Using Liqui Moly Ceratec in Manual Gearbox

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If you know how a M/T gearbox synchro works (works by proper coefficient of friction of the fluid), you'd definitely refrain from adding anything into your M/T gearbox that would alter the coefficient of friction in your gear lube), especially those that claimed "friction reducing" or similar.

Q.
 
Originally Posted By: Johnyjj1212
I was wondering what the benefits are of doing so, and if it can cause any problem with brass synchros.

Anyone have a clue?

http://www.liquimoly.co.uk/index.php?p=product_details&id=2

http://www.liquimoly.co.uk/assets/pdf/safety/2.pdf

http://tinyurl.com/bmhs5ll


UMM! LM are a good company, but I don't think too many gearbox manufacturers approve additives of any kind, ALSO Ceretec contains a fair dose of Moly. Adding anything other than top up oil to gearbox oil is asking for real trouble as regards seals and synchros. If you have an old gearbox changing the oil is worth doing, but nothing else apart from approved oil should be used.
 
Thank you for your insight, guys.

I've found this forum post (another forum) that talks about using moly and what else in manual gearboxes (the poster actually has the same gearbox as I do - a Renault JB manual gearbox). Do you think he has a point? Or is adding it to the oil always a no no?

I ask because I could really use some smoother shifting (very clunky when cold) and new gear oil did not solve it.

Here's the post I'm speaking of:

Quote:
Now about the additive. Basically the same people (most of them on bobistheoilguy.com website) told me that MoS2 or virtually any other friction reducer additive should be banned in synchromesh gearboxes because for proper operations, synchros need frictions....which is true. So many of these people told me that using MoS2 in the box would make the snychro slip too much and prevent good meshing of the gears. After discussing this issue ith Liqui-Moly, I was told that this was correct theoretically but it depends on the dosage of MoS2 in the gearoil...obviously! LM advises to use something like 2% additivation only. This is enough to reduce friction on the gears and bearings but synchros would need much more to be affected. All I can say is that after 50'000km on this additive in the box, the synchros work just perfectly and the box is smoother.....so all the warnings I got (which perfectly make sense on a theoretical basis) were not funded here. On the first application I was very conservative and went with less than 1% additivation. Now I just renew the gearoil and went to the recommended 2%: absolutely no problem with synchros. In fac it is explainable: MoS2 is a friction reducer but only when metal-metal contact occur (basically MoS2 prevents metal to metal contact). However synchros work on the actual friction of the oil itself...and this is not modified with a 2% additivation. So with this additivation you get the benefit to reduce wear when metal-metal contact would have occured (like in ball bearing or gears etc) but synchros are not affected because they work with the friction of the oil and not the friction between 2 metalic surfaces (I'm unsure if what I say is clear, please tell me).
 
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Originally Posted By: Johnyjj1212
I ask because I could really use some smoother shifting (very clunky when cold) and new gear oil did not solve it.

Sounds like you are using an oil with a low VI or simply too heavy. What fluid was the oil and the new?

What is the car / transmission this is being used in?
 
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Moly would be great in a 'crash box' with no synchros.
Also, very good for many parts in a trans WITH synchros.
BUT... horrid for synchros, because they would slip, not grab. Maybe with aggressive synchro facings, we could get away with it.

It is not worth taking a chance!
 
Originally Posted By: martinq
Originally Posted By: Johnyjj1212
I ask because I could really use some smoother shifting (very clunky when cold) and new gear oil did not solve it.

Sounds like you are using an oil with a low VI or simply too heavy. What fluid was the oil and the new?

What is the car / transmission this is being used in?


The car is a Renault Laguna 1.8 liter, 1997.
Gearbox is a Renault JB3.

The fluid was the factory spec and the new fluid was also the factory spec (Elf NFJ 75W80 GL4+)
 
Originally Posted By: mechtech2
Moly would be great in a 'crash box' with no synchros.
Also, very good for many parts in a trans WITH synchros.
BUT... horrid for synchros, because they would slip, not grab. Maybe with aggressive synchro facings, we could get away with it.

It is not worth taking a chance!


So, you think that even in the dosage indicated by that post I quoted it would be bad for the synchros?

Correct me if I'm wrong: The moly would not attack the synchros per se but only make them not work well because of the not enough friction in the oil?
 
Originally Posted By: Johnyjj1212
The car is a Renault Laguna 1.8 liter, 1997.
Gearbox is a Renault JB3. The fluid was the factory spec and the new fluid was also the factory spec (Elf NFJ 75W80 GL4+)

Is this the first fluid change and how many km are on it?

You could try something in a 70w80 that's designed as a MTF. Are there any GM (or related) dealers in your area? You could look for GM Synchromesh or Pennzoil Synchromesh. There are also known-good oils from Red Line, Amsoil and several others but it depends on what is available in your area.

'Very clunky when cold' tells me that the syncros are having trouble and this is due to either viscosity (too thick) or the lack of proper FM (friction modifiers).

It's possible that a certain amount of additive may improve the action of the gearbox but I doubt it'll improve the synchro action.

I found a spec sheet which shows:
47 mm2/s @ 40C
8.5 mm2/s @ 100C
175 VI
-40C Pour Point
 
1% additive is 10,000 ppm, but the additive is not 100% moly

i guess LM can say 2% because they know the ppm of their formula but it's still a craapshoot. the good news is you can change it out if you find synchro misbehavior
 
Originally Posted By: Johnyjj1212

Correct me if I'm wrong: The moly would not attack the synchros per se but only make them not work well because of the not enough friction in the oil?


Yes, this is not a matter of additives attacking your synchros (bronze alloy) but more like altering the friction necessary for proper gear engagement (the proper slippage required to minimize crashing).

Q.
 
Originally Posted By: mechtech2
Moly would be great in a 'crash box' with no synchros.
Also, very good for many parts in a trans WITH synchros.
BUT... horrid for synchros, because they would slip, not grab. Maybe with aggressive synchro facings, we could get away with it.

It is not worth taking a chance!


I just added cera-tec to my engine yesterday. It was a creamy pinkish colour. Liqui-moly is black. So I am going to go out on a limb here and say there isn't any molybdenum disulfide in the cera-Tec additive.
I'm not saying there isn't some other type of moly in the cera-tec but I'm confident that there is not any molybdenum disulfide in it.
 
Originally Posted By: Johnyjj1212
Originally Posted By: mechtech2
Moly would be great in a 'crash box' with no synchros.
Also, very good for many parts in a trans WITH synchros.
BUT... horrid for synchros, because they would slip, not grab. Maybe with aggressive synchro facings, we could get away with it.

It is not worth taking a chance!


So, you think that even in the dosage indicated by that post I quoted it would be bad for the synchros?

Correct me if I'm wrong: The moly would not attack the synchros per se but only make them not work well because of the not enough friction in the oil?


Right - the moly is not corrosive. It makes the synchros slip, which is great for making things grind and balk when you shift.
Is a little OK? It's not worth the chance! Really.
I'd love to use moly in transmissions and transaxles, but the deal killer is not being able to shift right.
Let's avoid it and use the best gear oil we can get.
 
Quote:
This is enough to reduce friction on the gears and bearings but synchros would need much more to be affected. All I can say is that after 50'000km on this additive in the box, the synchros work just perfectly and the box is smoother.....so all the warnings I got (which perfectly make sense on a theoretical basis) were not funded here. On the first application I was very conservative and went with less than 1% additivation. Now I just renew the gearoil and went to the recommended 2%: absolutely no problem with synchros. In fac it is explainable: MoS2 is a friction reducer but only when metal-metal contact occur (basically MoS2 prevents metal to metal contact). However synchros work on the actual friction of the oil itself...and this is not modified with a 2% additivation. So with this additivation you get the benefit to reduce wear when metal-metal contact would have occured (like in ball bearing or gears etc) but synchros are not affected because they work with the friction of the oil and not the friction between 2 metalic surfaces (I'm unsure if what I say is clear, please tell me).



Wrong in so many ways!

You guys really need to read the White papers etc.
 
Originally Posted By: Carmudgeon
LM has a product designed for gearboxes:

http://www.liquimoly.co.uk/index.php?p=product_details&id=11

It's basically moly in a carrier oil. Very dark black.

Why would you use another product meant for engine crankcases?



LM states that ceratec can be used in both the engine and transmssions. Ceratec, I think, has both moly and ceramic compound.
 
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Originally Posted By: MolaKule
Quote:
This is enough to reduce friction on the gears and bearings but synchros would need much more to be affected. All I can say is that after 50'000km on this additive in the box, the synchros work just perfectly and the box is smoother.....so all the warnings I got (which perfectly make sense on a theoretical basis) were not funded here. On the first application I was very conservative and went with less than 1% additivation. Now I just renew the gearoil and went to the recommended 2%: absolutely no problem with synchros. In fac it is explainable: MoS2 is a friction reducer but only when metal-metal contact occur (basically MoS2 prevents metal to metal contact). However synchros work on the actual friction of the oil itself...and this is not modified with a 2% additivation. So with this additivation you get the benefit to reduce wear when metal-metal contact would have occured (like in ball bearing or gears etc) but synchros are not affected because they work with the friction of the oil and not the friction between 2 metalic surfaces (I'm unsure if what I say is clear, please tell me).



Wrong in so many ways!

You guys really need to read the White papers etc.


Please continue. You are saying that any moly in the manual gear oil will wreck havoc?
 
Ok, guys, since moly is not corrosive for the synchros and the worst that can happen is that I need to change the oil in the gearbox for fresh one I used ceratec in my gearbox oil.

I would estimate I used the equivalent to about 1% of the gear oil.

I've done a 250km journey today with it.

First impressions: 1st and 2nd gear go in smoother when cold than before (3 C - 37 Fahrenheit here right now).
No problem whatsoever with the synchros. I did not hear any kind of grinding in any gear and I usually hear some grinding occasionaly (or did, before adding ceratec).
 
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An application specific Manual Transmission fluid like Synchromax, Pennzoil Synchromesh, GM MT, Redline MT, Amsoil MT, etc, has a friction modifier in it to allow proper coefficient of friction for engagement/disengagement.

Moly is a friction modifier than can COMPETE with the friction modifier's in an MT.

Moly won't kill it, but it is not the optimum friction modifier for a Manual Transmission lubricant.


https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2813713#Post2813713
 
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Quote:
Quote:
However synchros work on the actual friction of the oil itself...




Not true. See explanation above.
 
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