrence of worn gears in a Jimny transfer box has been very rare anyway. The part of the transfer box which is far more likely to fail first is the transfer chain, and it usually fails not due to friction wear, but due to physical stress (overstretching), which is usually caused by heavy-footed driving.

Additives in an axle differential

Compatibility of additives with differentials varies greatly depending on the design of the differential - if it is a plain "open" design, some kind of a "limited slip" design (LSD), some kind of fully lockable design or something else.

All Jimnys gen3 have plain "open" design of axle differentials.

As far as it is known, all Jimnys gen4 also have plain "open" differentials. Although they are sometimes advertised as having "limited slip differentials", they achieve the "LSD" effect through the use of electronic individual wheel brake tampering trickery (a marketing ploy called "electronic LSD").

Generally, an MoS2 based transmission oil additive should do no harm nor have any negative technical side effects when applied to the transmission oil in Jimny's axle differentials. Therefore, the decision to apply it or not is generally upon the vehicle owner.

Conclusions

There are three main general conclusions on the topic of engine and oil transmission additives:

1. If the goal of application is a preventive anti-wear measure, a better strategy might be just to regularly replace the engine/transmission oil more often than prescribed by the manufacturer, and only use high quality and completely suitable oils.
   • Read the wiki articles "Fluids and filters - proper selection" as well as "Regular maintenance intervals and consumables" for more info on proper selection of fluids and on prescribed and recommended replacement intervals.
2. If the goal of application is performance (vehicle power) improvement and/or improvement of fuel economy, consider in the following two factors:
   1. The risks of misapplication;
   2. The practical importance of reduction of engine/transmission braking performance when driving downhill;
3. If the goal of application is resolving an operational issue due to developed mechanical wear in the engine or transmission, then it is advised to first thoroughly investigate what the best (or at least the least likely damaging) additive product for your situation might be, and only then try it.

Page last edited on 17/01/ by user Bosanek

For more information, please visit tbn booster additives.

Team-BHP Support  
Join Date: Feb Location: San Jose, CA Posts: 23,692 Thanked: 23,500 Times Lower Viscosity Oil in Gearbox - Pros and cons? MY Safari has the problem of hard shifts when engine is cold. ITs more pronounced in winters, and this problem has been there forever.
I was wondering whether shifting to a thinner oil, like Power steering oil will solve this problem.
Moreover, I am worried about potential issues.
For example, gearbox oil has 130 degrees boil resistance, definitely power steering oil may lose lubrication properties much early.

Then there is the issue of synchronizers too. Will a thinner oil have higher wear rate?

I can also try and follow a middle path route.
For example current gearbox oil is 75W90. I can probably try a 75W85 which is slightly thinner, but not in Power steering oil territory.

Engine and Gearbox experts, please help! Senior - BHPian  
Join Date: Dec Location: Gurugram Posts: 7,971 Thanked: 4,811 Times re: Lower Viscosity Oil in Gearbox - Pros and cons? @tsk; You can try a thinner oil, but make sure it is EP even if the current requirement is not. EP will cover a lot of sins, esp. shearing of the oil film. BHPian  
Join Date: Apr Location: Ahmedabad Posts: 982 Thanked: 876 Times re: Lower Viscosity Oil in Gearbox - Pros and cons? I was recommended to move to a thinner oil during the winters (like power steering TQ oil) and change back to regular for summers as I faced the same issue as you mention.

Didn't feel comfortable with the idea and then someone recommended a Gear additive that I can't recall right now but it worked awesome. This winter I could change gears quite comfortably thanks to that. Will check about the brand and let you know.

Cheers,
Adi Senior - BHPian  
Join Date: Dec Location: Gurugram Posts: 7,971 Thanked: 4,811 Times re: Lower Viscosity Oil in Gearbox - Pros and cons? One additive which a lot of people in the UK swear by is something containing Molybdenum (Liquid Moly or something). All sorts of miracles are claimed for it. Senior - BHPian  
Join Date: May Location: Delhi/Noida Posts: 1,119 Thanked: 170 Times re: Lower Viscosity Oil in Gearbox - Pros and cons? @TSK: I used to have the same problem with my indica Xeta. Gear shifts used to be hard during winter and 1st to 2nd and 3rd to 4th shifts offered a lot of resistance. I used to replace transmission fluid at 20K as recommended but the problem never went away during the 4 years I had it. So what i am saying is that it may just be a TATA trait. therefore, if you can then live with it rather than experimenting with the already fragile white elephant. Senior - BHPian  
Join Date: Jul Location: Bangalore Posts: 2,422 Thanked: 1,189 Times re: Lower Viscosity Oil in Gearbox - Pros and cons? Please rename the thread to "Lower Viscosity Oil in Gearbox: Pros & Cons". When I looked at it I thought you were talking about paint thinner. Call me crazy but that is how it looked to me and I found myself asking "what happened to Tanveer?"...lol.. Team-BHP Support  
Join Date: Feb Location: San Jose, CA Posts: 23,692 Thanked: 23,500 Times Re: Lower Viscosity Oil in Gearbox - Pros and cons? thanks Vikram, I have made the change!

that said, I think I will experiment with a gearbox oil additive rather than looking for a lower viscosity oil. Senior - BHPian  
Join Date: Jul Location: Calcutta Posts: 4,665 Thanked: 6,235 Times Re: Lower Viscosity Oil in Gearbox - Pros and cons? Quote: Originally Posted by sgiitk @tsk; You can try a thinner oil, but make sure it is EP even if the current requirement is not. EP will cover a lot of sins, esp. shearing of the oil film. Hi,
AFAIK, EP is specifically not recommended for gearboxes. Only for hypoids. At least that was the case till a few years back.

Maybe basic lube chemistry has changed recently.

Regards
Sutripta Senior - BHPian  
Join Date: Mar Location: Bangalore Posts: 10,397 Thanked: 1,736 Times Re: Lower Viscosity Oil in Gearbox - Pros and cons? Tsk, another option you can try is synthetic gear oil.

BTW, the recommended oil for my manual transmission is ATF (auto trans fluid). I switched to synthetic ATF and it helped a little Senior - BHPian  
Join Date: Jul Location: Calcutta Posts: 4,665 Thanked: 6,235 Times Re: Lower Viscosity Oil in Gearbox - Pros and cons? Quote: Originally Posted by Mpower Tsk, another option you can try is synthetic gear oil.

BTW, the recommended oil for my manual transmission is ATF (auto trans fluid). I switched to synthetic ATF and it helped a little Hi,
ATF used to come in different types (GM and Ford, and later on, even Chrysler's was also different) and absolutely not interchangeable. Has that changed now? And if it has not, which one is recommended for MTs?

Regards
Sutripta BHPian  
Join Date: May Location: DL 1 Posts: 367 Thanked: 13 Times Re: Lower Viscosity Oil in Gearbox - Pros and cons? Quote: Originally Posted by sgiitk One additive which a lot of people in the UK swear by is something containing Molybdenum (Liquid Moly or something). All sorts of miracles are claimed for it. there seems to be some logic there. my car's manual has this entry in the "lubricants and greases for transmission" section:

molybednum disulphide,lithium-soap based grease, water-resistant N.L.G.I. consistency =2 : MRM 2 : CV joints.

Tutela MRM2

Molybdenum disulfide - Wikipedia, the free encyclopedia Senior - BHPian  
Join Date: Nov Location: Germany Posts: 2,855 Thanked: 1,545 Times Re: Lower Viscosity Oil in Gearbox - Pros and cons? Quote: Originally Posted by Sutripta Hi,
AFAIK, EP is specifically not recommended for gearboxes. Only for hypoids. At least that was the case till a few years back. Yes! EP- Extreme pressure is preferred for Hypoids due to the tremendous heat generated due to localized tooth pressures, is this applicable to GB also? How does this EP oil affect the Synchros then?


Quote: Maybe basic lube chemistry has changed recently. Dada, good one!

Spike