Manual Transmissions and Lubricants

[MolaKule]

Quote:
(I believe their claims to it being up to GL-4 specs have to do with the D4's inherent shear-stability, due to PAO/POE basestocks, and a stout addpack. )



I can accept the shear stability but the addpack is still a DexIII/Merc universal addpack.

If you intend to continue to use the ATF I would certainly do VOA's/UOA's and trend your wear.

I still think the Redline MTL70W80 or the Pennzoil Synchromesh would be better.

 

[mechtech2]

I don't believe the engineers ever thought that the carbon synchros and ATF was the absolute best possible materials combination.
They were told to use ATF [a common cheaper fluid], or make it suitable for ATF.
Engineers are cut off,hamstrung, and 'outsmarted' all the time in the auto industry.

 

[martinq]

How would the FM for the clutch material in an AT differ from that in a carbon-faced synchro? We're getting away from brass-to-steel friction an into clutchpad-to-steel.

My guess is the clutch-lining for both is very similar but I haven't found any info about this. On the same line of thought, would the clutch material used in a wet-DCT be significantly different from the wet clutch action in an AT or lined synchros?

 

[martinq]

Something else to add from the Red Line MTF PDS:


"The D4 ATF provides the best low-temperature shiftability.

MTL® provides better wear protection in most manual transmissions which call for an ATF which can be very important in racing applications. MTL® provides the low-temperature properties equivalent to a petroleum ATF.

All Red Line transmission lubricants provide excellent synchronizer compatibility."


That's telling me that D4 has the same 'synchronizer compatibility' (brass FM) as the other MTFs listed. Unless by compatibility they're not talking about performance.

 

[martinq]

After looking over the Red Line MTF specs I wondered how Motul Gear 300 would fit in. I did a compare using Widmans viscosity graph and came up with this:

If the numbers in the PDS are to be believed, then the Motul oil really is a 70w90 and not a 75w90. It looks like the Gear 300 is equal in viscosity to Red Line MTL somewhere around 1C and is thinner as temperature drops. At 100c the viscosity is just about equal to MT90.

These are excellent numbers if they can be believed or verified. I'm curious if there is a similar gear oil that is a bit thinner that might be a better all-around match for manual transmission use that don't need the SAE 90 gear-oil spec.

 

[dailydriver]

Originally Posted By: mechtech2
I don't believe the engineers ever thought that the carbon synchros and ATF was the absolute best possible materials combination.
They were told to use ATF [a common cheaper fluid], or make it suitable for ATF.
Engineers are cut off,hamstrung, and 'outsmarted' all the time in the auto industry.


^^^Yes, this could also be what Dave was implying in his response.

The earlier Borg Warner, and Tremec f body T-56es were actually a cellulose composite facing on the blocker rings, and only the latter ('01-'02 f body), and ALL of the Corvette C5/Z06, and Viper T-56es had carbon fiber faced blockers.

 

[dailydriver]

Originally Posted By: MolaKule
Quote:
(I believe their claims to it being up to GL-4 specs have to do with the D4's inherent shear-stability, due to PAO/POE basestocks, and a stout addpack. )



I can accept the shear stability but the addpack is still a DexIII/Merc universal addpack.

If you intend to continue to use the ATF I would certainly do VOA's/UOA's and trend your wear.

I still think the Redline MTL70W80 or the Pennzoil Synchromesh would be better.





So in other words just live with the cold weather start-out sluggishness and very slight grinding of the thicker MTLs/MTFs in order to save the gearbox internals overall??

 

[dailydriver]

Originally Posted By: martinq
After looking over the Red Line MTF specs I wondered how Motul Gear 300 would fit in. I did a compare using Widmans viscosity graph and came up with this:

If the numbers in the PDS are to be believed, then the Motul oil really is a 70w90 and not a 75w90. It looks like the Gear 300 is equal in viscosity to Red Line MTL somewhere around 1C and is thinner as temperature drops. At 100c the viscosity is just about equal to MT90.

These are excellent numbers if they can be believed or verified. I'm curious if there is a similar gear oil that is a bit thinner that might be a better all-around match for manual transmission use that don't need the SAE 90 gear-oil spec.


The gear 300 is GREAT stuff, with an almost unbelievable VI, but it is still WAAYYY TOO THICK to be used in a/my T56 at full operational temps.

It WOULD BE in my diff/axle if I lived inside the Arctic Circle (especially in winter), to take advantage of that VI!!

 

[ClutchDisc]

I definitely agree that stick shift is fun to drive!
Originally Posted By: mechtech2
MolaKule left out that most important scientific part...

Stick shift is fun to drive!
But Molakule didn't leave that out:
Originally Posted By: MolaKule
I think manual (or Stickshift or Standard) transmissions are more fun to drive than automatic transmissions. Manual transmissions require more driver interaction than do automatic transmissions. You can’t talk on the cellphone, or eat, or text when you have to shift gears.

 

[SOHCman]

Originally Posted By: ClutchDisc
I definitely agree that stick shift is fun to drive!
Originally Posted By: mechtech2
MolaKule left out that most important scientific part...

Stick shift is fun to drive!
But Molakule didn't leave that out:
Originally Posted By: MolaKule
I think manual (or Stickshift or Standard) transmissions are more fun to drive than automatic transmissions. Manual transmissions require more driver interaction than do automatic transmissions. You can’t talk on the cellphone, or eat, or text when you have to shift gears.

 

[[RT] ProjUltraZ]

Originally Posted By: molakule
The earlier Borg Warner, and Tremec f body T-56es were actually a cellulose composite facing on the blocker rings, and only the latter ('01-'02 f body), and ALL of the Corvette C5/Z06, and Viper T-56es had carbon fiber faced blockers.

thank you for the article! Yes, they use the carbon blockers when rebuilding those T-56s. Dave also told me a few yrs ago the MTL would be safe in those.

 

[dailydriver]

Originally Posted By: [RT
ProjUltraZ]
Originally Posted By: molakule
The earlier Borg Warner, and Tremec f body T-56es were actually a cellulose composite facing on the blocker rings, and only the latter ('01-'02 f body), and ALL of the Corvette C5/Z06, and Viper T-56es had carbon fiber faced blockers.

thank you for the article! Yes, they use the carbon blockers when rebuilding those T-56s. Dave also told me a few yrs ago the MTL would be safe in those.


He (Dave) tries to push people to use the D4 in their T56es ONLY because that is what the book/Helms factory manual says to use, but yes, when pushed (especially for road race/high ambient temp use), he admits that the MTL is also GREAT.

He has even endorsed an MTL/D4 mix to get the benefits of BOTH fluids in certain conditions/uses.

 

[[RT] ProjUltraZ]

thanks daily, the mix looks interesting i might try it by draining half the ATF and saving it and adding half MTL