Additive Chemistry Components IV

[MolaKule]

This specialized component can be calcium- or magnesium-based and is used in finished Manual Transmission (MTF) lubricants. Describe (in your own words) the primary purpose AND mechanical action of this component in Manual Transmission fluids? This question is not open to Engineers, Chemists, Formulators, or Tribologists. Swipes and YouTube dumps do not qualify as a valid answer.

 

[ZraHamilton]

They inhibit the corrosive effects of sulfur and phosphorous.

 

[MolaKule]

I'll give some Hints: primary <span style="font-style: italic">purpose</span> AND <span style="font-style: italic">mechanical action</span> with regards to <span style="font-style: italic">Synchronizers</span>.

 

[double vanos]

Just guessing here: Primary purpose : smoother shifts Mechanical action: provide friction for synchros to enable the smoother shifts.

 

[MolaKule]

Getting warmer

 

[Elevguy]

To do with yellow metal

 

[MolaKule]

Originally Posted By: double vanos

Just guessing here: Primary purpose : smoother shifts Mechanical action: provide friction for synchros to enable the smoother shifts.

OK, but what do we call the parameter that promotes smooth shifting?

 

[MolaKule]

Another hint to help you with the proper Terminology: https://www.bobistheoilguy.com/forums/ub...ion#Post1111352

Quote:

Describe (in your own words) the primary purpose AND mechanical action of this component in Manual Transmission fluids?

 

[CR94]

Friction modifier?

 

[MolaKule]

Specialized calcium and magnesium chemistry are part of the MTF additive package that promotes smooth shifting. These components give rise to Dynamic Friction Coefficients which change friction coefficients with the pressure applied to the surfaces of the synchro assemblies at time of engagement and dis-engagement.. CR94 nailed it with double vanos coming in second and both receive the BITOG virtual coffee Mug.

 

[CR94]

I've driven manual-transmission cars and trucks (and tractors) most of my life (until acquiring the Prius in late 2014), and ironically none of them specified or used specialized oil made specifically for manuals. (e.g., Type F ATF in the Mazda, SAE 90 or 80W-90 hypoid gear oil in my previous cars, engine oil in borrowed Hondas ... ) Yet, they somehow managed to shift OK.

 

[MolaKule]

Originally Posted By: CR94

I've driven manual-transmission cars and trucks (and tractors) most of my life (until acquiring the Prius in late 2014), and ironically none of them specified or used specialized oil made specifically for manuals. (e.g., Type F ATF in the Mazda, SAE 90 or 80W-90 hypoid gear oil in my previous cars, engine oil in borrowed Hondas ... ) Yet, they somehow managed to shift OK.

oK, how about:

Quote:

This specialized component can be calcium- or magnesium-based and is used in MODERN, DEDICATED, finished Manual Transmission (MTF) lubricants.

 

[CR94]

Originally Posted By: MolaKule

... This specialized component can be calcium- or magnesium-based and is used in MODERN, DEDICATED, finished Manual Transmission (MTF) lubricants.

Understood. How long has that "MTF" been common in mundane cars? Just in time to see manuals become an endangered species... In 1998, at about 360k miles, my Mazda had its most expensive mechanical repair, one of only two I didn't perform myself. That was replacing bearings in its transmission. Shortly after getting it back from the shop, I noticed it was burping oil out the vent in the top of the transmission housing, even though it was not overfilled. The oil was obviously not what Mazda specified (Type F), because it was higher viscosity and not pink. I called the shop to ask what it was. The guy said it was synthetic oil for transmissions, and "better" than Type F, therefore he would not change it. They couldn't (or wouldn't ) tell me specifically what brand and model oil it was. The transmission continued spitting the new thick oil out the vent, until it was dangerously low. I added ATF, repeatedly. Getting that stopped wasn't easy, but I finally succeeded. I never knew whether the oil loss was caused by the change in oil type, or by some mistake they made reassembling the transmission. The transmission went another ~240k with no further problems except being harder to shift into 2nd gear when cold than it had been before the repair. It was quieter than when new.

 

[MolaKule]

Originally Posted By: CR94

...How long has that "MTF" been common in mundane cars?...

Since about the early '70's for transmissions to be used in the Alaskan oil fields.

Quote:

One of the first of these dedicated MT fluids were the GM Synchromesh series of fluids in the viscosity range of API 5W30 engine oils, or the SAE Gear Oil 80W85 range, or 10.5 [email protected] These fluids were originally targeted for the GM series of synchromesh transmissions. Purported to have been formulated by Texaco, these early MT dedicated GM fluids were partial synthetic fluids that contained a synthetic oil component of alkylated benzene for low temperature operation.

 

[MolaKule]

Well, we'll give him the benefit of a doubt that he placed the [/quote] in the wrong place.