Synchromesh Manual Transmission Lubricants

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You bring up a number of interesting points. I am not going to read all of the comments on some other blog, but will attempt to respond to some of your comments.

A. My information on the paper/cellulose blocker rings on the 1998-2000 Tremec T56 manual transmissions is that they are actually blocker rings of kevlar/graphite/cellulose composites, similar in composition to the clutch disc material in Allison AT's.

B. The Tremec series has always been, in my view, a problem child with respect to fluid specs. In some cases, they speced this fluid, while in other cases they spec a different fluid, supposedly with the same internals. Why? My guess is they found that, with their original specs for the higher viscosity fluids, shifting was poor in cold weather, so they dropped the viscosity and at that point in time, the only available fluid with a low viscosity was ATF - which is no longer the case.

Why weren't other fluids, such as Pennzoil Synchromesh (9.3 cSt), and other slightly higher viscosity fluids tested? My guess here is that they had some design problems, either due to shifter clearances, or due to cluster gear shaft clearances.

C.
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At B. 5 on the list of MTL's GM's Manual Transmission and Transfer Case Fluid is listed. From what I've read, this is merely rebranded ATF (no license renewal on the old stuff), probably to satisfy the need to say they have what you require.


The fluid mentioned (GM product (#88861800)) is basically a Dexron III(H) fluid with additional AW levels of a phosphate/anti-oxidant chemistry.

D.
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Others have tried Synchromesh, synchromax, RP, Amsoil ATF, etc. with varying degrees of success. I read a number of blogs describing T56 failures using the higher grade MTL's in the pre-2001 models. I don't recall reading about any failures/problems associated with DEX III, Mobil syn ATF, or the GM MTL.


And most of these comments had no definitive cause-and-effect details as to why the trannies failed. Did anyone have their trannies examined by a competent transmission shop and a determination made of the failure? Was the cause of failure due to an increase in engine HP via performance chips, was it due to tracking not covered by warranty, was it due to inadequate maintenance, U-joint vibration, transmission mounts? What?

When we were blending, marketing and supplying customers with our own versions of MTF, including a low viscosity MTF (called "MTFGlide," 7.5 cSt (75W80)), and MTL-P (MTL Purple, 11 cSt, 75W85)) customer feedback showed no problems with the Tremec series of transmissions. These fluids had the same AW additives and friction modifiers as did our 75W90 MTF called MTL-R (14.5 cSt, MTL-red).
 
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I run the Tremec TR6060 in my 2014 GT500 on a mix of 1 quart Motorcraft MT-X5-QS (15.6 CST) and 3 quarts Motorcraft XT-11-QDC (6.4 CST) dosed with 1.5 bottles of XL-18 friction modifier. The calculated viscosity is between 7.5 and 8.0 CST and it shifts very well even when cold. The transmission also runs a lot quieter.
 
Molakule, this is all great stuff that I have not run across before. Thanks for posting this. More to think about. Maybe the blocker ring fluid is just a myth. Still, the swelled blocker ring "theory" has to come from somewhere. Most anyone doing a performance upgrade on the 1998-2000 LS1/T56 set ups is going to pull the trans/clutch and upgrade them as well. The weak link blocker rings, 3-4 shifter fork, etc. would be the first to go.

If you have any suggestions on early T56's with the cellulose blocker rings I'd more than welcome them. The idea of ATF in my trans has never quite sat well with me, despite the OEM recommendation. The ATF in my car is now 3 years old with 5K miles...car has 17K miles. No doubt a large % of these cars got to 75K-100K on those original transmissions using ATF. My car shifts fine both cold and hot. After changing the 14 year old FF with more ATF there was hardly any difference, if any. The longer term internal protection is what I'm after.
 
Consider these facts:

1. ATF contains less than 40% of the AW additives of dedicated MTF's of the same viscosity,

2. ATF or ANY fluid will cause a slight swelling (actually a volumetric increase) of ANY material containing kevlar/graphite/cellulose composites.

The questions are: How much and what are the resulting effects?

I once did a calculation of the volume increase from ANY fluid and it resulted in less than 0.1%. I.E., take any clutch material volume and multiply it by 0.00093.

So why does ANY fluid increase volume? Because a fluid displaces most of the interstitial spaces in the material.

If there is any affect, I would think this fluid would tend to "cushion" impacts during synchro engagement.

In my view, swelling or volume increase is greatly "overblown,"
and is an excuse for some failures due to design.
 
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And this needs to be said again regarding Friction Modifiers for MTFs':

We have to be careful about not stating inaccurate assumptions about MTF Friction Modifiers because friction modifiers for MTF's are NOT the same friction modifiers for ATF, are NOT the same friction modifiers for differentials fluids, are NOT the same friction modifiers for MO's, and are NOT the same friction modifiers for tractor wet clutches.
 
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What do the sensei think of this stuff?

61jxvemQTDL._SY355_.jpg



Googling for "Energear MP" seems to only get returns in Japanese, so it may be a Japan-only product or (more likely) packaging. I'd guess the MP stands for "Medium Pressure".

http://www.craigeng.co.nz/energear.htm

has info on "BP Energear Easy Shift" which MAY be the same stuff, and includes the statement "Particularly suited for manual transmissions in Japanese front wheel drive vehicles."

I'll probably be in Japan before the new year.
 
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Yes - it is Japan-only and does what it says on the tin. It's a GL-4/GL-5 multigrade transmission oil, targeted largely at the commercial vehicle sector. The "MP" probably stands for "multi-purpose", given its application for synchromesh gearboxes and final drives/rear axles.

It will not be the same as the Energear Easy Shift that you linked, because that is only GL-4 rated and has the statement "This product must not be used in differentials requiring an API GL 5 or higher performance level."
 
Originally Posted By: MolaKule
And this needs to be said again regarding Friction Modifiers for MTFs':

We have to be careful about not stating inaccurate assumptions about MTF Friction Modifiers because friction modifiers for MTF's are NOT the same friction modifiers for ATF, are NOT the same friction modifiers for differentials fluids, are NOT the same friction modifiers for MO's, and are NOT the same friction modifiers for tractor wet clutches.


Can I quote this, just to restate and underline it?!

Furthermore, friction modifiers in these various fluids are not the same as in the more commonly-discusses engine oils, where the application is to reduce friction - in a MT, AT, CVT, IVT etc you need to manage friction, which isn't always reducing it. There are cases where you want to increase friction.
 
Originally Posted By: weasley
Originally Posted By: MolaKule
And this needs to be said again regarding Friction Modifiers for MTFs':

We have to be careful about not stating inaccurate assumptions about MTF Friction Modifiers because friction modifiers for MTF's are NOT the same friction modifiers for ATF, are NOT the same friction modifiers for differentials fluids, are NOT the same friction modifiers for MO's, and are NOT the same friction modifiers for tractor wet clutches.


Can I quote this, just to restate and underline it?!

Furthermore, friction modifiers in these various fluids are not the same as in the more commonly-discusses engine oils, where the application is to reduce friction - in a MT, AT, CVT, IVT etc you need to manage friction, which isn't always reducing it. There are cases where you want to increase friction.


Be my guest.

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There are cases where you want to increase friction.


Exactly.

in the case of CVT fluids you want a traction coefficient to make sure the belt is in a proper "friction" marriage with the pulleys.
 
Originally Posted By: weasley
Yes - it is Japan-only and does what it says on the tin. It's a GL-4/GL-5 multigrade transmission oil, targeted largely at the commercial vehicle sector. The "MP" probably stands for "multi-purpose", given its application for synchromesh gearboxes and final drives/rear axles.

It will not be the same as the Energear Easy Shift that you linked, because that is only GL-4 rated and has the statement "This product must not be used in differentials requiring an API GL 5 or higher performance level."


Thanks.

So its multi-purpose, AND specified for manual transmissions, but not AS suitable for (most) manual transmissions as a dedicated GL-4 only MTL. Annoying.

Perhaps its like:-

"5. Fuchs TITAN SINTOFLUID SAE 75W-80 synthetic MTF (Carries a GL-5 rating as well)" and/or

"5. Ford XT-75W90-QGT (Carries a GL-5 rating as well)"

referred to above as suitable for Subaru's that have (hypoid?) diffs in the transmission.

http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3272731/Re:_Synchromesh_Manual_Transmi#Post3272731.

This poses the obvious, but perhaps un-answerable question: HOW unsuitable is it?

Its advantage is I can get it off the shelf, plus I already bought a litre. Wasn't very expensive and I took a chance, since I didn't know when I'd be back in Japan.

Don't have to use it, though.
 
Thought I'd post in this thread as the topic seems relevant.

Using this link
http://www.oilspecifications.org/volkswagen.php

Scroll down to "Volkswagen Gear Oil Specifications"

It states that gear oil VW G 052 171 is a SAE 70W75 viscosity gear oil.

Then underneath we have VW G 052 171 A2. No viscosity is mentioned it just says
"Special gear oil designed for the manual transmissions of cars with transverse engines."

What difference does the "A2" make (I think I've seen A1 also)

Or does this imply that all VW G 052 171 regardless of A1 or A2 are all SAE 70W75 viscosity gear oil?

Thanks folks!
 
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Originally Posted By: BLKGTTDI

What difference does the "A2" make (I think I've seen A1 also)

Or does this imply that all VW G 052 171 regardless of A1 or A2 are all SAE 70W75 viscosity gear oil?


I know this is an old post and I no longer own a VW, but from what I remember the A1 and A2 refer to container size.
 
Here is an updated version of the original White Paper:


Manual Transmissions and Lubricant effects.

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. 

In this paper we examine the internal mechanisms of the manual transmission and the effects of the lubricant’s viscosity and additives. We are discussing light truck and passenger vehicle manual transmissions. We will not discuss OTR or heavy-duty transmissions which use require a different type of lubricant, such as the MT1 rated lubricant.

A modern gearbox is of the constant mesh type, in which all gears are always in mesh. This constant mesh and the cut of the gears insure a rather quiet transmission. In any one gear, only one of these meshed pairs of gears is locked to the shaft on which it is mounted. The others are being allowed to rotate freely; thus greatly reducing the skill required to shift gears. Most modern cars are fitted with a synchronized gear box, although it is entirely possible to construct a constant mesh gearbox without synchromesh, as found in motorcycles for example.

Some manual transmissions are integrated with differentials to form a “Transaxle.” The differentials here are usually NOT the hypoid types found in larger vehicles, but are of the spider gear configuration. The exception is the Subaru system where the transmission and the differential share a common sump, hence the need for a GL-5 rated fluid.

Going from the top of the transmission case downward, we have the shifter mound which contains the shift lever and linkages. The shifter will have a seal or boot at the top with an additional gasket to keep the lubricant from flowing out when slung by the gearing. Below that are two shafts, one the input shaft and the other being the output shaft. The input shaft is splined to the clutch for power connect or disconnect. The output shaft goes to a universal joint, then to the driveshaft (a hollow “torque” tube), and the driveshaft connects to the differential via another universal joint.

An illustration of a basic manual transmission is found here, so exercise the shifting as we discuss the mechanisms (not a perfect illustration but makes the point):

http://auto.howstuffworks.com/transmission4.htm

Shifter Assembly: The gears resting on the top shaft, the input shaft, are locked onto that shaft and rotate at the same rpm as the engine. The bottom output shaft has synchronizers “splined” to this shaft, so they can move around as the gear ratio is changed. The gears on the output (bottom) shaft are allowed to rotate freely on the output shaft or on small roller or “needle” bearings, depending on the horsepower transmitted and the design. The output shaft will rotate at various rpms depending on gear selection. In first gear, for example, you want low output shaft rpm and high torque.

The shifter moves the associated linkage which connects to the shifter forks. The linkages position the shifter forks, and effectively “programs” the shifter forks in order to select the required gear ratio. I.E., for each shift lever position, the shifter forks are moved around to drive the splined synchronizers on the output shaft. The shifter forks have a bore so they can slide on the guide rods. There is a specified clearance between the shifter forks’ bore and the shifter fork guide rods.

Lubricant effects: Too high a viscosity lubricant and the shifting will be hard and sluggish. More force will be required to go from one gear to another. Too thin an oil and the forks will wear, the clearances will increase, and the shifting will become sloppy and uncertain. The correct mix of base oil viscosities is needed here to insure good cold weather and hot weather shifting. Synthetics excel here because of their high viscosity indices.


Synchronizer Assembly: The locking mechanism for any individual gear consists of a collar on the shaft which is able to slide sideways so that teeth or "dogs" on its inner surface bridge two circular rings with teeth on their outer circumference; one attached to the gear, one to the shaft. (One collar typically serves for two gears; sliding in one direction selects one transmission speed, in the other direction selects the other) In our illustration from above, the bottom or output shaft has splines that mate with the synchronizer “collar.” The synchronizer collar moves transversely on the splines, positioned by the shifter fork. When the rings are bridged by the collar, that particular gear is rotationally locked to the shaft and determines the output speed of the transmission by the synchronizer. In a synchromesh gearbox, to correctly match the speed of the gear to that of the shaft as the gear is engaged, the collar initially applies a force to a cone-shaped brass clutch which is attached to the gear, which brings the speeds to match prior to the collar locking into place. The collar is prevented from bridging the locking rings when the speeds are mismatched by synchro rings also called blocker rings. Notice, before locking and speed synchronization, a lot of shearing takes place at the interfaces and for the reasons given above. Most synchronizer materials are of brass, but newer synchronizers can be made of strengthened graphite composites.

Lubricant effects: A special Friction Modifier (FM) chemistry is incorporated into the additive chemistry to allow just the right amount of shearing before engagement. I.E., the FM gives rise to a specific dynamic coefficient of friction (COF) to allow engagement without “crunching.” Automatic Transmission Fluids (ATF) DO NOT have these specialized FM’s.

Note: the specialized FM used in manual transmissions is NOT the same FM used in Limited Slip Differentials, nor is it the same FM used in Automatic Transmissions. It is important to understand that there are different FM chemistries for different automotive applications!

Bearings: Lubricated bearings are used to reduce friction between rotating parts. The older Munice transmissions, for example, used brass or sintered brass sleeve bearings or bushings. Most modern transmission bearings today, as can be seen by the links given below, are of two main types 1) Roller or needle bearings, and 2) ball bearings. Ball bearings or tapered roller bearings are usually used at the shaft ends to resist radial and transverse loads. Smaller roller or pin bearings are used inside the driven gears that idle on the output shaft.

Lubricant effects: Depending on the horsepower transmitted and the size of the bearings, viscosities of the lubricants kinematic viscosities range from 6.0 cSt (ATF-range) to 14.5 cSt (equivalent to a light 75W90 gear lube) given at 100C. The anti-wear additives keep wear in check as they rotate in their races. Metal Inhibitors keep any other chemistry from attacking the synchronizers, and anti-rust additives keep any moisture from creating rust on the steel components. For lower horsepower drive trains, the lubricant must be thin enough to penetrate the cages in the pin/roller bearing areas. For higher horsepower drive trains, the lubricant must maintain a thick film in order to protect the bearing surfaces. Of course, the lubricant is also used for cooling. Too thick a lubricant will cause poor cold weather performance and loss of mpg, while too thin a lubricant will cause undue wear. The lubricant also transfers heat from the bearings and gearing to the case.

Gearing: Most gear types in manual transmissions are of the helical type, which because of the cut, reduce noise and vibration. Due to their angular cut, thrust loads are transmitted to the shafts on which they reside. Lubricant effects: Being in constant mesh, they are dipping in the oil bath and slinging the oil up to the shifter assembly. Since they transmit torque, they must have an anti-wear/Extreme Pressure additive in the lubricant in order to reduce wear. The slipping and rolling action of the gear teeth causes localized high pressures and heating. The anti-wear additive forms a protective but complex ferrous film at the contact surface to protect from galling and other wear mechanisms.

Other components such as thrust washers and shims also need anti-wear additives as well.


Note: In the past reduced levels of EP additives were part of the MT fluid formulation, but modern formulations use chemistries such as Multi-Function Phosphate esters, ZDDP, metal and rust inhibitors, Viscosity Index Improvers, and synthetic base oils.


Rebuilding manual transmissions usually require only a modest rebuild kit consisting of bearings, synchronizers, and seals unless the transmission has been abused or the wrong lubricant has been used. In that case, gear teeth need to be examined for any chipping, galling, breakage, or other signs of problems.

(Transmission Kits).

(Transmission Kits).
http://www.manualtransmissionkits.com/nv4500_bk308ws_bearing_kit_rebui.htm

Here are some individual transmission parts layed out for Jeep transmissions but is typical of others.

http://www.4wd.com/Transmission-and-Transfercase/Manual-Transmissions.aspx?t_c=69&t_s=239
Images of Manual Transmissions, both external and internal:
http://www.bing.com/images/search?q=manu...ORM=IGRE#x0y810

If you are going to modify or rebuild your Manual Transmission, I highly recommend this book or equivalent:

http://www.mre-books.com/transmissions/rebuild_and_modify.html
Passing Thoughts

A variation on the Manual Transmission is the “Automated Manual” using a dual clutch. Some people consider many of the Honda Automatic Transmission simply automated manual’s as well.

http://www.allpar.com/corporate/auto-manual-transmission.html
A long winded History and Summary but without the in-depth knowledge of internal

mecahnics-vs-lubricants:
http://dictionary.sensagent.com/Manual_transmission/en-en/

I like this link; it contains online MT manuals for classic Chevy’s:
http://chevy.oldcarmanualproject.com/trans/index.htm
 
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So why is the performance of Pennzoil Synchromesh so much worse than the original GM version? The Pennzoil is cheaper. The GM version shifted much better than the Pennzoil version especially in cold weather.

Perry
 
The GM version contained some a synthetic base oil component that allowed a better viscosity in cold weather.
 
My car has a Laycock de normanville overdrive fitted to the manual transmission, the units share the same transmission oil. The O/D incorporates a wet cone clutch.

There are various recomendations for lubrication oils when this unit is fitted to a transmission, but some recomendations date back to the 1950's.

The transmission and O/D has been performing well with Pennzoil Syncromech, but I wonder if something else might be better?
 
My one MT specs 20W-50 engine oil from the factory, so this is what I use in it. At one point I used Redline MT-90 to try and buy some time on failing synchros, but in the end just changed the transmission(and dumped $60 worth of Redline in the process).

The general consensus from folks who opt to use MT-specific lubes in these boxes is that MT-90 is the best choice, although a lot still argue for using 20W-50.

Also, hopefully before the end of the year I'm going to be fitting an O/D transmission with the same set-up as the previous poster(Laycock electric O/D with cone clutch and sharing fluid with the gearbox). There again, a lot of folks run 20W-50 in O/D in these transmissions, but I've also heard arguments for using MTL over MT-90 in O/Ds.

Any thoughts from the experts here on that? I will say that the transmission is awfully stiff when the outside temperatures are cold and the car is cold, although it certainly loosens up in driving. The MT-90 made my old transmission seem to shift smoother, aside from the 3rd gear grind(I'm told that particular synchro is the weakest part in this otherwise indestructible box).
 
If that is the MBG, then when that gearbox was used for a commercial application (J4 van) they speced EP90. Same viscosity as 20W-50 just a bit more robust in a gearbox.
 
For the Laycock de normanville overdrivesystem and tranny I would stick with something like MTL-75W85 or MT-90.


The reason for the old 20W50 spec was the then current mineral oil would shear down in viscosity under heat.
 
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