There are some dual GL5/GL4 gear oils. I would expect they are fine for the syncros. Oil viscosity is only part of the smoother gear changes, friction modifiers are also used.
Manual transmission fluid
I am planning to replace my manual transmission fluid in the next days so I bought the Liqui-molly full synthetic fluid GL-5 but upon reading the characteristic of the GL-5, I learned that it has sulfurs that will eat out the syncros (yellow metals) so I sent it back. When I was about to buy the OEM VW/Audi, it describe it as a GL-5 specifications also, so here where you guys come into play. What do you know about it, what have been your experiences and what do you recommend. Upon researching this matter I read some good reviews about the Redline fluid (75w 80) which is thinner than the 75w 90 which would help for smoother changing gears in cold temperatures. My ride is a nice 2003, FWD, manual transmission. Any help is appreciated. Thanks.
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I've been wanting to change my trans fluid also. I've done searches many times on the net to find the 'best' fluid and all I can find is debate on which fluid is the right fluid for our cars.
To be specific about this topic, the longitudinal transmissions in the B5 & B5.5's only. The transverse mounted engine/transmissions do not apply to this topic. Those are a completely different animal.
There is heavy debate on GL4 vs GL5. There is the consenses that GL5 has sulfur in it, which will attack the 'yellow metal' (synchro's).
The problem with our transmissions is they need an oil that is thinner for the gear sets, but at the same time needs a heavier oil for the hypoid gears (ring and pinion).
Because of all this debate and me not being able to find any conclusive answer anywhere I've just left mine alone. And yeah, way in the back of my head it drives me nuts.
My 1998 GLS 5sp daily driver just hit 160K this week and the thought of that oil with all of those miles on it sends chills up my spine.
Over on one of the TDI forums Redline, Valvoline Synchromesh, Motul and Fuchs seem to be the popular brands, but again the ensuing debate rages on about what oil is the best / right oil.
Even VW's own Genuine oil is rated GL5 spec which contradicts earlier service bulletins to use GL3+ or GL4.
With all of this, the current GL5 spec from VW is a newer formula and I'm going to suspect it is a 'sulfur free' oil.
As any old school machinist will tell you, the cutting fluids (more specifically, the heavy cutting oils) from the old days contained sulfur and was far superior for heavy cutting, (milling, tapping, broaching) where high cutting forces and high heat were part of the process.
Now-a-days heavy cutting oil in the machining industry does not contain sulfur. Same holds true with most oils in the industry.
It's almost impossible to get anymore. It's like comparing gasoline from back in the day. Gasoline had an average 300ppm of sulfur all the way into the 70's.
Then the EPA started their deal and cracking down. Today gasoline is at 30ppm.
So with that being said, that is my personal reasoning for assuming the new GL5 trans oil is 'sulfur free'.
After all that winded rhetoric, I never really answered your question.
I guess in the end I'll just end up buying Genuine VW spec oil and go with that.
To be specific about this topic, the longitudinal transmissions in the B5 & B5.5's only. The transverse mounted engine/transmissions do not apply to this topic. Those are a completely different animal.
There is heavy debate on GL4 vs GL5. There is the consenses that GL5 has sulfur in it, which will attack the 'yellow metal' (synchro's).
The problem with our transmissions is they need an oil that is thinner for the gear sets, but at the same time needs a heavier oil for the hypoid gears (ring and pinion).
Because of all this debate and me not being able to find any conclusive answer anywhere I've just left mine alone. And yeah, way in the back of my head it drives me nuts.
My 1998 GLS 5sp daily driver just hit 160K this week and the thought of that oil with all of those miles on it sends chills up my spine.
Over on one of the TDI forums Redline, Valvoline Synchromesh, Motul and Fuchs seem to be the popular brands, but again the ensuing debate rages on about what oil is the best / right oil.
Even VW's own Genuine oil is rated GL5 spec which contradicts earlier service bulletins to use GL3+ or GL4.
With all of this, the current GL5 spec from VW is a newer formula and I'm going to suspect it is a 'sulfur free' oil.
As any old school machinist will tell you, the cutting fluids (more specifically, the heavy cutting oils) from the old days contained sulfur and was far superior for heavy cutting, (milling, tapping, broaching) where high cutting forces and high heat were part of the process.
Now-a-days heavy cutting oil in the machining industry does not contain sulfur. Same holds true with most oils in the industry.
It's almost impossible to get anymore. It's like comparing gasoline from back in the day. Gasoline had an average 300ppm of sulfur all the way into the 70's.
Then the EPA started their deal and cracking down. Today gasoline is at 30ppm.
So with that being said, that is my personal reasoning for assuming the new GL5 trans oil is 'sulfur free'.
After all that winded rhetoric, I never really answered your question.
I guess in the end I'll just end up buying Genuine VW spec oil and go with that.
Thank you PZ and AndreasPassat for your input, it helps a lot to know that I am not the only one worried about this. I'm still digging about this and read more interesting information here https://www.google.com/url?sa=t&rct...axle_oil.pdf&usg=AOvVaw1neW6ilOnAwS-CfNyPIeiR that may help others to make a decision of what to use to make their car last as much as possible. As for myself right now I am thinking on a GL4, synthetic, 75w 90 probably Pennzoil or Redline and will stay away from any GL5 or GL4-GL5 specs labeled product even OEM.
The people on the other forums like how butter smooth the shifts are with the Redline oil.As for myself right now I am thinking on a GL4, synthetic, 75w 90 Redline
I used 1L of Fuchs/Titan Sintofluid on my 01E 6sp as it meets VW/Audi specs VW 501 50 (G00500005 G005000 G00500020 G052911A1-A2).
https://advancedautomotion.com/shop/product_info.php/cPath/260/products_id/139
It's a bit notchy on the 1-2 when it's cold, but nearly all 01E are notchy on 1-2 when cold. It's also GL5 rated. I am going to try 1L of a Chrysler GL3 that is known to be easy on syncros and see if it makes a difference in the 3 months I will test it. If no change, it's the trans and I will go back to Fuchs as it's highly recommended on the S4 forums . You can get the Redline or Royal Purple GL4 at many auto parts stores.
Here are the Audi trans specs (same as Passat): https://www.audizine.com/forum/attachment.php?attachmentid=96950&d=1544459428
https://advancedautomotion.com/shop/product_info.php/cPath/260/products_id/139
It's a bit notchy on the 1-2 when it's cold, but nearly all 01E are notchy on 1-2 when cold. It's also GL5 rated. I am going to try 1L of a Chrysler GL3 that is known to be easy on syncros and see if it makes a difference in the 3 months I will test it. If no change, it's the trans and I will go back to Fuchs as it's highly recommended on the S4 forums . You can get the Redline or Royal Purple GL4 at many auto parts stores.
Here are the Audi trans specs (same as Passat): https://www.audizine.com/forum/attachment.php?attachmentid=96950&d=1544459428
^^^ did you go Chrysler GL3?
.
.
Haven't paid attention to the manual gearbox oil debates. But I picked up a 5 speed and I have Redline MT-85 laying around. Any qualms of me throwing it in there?
I did use the Chrysler GL3 but it did not make a difference. I sold the car, not sure what's in it now. The Redline MT-85 should be fine, but I don't know if it will be notchy when cold. That was more of an issue in the 6sp trans like I had. I bought 6L of the Fuchs, but I don't know if I sold it with the car or still have it stashed in the garage.
I used 1L of Fuchs/Titan Sintofluid on my 01E 6sp as it meets VW/Audi specs VW 501 50 (G00500005 G005000 G00500020 G052911A1-A2).
Titan Fuchs Sinto Fluid, Advanced Automotion
It's a bit notchy on the 1-2 when it's cold, but nearly all 01E are notchy on 1-2 when cold. It's also GL5 rated. I am going to try 1L of a Chrysler GL3 that is known to be easy on syncros and see if it makes a difference in the 3 months I will test it. If no change, it's the trans and I will go back to Fuchs as it's highly recommended on the S4 forums . You can get the Redline or Royal Purple GL4 at many auto parts stores.
Here are the Audi trans specs (same as Passat): Audizine Forums
I'll say, the 6speeds are PITA to get into 1st when cold, and even then after it's hot, sure isn't as smooth as the 5speed box.I did use the Chrysler GL3 but it did not make a difference. I sold the car, not sure what's in it now. The Redline MT-85 should be fine, but I don't know if it will be notchy when cold. That was more of an issue in the 6sp trans like I had. I bought 6L of the Fuchs, but I don't know if I sold it with the car or still have it stashed in the garage.
Always wondered if you could mix-n-match some of the synchros to enhance the 6speed shift-ability.
Uh Oh! Quote: "MTL, MT-85 and MT-90 are not for use in differentials with hypoid gears"
Our manual gearboxes have hypoid gears in the final drive.
Our manual gearboxes have hypoid gears in the final drive.
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