Synchromesh Manual Transmission Lubricants

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Originally Posted by MolaKule
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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 cSt@100C (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 6.5cst@100°C

...

You still need to add Ravenol MTF-3, which I guess would be in the A. section
 
Originally Posted by babyivan
Originally Posted by MolaKule
...

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 cSt@100C (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 6.5cst@100°C

...

You still need to add Ravenol MTF-3, which I guess would be in the A. section


If you can send me the results of a VOA or the complete Properties from a PDS we'll certainly consider doing so.
 
Hello & sorry for the PM re-post. Newbie mistake.
I noticed that Motul Gear 300 is absent from the list of Synchromesh Manual Transmission Lubricants, despite seeing recommendations for its use in other threads, and despite the list including seemingly similar other GL-4/GL-5 transaxle products like the Fuchs TITAN SINTOFLUID, Subaru, and Ford Motorcraft.
Just wondering what the deal is on Motul Gear 300.
Thanks!
 
If anyone has a New Oil (VOA) analysis (preferred) or a detailed Oil Properties listing of any MTF not on the list I'll be glad to look at it and add it to the list if appropriate.
 
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Here is my latest listing:

NOTE: This list is only a “suggested” list of GL-4 MTFs. It is not an endorsement nor a critique 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 MTF fluids are closest to a Kinematic Viscosity of 6.X cSt@100C (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 6.5cst@100°C


B. The next higher viscosity MTF would be the 7.0 to 7.6 cSt@100C 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. Pentosin FFL-4
10. Redline Power Steering Fluid
11. RAVENOL STF

Note: C, D and E are often considered popularly as “synchromesh” fluids.

C.
The next higher viscosity MTF 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. Valvoline MTF Part Number 811095 8.8 cSt
  5. RAVENOL PSA (8.9 cSt)

D. The next higher viscosity MTF group in the 9.0 to 9.5 cSt range is (SAE 75W80):
  1. Mopar Type MS-9417 MTL 9.0 cSt
  2. Pennzoil Synchromesh 9.0 cSt
  3. RAVENOL SSG 9.5 cSt

E. The next group of MTF’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 MTF would be a 12.0cSt@100C and SAE 75W85:
1. Redline MT-85

G. The next higher viscosity MTFs 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-9
9. LiquiMoly 75W-90 GL4
10. Pennzoil 75W90 GL-4
11. Motul Gear 300 GL-4/GL-5 (Product Number 100118)
 
E. The next group of MTF’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
Regarding #2 above, I use Amsoil Synchromesh MTF in the ZF S6-40 in my 1995 Corvette. Amsoil Synchromesh is 5w30 and it meets the specifications of GM P/Ns 12345349 and 12345577, both which are 5w30. This list says it is 75w80 grade. I've heard many times that there are different viscosity ratings/scales for engine oil vs gear lubricants, and perhaps some other application-specific scales. Can anyone help me understand this? First, why are oils rated with different viscosity scales just because of the application? Aren't cSt properties the same across the board for any one oil? What are the different scales? SAE and ? Seems unnecessarily confusing.
 
Regarding #2 above, I use Amsoil Synchromesh MTF in the ZF S6-40 in my 1995 Corvette. Amsoil Synchromesh is 5w30 and it meets the specifications of GM P/Ns 12345349 and 12345577, both which are 5w30. This list says it is 75w80 grade. I've heard many times that there are different viscosity ratings/scales for engine oil vs gear lubricants, and perhaps some other application-specific scales. Can anyone help me understand this? First, why are oils rated with different viscosity scales just because of the application? Aren't cSt properties the same across the board for any one oil? What are the different scales? SAE and ? Seems unnecessarily confusing.


I would study this chart selectable from the Home Page:


Early on many manf. specified 5W30 or XWXX engine oils in transmissions because Dedicated (MTF Specific) Manual Transmission Fluids had not been developed to any extent..

Along came Delco/GM with a dedicated (MTF specific fluid) formula blended by Texaco called, "Synchromesh" and it had a 100C viscosity of 10.5 cst which by the chart link posted above, fell into the 5W30 engine oil viscosity. This was just after GM developed the synchronized manual transmission with an added brass synchronizer assembly.

So when you look at the chart link posted above for 100C kinematic viscosity, you will see that it falls within a 30 grade engine oil viscosity as well as an 80 Grade SAE Gear oil viscosity.

The problem with the SAE Gear Oil grade charts is that there is such a wide range of viscosities for any SAE Grade Gear oil, so we prefer to use the 100C viscosity when selecting a replacement MTF and ignore the SAE grade Gear Oil range.

For MTF's we usually refer to the 100C kinematic viscosity when choosing a replacement fluid since that viscosity implies a sufficient oil film thickness for the torque and horsepower to be transferred from the engine to the rear differential at the average temperatures encountered during operation.

Most MTF's for passenger vehicles and light trucks come with a GL-4 protection rating. This protection rating insures sufficient wear protection for gears, bearings, and the synchro assembly.

For most vehicles with simple transaxles a GL-4 protection rating is sufficient since the differential is of a Spider-Gear design.

Some MT's require a special MTF with a GL-4/GL-5 protection rating because the fluid is used in systems with a common sump in which the transmission gearing shares the same sump with a Hypoid differential. Since any Hypoid differential has high loading, a GL-5 protection rating is necessary.
 
from experience the Redline MT 90 works great in my VW 2001 O2J 5 speed + now the O6M 6 spd in my 2001 audiTT 225Q. in fact i was having shifting issues with amsoil recommended series 200 in the past + the MT 90 fixed it for sever thou more before the poor VW syncros got worse + i stripped the teeth off 5 th at 30 lb boost!!
 
Add TES-295 fluids to your list. cSt is 7.3, the same as Dexron III, but it is a full synthetic...


 
Last, GL-5 rated Mobil Delvac 1 Gear oil 75W-90, cSt 15.9....

 
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Last, GL-5 rated Mobil Delvac 1 Gear oil 75W-90, cSt 15.9....


As I stated in a previous post on this thread:

If anyone has a New Oil (VOA) analysis (preferred) or a detailed Oil Properties listing of any MTF not on the list I'll be glad to look at it and add it to the list if appropriate.

I don't willy-nilly add any MTF to the list that has not been vetted with respect to application and chemistry.
 
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Great discussion! I believe my question is relevant here, but feel free to let me know if I should post it elsewhere.

I'd like to top off some GL-4 synchromesh manual transmission fluid with either (1) synthetic 10W-30 motor oil or (2) universal tractor hydraulic fluid. The top-off will constitute 5-10% of the total fluid volume. No synchronizers, so I'm not not too concerned about mixing the different friction modifiers of each fluid. (Thanks for your insight on FM mixing, MolaKule!)

1. Is anyone aware of incompatibility issues associated with the proposed blends (e.g. foaming, precipitation, etc.)?
2. Would the 5-10% dilution severely reduce the GL-4 protection of the manual transmission fluid, or would the protection reduction be negligible?
3. Which fluid is best suited for this top-off, PCMO or UTHF? In terms of additive packge, I believe UTHF is a better match. I might prefer 10W-30, however, as it's a better viscosity match.

Here are some success and failure stories about mixing mtf/gear oil with PCMO.
I'd mix a quart of HMC's MTF (part no.08798-9031, white cap) with a quart of Mobil 1 10W-30. I can report that after approximately one year and 6K miles in an '02 Honda Si with 26K miles on the odometer, this nutty concoction seems not just adequate or "good" but great.
if you mix gear oil with motor oil ..you'll get spontanious foaming.
 
Great discussion! I believe my question is relevant here, but feel free to let me know if I should post it elsewhere.

I'd like to top off some GL-4 synchromesh manual transmission fluid with either (1) synthetic 10W-30 motor oil or (2) universal tractor hydraulic fluid. The top-off will constitute 5-10% of the total fluid volume. No synchronizers, so I'm not not too concerned about mixing the different friction modifiers of each fluid. (Thanks for your insight on FM mixing, MolaKule!)

1. Is anyone aware of incompatibility issues associated with the proposed blends (e.g. foaming, precipitation, etc.)?
2. Would the 5-10% dilution severely reduce the GL-4 protection of the manual transmission fluid, or would the protection reduction be negligible?
3. Which fluid is best suited for this top-off, PCMO or UTHF? In terms of additive packge, I believe UTHF is a better match. I might prefer 10W-30, however, as it's a better viscosity match.

Here are some success and failure stories about mixing mtf/gear oil with PCMO.

Your question is relevant but I would repost it here https://www.bobistheoilguy.com/forums/forums/atf-differential-trans-brakes-p-s.16/
 
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