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Re: please help GL4 GL5 gear oil questions [Re: Fsharp] #5114910 05/24/19 08:43 PM
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the13bats Offline OP
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Originally Posted by Fsharp
Heavy Duty 50wt transmission oil is a good gl-4 fluid for transmissions too. Mobil delvac Or Lucas are some popular ones I think they’re a little thicker than 75w-90. Yellow metal safe.


i was under the impression the mobil delvac is synthic so i stopped my reaserch there, neither of my old cars vw or vette have synth friendly seals, i would suspect most rebuilders do use synth compatible seals but i know my vw is old stuff and my vettes trans and diff while rebuilt are unknown.

Re: please help GL4 GL5 gear oil questions [Re: the13bats] #5114958 05/24/19 09:29 PM
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Originally Posted by the13bats
Originally Posted by Fsharp
Heavy Duty 50wt transmission oil is a good gl-4 fluid for transmissions too. Mobil delvac Or Lucas are some popular ones I think they’re a little thicker than 75w-90. Yellow metal safe.


i was under the impression the mobil delvac is synthic so i stopped my reaserch there, neither of my old cars vw or vette have synth friendly seals, i would suspect most rebuilders do use synth compatible seals but i know my vw is old stuff and my vettes trans and diff while rebuilt are unknown.


Well... I don’t believe in synthetic friendly or un-friendly seals. Maybe synthetic oil would dissolve some sludge or varnish and uncover a leak, especially in engine oil, but otherwise it’s fine. My opinion of course.

Re: please help GL4 GL5 gear oil questions [Re: Fsharp] #5115059 05/25/19 12:22 AM
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i dont know if its about belief, but in my research i have seen the reasoning that the seals were ready to leak or crude got dislodged whatever but i have also seen some high end guys say old seals were not synth safe, it does seem a bit odd and and new seals are gonna be likely synth safe anyway, im parroting what i have read in more than one place, i will be sure to ask the big 4 speed guru i know.

my personal opinion isnt cut in stone synth tends to be thinner and thinner leaks easier than thicker, and its possible
it attacks old antique seals, look at products that claim to fix leaks they must do something to the seals as i have seen people use it and it work.
in my case, my vw gets what vw specs, antique fluid, lol.

when i rebuild my rockcrusher i will still run non synth fluid as ive read too much that says people had syncro issues with synth in old muncies, a lot of my choices are based on superstition and budget, i cant gamble something might work when i know something else will work.

Re: please help GL4 GL5 gear oil questions [Re: Kamele0N] #5115198 05/25/19 08:15 AM
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Originally Posted by Kamele0N
@Molakule...

Toyota specs GL4/GL5 fluids in their MTs (as that you can use whatever spec you want)...

1) how can they claim that?

2) I changed MT fluid to Motul Motylgear 75w90 wich is GL5...MTs shiftings are quite stiff when oil is cold...would that normalize if I switch to GL4 75w90 gearoil?

Which toyota are you referring? Toyota japan actually recommend gl3/gl4 for corolla, so far my toyota shift the best with redline mt90. It hate motul gear 300, mobil 1 shc, redline ns 90, mt85. The other one that seems good for short period is shell spirax.

Re: please help GL4 GL5 gear oil questions [Re: the13bats] #5115337 05/25/19 11:35 AM
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LC J9....manual states GL4 or GL5...
GL5 shifts ok now in summer but MT is stiff/notchy in winter time...

And after MT gearoil change I went on a reputable offroad web site to see what their oiltool gives you for a J9 and cooy all those parameters...kv40 kv100 GL5 etc...

Last edited by Kamele0N; 05/25/19 11:48 AM.

2008 Toyota Yaris 1ND-TV 1.4 D4-D Tech9 5W30 C3 VW 504/507
1997 Toyota Landcruiser KZJ95 3.0 TD Elf Evolution NF900 5W40
Re: please help GL4 GL5 gear oil questions [Re: the13bats] #5115570 05/25/19 04:24 PM
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Originally Posted by the13bats
i dont know if its about belief, but in my research i have seen the reasoning that the seals were ready to leak or crude got dislodged whatever but i have also seen some high end guys say old seals were not synth safe, it does seem a bit odd and and new seals are gonna be likely synth safe anyway, im parroting what i have read in more than one place, i will be sure to ask the big 4 speed guru i know.



I'm hesitant anytime someone makes a statement like that. Any vehicle made within the last 20 years is likely using a modern elastomer (FKM) for the various oil seals in a vehicle. Newer vehicles use Teflon. In either case with these materials, a conventional vs synthetic oil is not chemically different enough to just suddenly cause a compatibility issue on its own. I could see the seal getting hard and wearing out over time naturally, but for the most part oil is oil.

Re: please help GL4 GL5 gear oil questions [Re: MolaKule] #5116840 05/26/19 10:20 PM
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Originally Posted by MolaKule
[quote=nobb]

I'm hesitant anytime someone makes a statement like that. Any vehicle made within the last 20 years is likely using a modern elastomer (FKM) for the various oil seals in a vehicle. Newer vehicles use Teflon. In either case with these materials, a conventional vs synthetic oil is not chemically different enough to just suddenly cause a compatibility issue on its own. I could see the seal getting hard and wearing out over time naturally, but for the most part oil is oil.


Exactly, the seal issues with synthetics were solved a long time ago.


1)
Originally Posted by bats
synth tends to be thinner and thinner leaks easier than thicker, and its possible


No, Synthetic differential gear oils and conventional gear oils of the same grade are exactly the same viscosity. Another internet misinformation tale. A badly worn seal is going to leak regardless of the viscosity of the oil or its base type.

https://www.bobistheoilguy.com/viscosity-charts/

MTL SPECIFIC fluids are slightly lower in viscosity for the same grade and use a different mix of base oils to improve cold weather shifting.

For a synchronized transaxle or transmission, one should use a GL-4 rated MTL SPECIFIC fluid because it has additive components that GL-5 differential lubes do not.


2)
Originally Posted by bats
...when i rebuild my rockcrusher i will still run non synth fluid as ive read too much that says people had syncro issues with synth in old muncies,


But your original question was about a transaxle in a trike.

Old Munices with decent synchro assemblies love the newer MTL fluids because they contain the proper friction modifiers which are great for the synchros.

3) Where are you going to find a fluid that does not have a synthetic component?


Originally Posted by bats
sounded easy but no, im in central fl, eustis and nothing i have found walk in carries a GL4 gear lube so i start my homework on it, while it would seem there is a ton of both facts and misinformation all jumbled together with lots of people just parroting what they heard, i do want to run fluid that wont kill my transaxle so i need the real deal on it.


4) And there are a number of technical articles on BITOG that explains differential and MTF fluids but it seems you have made up your mind regardless of the info you have received here.

Gear Tribology and Lubrication


Originally Posted by MolaKule
Manual Transmission (MT) Lubricants (Updated 5/20/2019)

Ever since dedicated MT fluids appeared on the scene (such as the GM Synchromesh series of fluid), drivers have seen better shifting due to better synchro engagement and improved shifter-fork movement, attributed to the specialized additive package used in these lubes. Before these fluids were introduced, engine oil’s such as 5W30 or gear lubes such as 75W90’s were specified, depending on design.

Note: This white paper is directed toward light truck and passenger vehicle manual transmissions. We will not be discussing transmission lubricants for Heavy Duty truck transmissions or those transmissions requiring MT-1 rated lubricants.

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. The AW component was primarily a reduced level of EP additives with a low level treatment of ZDDP for anti-oxidant purposes. Later, the EP additive was dropped for increased levels of ZDDP as the primary AW additive. Today’s MT fluids contain a multi-functional phosphorus chemistry as the primary AW additive with increased levels of synthetic fluids.

Then along came Pennzoil which introduced “Pennzoil Synchromesh” MTF with a 9.3 [email protected] viscosity. This fluid fulfilled the specifications for both GM and Chrysler manual transmissions as their factory fill. Later, companies such as Amsoil and Redline introduced MTF’s in various viscosities.

These fluids were successful because they introduced a specific friction modifier chemistry that insured smooth synchro engagement and disengagement.

Dedicated or Application Specific MTF’s for Manual Transmission or Transaxle use an additive package containing Anti-Wear (AW) additives, rust and corrosion inhibitors, emulsifiers, and specialized Friction Modifiers, and are generally protection rated at the SAE GL-4 level.

Now GL-4 does not necessarily refer to MTF’s, as there are some gear lubes in the
Market place that are GL-4 rated, but are not MTF’s. GL-4 is an SAE wear protection rating.

There are a few MT fluids GL-5 rated for specific vehicles that have common MT and Differential sumps. One such manufacture, Subaru, has transmissions which shares a common sump and require a MTF which is GL-5 rated.


Manual Transmission fluids use a different Friction Modifier for synchro engagement,
a modifier that is NOT the same Friction Modifier chemistry as used in differential lubes,
engine oils, or hydraulic fluids.

Here, Friction Modifier or Friction Modification does NOT refer to friction reduction.
Here, Friction Modifier refers to a chemical compound that gives rise to a situation
such that the coefficient of friction (COF) varies Dynamically with respect to the
relative speed of parts that mesh and de-mesh during engagement and disengagement of rotating parts.

(For a similar discussion of ATF’s and friction modification, please see: https://bobistheoilguy.com/forums/u...TF_and_Friction_Modification#Post1111352 ).


When selecting a replacement fluid for a manual transmission or transaxle, one has to consider the viscosity of the fluid for which the manual transmission or Transaxle was designed. The spectrum of viscosities for light truck and passenger vehicle transmissions now range from 6.0 [email protected] to 75W90 viscosities and therefore a dedicated MTF can be any viscosity from 6.0 cSt with an approximate SAE 70-75W80 grade ( a viscosity or grade similar to ATF’s) to an equivalent SAE 75W90 grade viscosity of approx. 14.5 [email protected]

For example, if your transmission requires a [email protected] fluid, an SAE 75W90 fluid should be used. In some cases, a 75W85 synthetic fluid has been shown to provide better cold weather shifting, while still providing sufficient anti-wear protection and fluid film thickness. In many cases, one has to experiment with fluids of slightly different viscosities to determine which fluid works best in your local climate and specific transmission.

We should also mention that transmission wear can also require a change in viscosity as well. However, no OTC additive or change in viscosity will cure a transmission that has severe wear in its bearings, gear teeth, or synchronizer assemblies.

It is recommended that an examination of clutch engagement and a change in transmission fluid be done before rebuilding a transmission. For the latter, crunching and “notchyness” can be caused by the old fluid having been sheared (loss of viscosity) and the degradation of its additive chemistry.

Rather recently, many MT manufacturers have introduced fluid specifications for fluids with lower viscosities in the range of [email protected] to [email protected], a viscosity in the same range as ATF fluids. These fluids were specified primarily to increase fuel mileage in order to raise fleet fuel mileage figures.

Some fluid manufactures’ such as Royal Purple and the fluid supplier for GM, have developed MTF fluids in this viscosity range. These fluids are basically ATF fluids with a bump in the AW components.

One manufacturer, Tremec for example, currently specifies Dexron III/Mercon ATF fluids. It is the opinion of this author that the design of this transmission can only use ATF because of cold temperature operation problems. In earlier specifications, they specified higher viscosity MTF’s, while in the latest specification, they specify ATF’s, yet the internals are supposedly the same. 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. Now there are new low viscosity fluids on the market with improved additive packages. In terms of the composite materials used in the ring-blocker assembly of these transmissions, the friction modifiers in ATF’s do nothing for synchronizer operation. The shearing of the fluid at the interface is the primary means of dynamic friction modification.

Current MTF’s in the range of 8 cSt to 10 cSt, designed for metal-alloy synchronizer assemblies, have been shown to work in these same transmissions without blocker-ring degradation or excessive wear.

One last comment: MTF specific lubes we're developed for manual transmissions and transaxles, and not for differentials or industrial gear boxes, and vice versa. A differential lubricant is not a good choice for MT’s. A dedicated differential fluid of 75W90 with a GL5 rating usually has a higher viscosity than does an MTF in the same advertised grade, and will therefore cause shifting problems in cold weather. In addition, a differential lube does not contain the proper additive package needed for MTF’s, since it contains an Extreme Pressure additive package meant for highly loaded hypoid gearing.

In summary:

1. GL-5 and MT1 rated gear lubes have a higher viscosity than MTF's of the same SAE Gear Oil viscosity range,

2. GL-5 and MT1 rated gear lubes have a different additive package than do MTF's; MTF's contain Anti-Wear additives, GL-5 and MT1 rated gear lubes contain Extreme Pressure (EP) chemistry.

3. GL-5 and MT1 rated gear lubes have a different additive package than do MTF's; MTF's contain specialized Friction Modification chemistry; GL-5 and MT1 rated gear lubes containing LS additives have special Friction Modification chemistry that is different than what is found in MTF's.

Here is an updated list of dedicated GL-4 and a few GL-5 MTL's.

Much confusion over the viscosities (thickness) of MTF fluids is the result of the SAE gear oil charts and its ranges seen at:

https://bobistheoilguy.com/viscosity-charts/


NOTE: This list is only a “suggested” list of MTFs. It is not an endorsement of any one fluid, nor is it implied that any one fluid will cure problems in MTs that have design problems or those that have excessive wear.

A. These MTL fluids are closest to a Kinematic Viscosity of 6.X [email protected] (About the same viscosity as a Dexron VI) and SAE 70 or so:

1. Castrol Syntrans FE 75W,
2. BMW (Pentosin) MTF-LT-3,
3. Honda MTII or MTF 2.
4. Ford FML-XT-11-QDC
5. Volvo Manual Transmission Fluid (6.4 cSt) [Recommended for: type M65 5-speed with 6-cyl. engine, M66, MTX75 and MMT6 and of the type M56, M58 and M59 from and including model year 1996. Meets Ford specification WSSM2C200-D2]
6. Redline MT-LV SAE Viscosity Grade 70W/75W Vis [email protected]°C


B. The next higher viscosity MTL would be the 7.0 to 7.6 [email protected] versions (SAE 70W75) (About the same viscosity as the original DexronIII/Merc)

1. Royal Purple's Synchromax
2. Ravenol MTF-2
3. Honda MTF
4. VW part number G052512A2
5. GM Manual Transmission and Transfer Case Fluid
6. BMW (Pentosin MTF 2) MTF-LT-1, 2 ,3
7. Tutelo (Petronus, Italy, Product Code 1402)
8. Pentosin Pro Gear 70W75 (Australia)
9.0 Pentosin FFL-4
10. Redline Power Steering Fluid
11. RAVENOL STF








C. The next higher viscosity MTL group is in the 8.0 cSt to 8.9 cSt Range would be:

1. Castrol Syntrans V FE (8.0cSt)
2. Redline DCTF Dual Clutch Transmission Fluid (8.1 cSt)
3. BG Synchroshift II (8.2 cSt)
4. RAVENOL PSA


D. The next higher viscosity MTL group in the 9.0 to 9.5 cSt range is (SAE 75W80):

1. Mopar Type MS-9417 MTL 9.0 cSt
2. Valvoline MTF Part Number 811095 9.2 cSt
3. Pennzoil Synchromesh 9.3 cSt
4. RAVENOL PSA 9.5 cSt
5. RAVENOL SSG 9.5 cSt


E. The next group of MTL’s are in the 9.6 to 10.X cSt range (SAE 75W80):

1. Redline MTL 75W80
2. Amsoil MTF (9.7 cSt)
3. GM Synchromesh’s
4. Volvo MTF 645
5. Fuchs TITAN SINTOFLUID SAE 75W-80 synthetic MTF (Carries a GL-5 rating as well)
6. Lodexol (Morris Lubricants) MTF
7. Motylgear 75W-80


F. The next higher viscosity MTL would be a [email protected] and SAE 75W85:

1. Redline MT-85



G. The next higher viscosity MTLs in the 14-15 cSt (SAE 75W90) range would be:

1. Amsoil MTG
2. Redline MT-90
3. Castrol Syntrans Multivehicle 75W-90
4. Castrol Syntrans Transaxle 75w-90
5. Ford XT-75W90-QGT (Carries a GL-5 rating as well)
6. Ford MOTORCRAFT® Full Synthetic Manual Transmission Fluid XT-M5-QS
7. ACDelco 10-4059 GL-4 75W-90 Manual Transmission Fluid
8. RAVENOL TSG SAE 75W-90
9. LiquiMoly 75W-90 GL4

Last edited by MolaKule; 05/27/19 06:38 PM.

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Re: please help GL4 GL5 gear oil questions [Re: the13bats] #5116863 05/26/19 10:57 PM
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Quote
Manual Transmissions and Lubricant effects.

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. 

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 a different type of 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 index.


Synchronizer: 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. Anti-corrosion additives keep the anti-wear additives 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 may also need cooling, lubricant film, and 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).
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...manual+transmission&FORM=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



The commercial additive suppliers have validated the PI packages for GL-4 service when used with specific base oils.

The important thing to consider here is differences between the PI packages and base oils for ATF's versus dedicated MTLs.

The PI package and base oil for ATF's start out with very low (some may say, "very thin") viscosity oils and use additive components for wet clutch applications. The PI package for an ATF has less than 18% of the Anti-Wear (AW) chemistry found in MTLs.

The PI package and base oil for MTL's start out with higher viscosity base oils, use additive components targeted for synchronizer assembly applications, and have about 5.5 times more AW chemistry than do ATFs.
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GL-4, GL-5 is a protection rating, not a viscosity spec.

I know of no ATF that qualifies as a GL-4 gear lube, because it does NOT have the required level of AW protection needed to meet the GL-4 protection level, nor does it have the required friction modifiers. ATF’s were speced because of design problems and cold weather shifting.

Last edited by MolaKule; 05/26/19 11:01 PM.

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Re: please help GL4 GL5 gear oil questions [Re: the13bats] #5117396 05/27/19 03:24 PM
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As MolaKule list shows go with Redline MT-90. My 02 jeep 5 speed also had issues with yellow metal parts. Red line MT-90 clearly states on the bottle safe for yellow metal parts and recommends for Chrysler transmissions 161,000 miles no issues. Pennzoil also makes pennzoil synchromesh also safe on yellow parts. Nice Bike


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2010 Mountaineer 4.0
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Re: please help GL4 GL5 gear oil questions [Re: Kamele0N] #5117559 05/27/19 07:14 PM
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Originally Posted by Kamele0N
@Molakule...

Toyota specs GL4/GL5 fluids in their MTs (as that you can use whatever spec you want)...

1) how can they claim that?


According to having been tested using KRL shear and other tests and passing other SAE J306 tests they can claim both GL protection ratings. What they are trying to do is to cover both GL ratings with one fluid but it doesn't always work out for manual transmissions.

Originally Posted by Kamele0N
2) I changed MT fluid to Motul Motylgear 75w90 wich is GL5...MTs shiftings are quite stiff when oil is cold...would that normalize if I switch to GL4 75w90 gearoil?


I don't doubt you have cold weather shifting because it clocks in at 17.1 [email protected] viscosity rating. And it's friction modification level is about 750 ppm too low.

Most dedicated (specific) 75W90 MTL GL-4's fluids come in at about 14.5 [email protected]

Last edited by MolaKule; 05/27/19 07:40 PM.

Dr. Larry Fleinhardt: "You know, that term "dark matter" has always perplexed me. It fallaciously implies that the 95% of our universe that cannot be observed is some amorphous, eventless emptiness."
Amita Ramanujan: "I'm sorry?"
Dr. Larry Fleinhardt: "I guess it's all too human. Instead of admitting to the present limits of our knowledge, we just declare things to be unknowable." NUMB3RS
Re: please help GL4 GL5 gear oil questions [Re: the13bats] #5118007 05/28/19 09:58 AM
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Tnx...will try to change it for a GL4 sped oil in a future


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1997 Toyota Landcruiser KZJ95 3.0 TD Elf Evolution NF900 5W40
Re: please help GL4 GL5 gear oil questions [Re: Kamele0N] #5119286 05/29/19 01:25 PM
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Originally Posted by Kamele0N
Tnx...will try to change it for a GL4 sped oil in a future



Europeans are very lucky because it is VERY....VERY difficult to obtain GL-4 (ONLY) rated gear oil, especially if you go to a brick and mortar parts store.

I'm sure it isn't uncommon to see many different products available as GL-4 rating only in Europe.

Re: please help GL4 GL5 gear oil questions [Re: the13bats] #5119315 05/29/19 01:56 PM
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Yes you can get both ratings easily.... But GL5 is more common/frequent though.


2008 Toyota Yaris 1ND-TV 1.4 D4-D Tech9 5W30 C3 VW 504/507
1997 Toyota Landcruiser KZJ95 3.0 TD Elf Evolution NF900 5W40
Re: please help GL4 GL5 gear oil questions [Re: Kamele0N] #5119395 05/29/19 03:40 PM
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Originally Posted by Kamele0N
Yes you can get both ratings easily.... But GL5 is more common/frequent though.



I've tried to walk into numerous auto parts stores in the USA and look for GL-4 only and with only a rare exception (usually CRC Sta Lube 80w90 mineral oil) is the only one you'll find anywhere. It's really amazing it is so hard to find I almost wonder if it is something to do with our EPA regulations something in that GL-4 that makes it hard to produce here or what?

GL-5 is everywhere of course, usually with (limited slip additives) included.

Last edited by AC1DD; 05/29/19 03:40 PM.
Re: please help GL4 GL5 gear oil questions [Re: the13bats] #5120114 05/30/19 10:04 AM
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You can still try to get it as a OEM MT transmission oil...it will probablly be on a pricier side...but it seems that you dont have other options over the pond smile

VW 501.50 is GL4 75w90...according to this PDS
www.ematrans.bg/index.php/bg/masla/...oad/450_2365d747bd84af784bfee9a1eabeda68

Try to find it at local VW dealer....

Hyundai/Kia has their 75w85 in GL4....it is their OEM specification

Dunno for other auto brands....



2008 Toyota Yaris 1ND-TV 1.4 D4-D Tech9 5W30 C3 VW 504/507
1997 Toyota Landcruiser KZJ95 3.0 TD Elf Evolution NF900 5W40
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