Motul Gear Competition & Brass/Yellow parts

[fbdewar]

Motul gear competition is GL5 rated which normally means not good for brass synchros and other yellow parts but the marketing on their website says for all synchronized and non synchronized gear boxes and another product page, although not Motuls, says it's yellow parts compatible.
I've emailed their tech support but haven't gotten a response.
Anyone familiar with this oil and whether it's ok to use in a transmission with brass synchros?

Thanks much for any help/clarity!

 

[The Lube Guy]

You're probably talking about Motul Competition 75W-140. It's blue colored GL-5 gear oil. It's very good, but unsuitable for yellow metals. Don't use it. If you ever used Red Line gear oil, then you should know that Motul Competition smells like Red Line, but stronger. It's got that strong gear oil smell.

Keep in mind that there are carbon fiber synchronizers like the one in the picture bellow. If your transmission/gearbox calls for GL-4 fluids, don't use GL-5. You can, however, use a dual GL-4/GL-5 gear oil in your gear box if you wish, as it won't harm yellow metals.

 

[fbdewar]

You're probably talking about Motul Competition 75W-140. It's blue colored GL-5 gear oil. It's very good, but unsuitable for yellow metals. Don't use it. If you ever used Red Line gear oil, then you should know that Motul Competition smells like Red Line, but stronger. It's got that strong gear oil smell.

Keep in mind that there are carbon fiber synchronizers like the one in the picture bellow. If your transmission/gearbox calls for GL-4 fluids, don't use GL-5. You can, however, use a dual GL-4/GL-5 gear oil in your gear box if you wish, as it won't harm yellow metals.

View attachment 223897

You're helping me out all over! Thank you I'll look for another fluid.

 

[fbdewar]

You're probably talking about Motul Competition 75W-140. It's blue colored GL-5 gear oil. It's very good, but unsuitable for yellow metals. Don't use it. If you ever used Red Line gear oil, then you should know that Motul Competition smells like Red Line, but stronger. It's got that strong gear oil smell.

Keep in mind that there are carbon fiber synchronizers like the one in the picture bellow. If your transmission/gearbox calls for GL-4 fluids, don't use GL-5. You can, however, use a dual GL-4/GL-5 gear oil in your gear box if you wish, as it won't harm yellow metals.

View attachment 223897

Would you take a quick look at the link below where they mention it's safe for yellow parts and tell me what you think about that if you get time?

Gear Competition 75W140

PART NUMBER: 105779 TYPE OF USE Specially designed for racing vehicle gearboxes : speed way, rally, raid… All hypoid differentials with limited slip system (LS or LSD), gearbox with integrated limited slip differential, mechanical transmission, synchronized or not synchronized gearboxes...

motul.speclube.com

Link

 

[The Lube Guy]

Would you take a quick look at the link below where they mention it's safe for yellow parts and tell me what you think about that if you get time?

Gear Competition 75W140

PART NUMBER: 105779 TYPE OF USE Specially designed for racing vehicle gearboxes : speed way, rally, raid… All hypoid differentials with limited slip system (LS or LSD), gearbox with integrated limited slip differential, mechanical transmission, synchronized or not synchronized gearboxes...

motul.speclube.com

Link

That's the exact same oil I got in the rear diff in my 2022 Jeep GC WK2. Motul makes very good gear oil, but don't use that particular gear oil in applications that call for GL-4.

If you need a GL-4 compatible 75W-140, look at Red Line 75W-140NS.

 

[fbdewar]

Just wondering why it says it's suitable for yellow material?

 

[The Lube Guy]

Just wondering why it says it's suitable for yellow material?

I saw that, it even says it on Motul's PDS sheet. I'm just playing it safe. I'd rather not give you bad advice.

What type of vehicle and gearbox is it? What does it call for?

 

[fbdewar]

I saw that, it even says it on Motul's PDS sheet. I'm just playing it safe. I'd rather not give you bad advice.

What type of vehicle and gearbox is it? What does it call for?

No I appreciate it. I'll look at that redline you recommended.
It's 75W90 but I'm looking for something a bit thicker to try and alleviate some notchiness and poor shifting issues. Just hoping ford specs thinner fluid to meet mpg requirements.

 

[The Lube Guy]

No I appreciate it. I'll look at that redline you recommended.
It's 75W90 but I'm looking for something a bit thicker to try and alleviate some notchiness and poor shifting issues. Just hoping ford specs thinner fluid to meet mpg requirements.

Motul Gear 300 75W-90 is what you want. The 75W-140 is too thick even for semi-truck gearboxes, let alone a car. Give Motul a try, it should work fine. It's good stuff.

 

[fbdewar]

Motul Gear 300 75W-90 is what you want. The 75W-140 is too thick even for semi-truck gearboxes, let alone a car. Give Motul a try, it should work fine. It's good stuff.

Using 300 now that's what I'm switching from.
Tried so far-
Ford OEM DCTF
Pentosin FFL4
BG Synchroshift 2
BG Synchroshift 2 and Ceretec
Motul Gear 300

Two cars with the same ****ty getrag transmission shifting the same. Just trying to find a fluid to band aid the issues as much as possible.

The cold rating is still 75W so viscosity wise wouldn't it be ok at least at room temp? Just wouldn't thin out as much at operating temp?

 

[Jetronic]

Using 300 now that's what I'm switching from.
Tried so far-
Ford OEM DCTF
Pentosin FFL4
BG Synchroshift 2
BG Synchroshift 2 and Ceretec
Motul Gear 300

Two cars with the same ****ty getrag transmission shifting the same. Just trying to find a fluid to band aid the issues as much as possible.

The cold rating is still 75W so viscosity wise wouldn't it be ok at least at room temp? Just wouldn't thin out as much at operating temp?

No, at room temperature they are like the hot rating, If you get notchy shifting, especially if it improves when the car has been driving a bit, the answer is a thinner fluid, to help the synchroniser do their work.

The 75W part of the spec is not really relevant, there's no thinner spec. But a lot of fluids list the brookfield viscosity in their spec sheet, look for a lower viscosity there without sacrificing hot viscosity

 

[fbdewar]

No, at room temperature they are like the hot rating, If you get notchy shifting, especially if it improves when the car has been driving a bit, the answer is a thinner fluid, to help the synchroniser do their work.

The 75W part of the spec is not really relevant, there's no thinner spec. But a lot of fluids list the brookfield viscosity in their spec sheet, look for a lower viscosity there without sacrificing hot viscosity

It's not an issue when cold. Synchro engagement at higher rpm is poor Swapped a new transmission in under warranty. Same issue.
BG with Ceretec has been the best so far.

 

[Jetronic]

It's not an issue when cold. Synchro engagement at higher rpm is poor Swapped a new transmission in under warranty. Same issue.
BG with Ceretec has been the best so far.

That also points to too high viscosity, the high rpm difference keeps an oil film between the synchro parts.

 

[The Lube Guy]

Using 300 now that's what I'm switching from.
Tried so far-
Ford OEM DCTF
Pentosin FFL4
BG Synchroshift 2
BG Synchroshift 2 and Ceretec
Motul Gear 300

Two cars with the same ****ty getrag transmission shifting the same. Just trying to find a fluid to band aid the issues as much as possible.

The cold rating is still 75W so viscosity wise wouldn't it be ok at least at room temp? Just wouldn't thin out as much at operating temp?

Gear oil is different from motor oil in how it's tested for cold flow. To put it in simple terms, it has to flow at cold temperatures to get the same rating. 75W-140 is too thick for a manual transmission.

You need to try either Red Line MT-LV or an ATF. However, I'd like to know first what kind of transmission it is, and what the owner's manual recommends.

If you put 75W-140, you will get worse shifting, especially when it's cold.

Edit:
I wouldn't run 75W-140 even in a transmission without synchronizers, like an Eaton-Fuller 13 or 18 speed. For example, these transmissions call for SAE 50 manual transmission oil.

For example, the Tremec 56, used by Ford, Dodge, etc. in their cars, called for SAE 50 manual transmission oil. Chrysler, when installed in their vehicles, recommended ATF+ 4, to improve shift feel.

Going thicker is almost never the answer.

 

[fbdewar]

Was thinking I'm going to give redline DCTF a try. I'll check the MTLV also.
It's for a Ford IB6 with a wavetrac LSD.
Thank you both for the input I appreciate it and apologize for my lack of knowledge.
Elsewhere in the forums it mentioned if you were having synchronizer issues usually a thicker less slippery fluid will help with engagement which led me down this path and since I have an LSD I thought it needed additive but have since found that's only for clutch pack style LSDs.
The fact that it worked better with BG with Ceretec which is lower viscosity than Gear 300 but higher than FFL 4 which was worse has left me confused.
How slippery a fluid is, is a function of viscosity and.... additive package?
The OEM fluid was terrible but there were reports of underfill from factory so maybe the issue was just underfill from the get go and I've been trying other fluids for no reason.

 

[Jetronic]

DCT fluid is in a way like JASO MA2 fluid for shared sump systems: it needs to have a sufficiently high friction for the clutches to work (so careful selection of, or lack of friction modifiers), and I have found it tends to work well for synchros.

So DSG/DCT fluid can definitely be a good candidate to improve shifting, it would also help the wavetrac.

 

[fbdewar]

DCT fluid is in a way like JASO MA2 fluid for shared sump systems: it needs to have a sufficiently high friction for the clutches to work (so careful selection of, or lack of friction modifiers), and I have found it tends to work well for synchros.

So DSG/DCT fluid can definitely be a good candidate to improve shifting, it would also help the wavetrac.

It's a manual 6speed that calls for DCTF.
Lots of others report success with gear 300. Not my experience unfortunately.

 

[Jetronic]

Look for a wet clutch MTF like vw DSG, they also have a low viscosity variant.

 

[fbdewar]

Look for a wet clutch MTF like vw DSG, they also have a low viscosity variant.

Ok mine is a dry clutch. Does that matter?

 

[Jetronic]

Ok mine is a dry clutch. Does that matter?

No, for wet clutches means less slippery.