Mercedes manual gearbox oil confusion

[OM605]

Hi everyone,

When i got my 1998 Mercedes W202 with 128 000 kms i found the shifts to be really hard and slow when cold (1st, 2nd and reverse) so i went ahead and changed the oil with some MB 235.10 75W80 (i think it was the factory fill and what was in there) and that did not really cure the issue.

I just replaced the oil again 4 months and 15 000 kms later with some MB 236.6 ATF and it's like night and day when cold but harder to shift when hot.

What i dont understand is that fot the 717.4 transmission the specified fluid is ATF up to serial n° 7 340 240 and then 75W80 starting at serial n° 7 340 241 (mine).

What did they change in the transmission itself to recommend gear oil instead of ATF ? What am i risking ? I vaguely remember talking about this issue with a mechanic at the MB dealer and he told me they would fill transmissions with ATF if customers complained about shifting problems when cold, even on more recent 6 speed gearboxes.

I'm thinking about trying other 75W80 gear oils since i am not satisfied with the way it feels when hot, what would you recommend ? I'm not going to stick to MB 235.10 approved oils since there's only 2 or 3 oils available. I can get my hands on Total Gear 8, Motul Motylgear, Castrol Syntrans, Shell Spirax, Fuchs Titan Sintofluid...

Should i avoid GL-5 for shifting comfort ?

 

[Pelican]

If you can try to look at LiquiMoly Manual Transmission Oil, it will have all the specs on the bottle.
They generally have very good stuff for MB

 

[tundraotto]

Are the MB 235.10 approved oils GL-4 or GL-5, or both?

 

[barryh]

I know for the NSG270 manual boxes like mine MB specify a thinner oil MB235.3 as an option. It's described as "ServiceKit for cold shiftability"

One of these approved oils is Syntrans FE MB235.3. The viscosity specs for the Syntrans FE 75W that I can find are 6.3cSt @ 100 Deg C and 32.2 cSt at 40 Deg C

So it's thin stuff similar to ATF but it would have the right friction modifiers for a manual box. To get these friction modifiers you want a proper manual transmission oil rather than a general GL-5 gear oil intended for diffs. In any case I doubt that these thin gear oils would be GL-5.

 

[OM605]

Thank you barryh for the advice. The 75W oils seem very interesting indeed as they have the viscosity of a thin ATF. Are they as good as 75W80 for shifting when hot ? I am associating the poor shifting when hot with the slightly lower viscosity of ATF, something that make synchros act weird.

tundraotto, most MB 235.10 are GL-4, some are GL-5 too.

 

[tundraotto]

RedLine MT-90 works great for me in a Toyota W150 manual transmission, but understand may not be available there....

MOTUL has not disappointed me in anything I have ever used it in...

 

[barryh]

I haven't tried the Syntrans 75W yet but have it in mind to do a routine maintenance change as my car will almost certainly be on it's factory fill oil at 68,000 miles.

 

[tundraotto]

It seems the MB 235.10 approved oils are/is:

75W-85

https://bevo.mercedes-benz.com/bevo...e_id=1&blatt=235.10&suchbegriff=

 

[MolaKule]

Originally Posted by M119
Hi everyone,

When i got my 1998 Mercedes W202 with 128 000 kms i found the shifts to be really hard and slow when cold (1st, 2nd and reverse) so i went ahead and changed the oil with some MB 235.10 75W80 (i think it was the factory fill and what was in there) and that did not really cure the issue.

I just replaced the oil again 4 months and 15 000 kms later with some MB 236.6 ATF and it's like night and day when cold but harder to shift when hot.

What i dont understand is that fot the 717.4 transmission the specified fluid is ATF up to serial n° 7 340 240 and then 75W80 starting at serial n° 7 340 241 (mine).

What did they change in the transmission itself to recommend gear oil instead of ATF ? What am i risking ? I vaguely remember talking about this issue with a mechanic at the MB dealer and he told me they would fill transmissions with ATF if customers complained about shifting problems when cold, even on more recent 6 speed gearboxes.

I'm thinking about trying other 75W80 gear oils since i am not satisfied with the way it feels when hot, what would you recommend ? I'm not going to stick to MB 235.10 approved oils since there's only 2 or 3 oils available. I can get my hands on Total Gear 8, Motul Motylgear, Castrol Syntrans, Shell Spirax, Fuchs Titan Sintofluid...

Should i avoid GL-5 for shifting comfort ?


If the tranny uses an ATF then a MTF such as:

https://www.redlineoil.com/Content/files/tech/MT-LV_GO_PROD_INFO(1).pdf

should provide better shifting and additional anti-wear protection.

 

[OM605]

My first choice would be a Redline product such as MTL, MT-LV or D4 ATF but they are not sold where i live or if they are it's like 30€ for a one quart bottle. I might try Motul Motylgear 75W80 this week and then Castrol Syntrans 75W later if i'm not satisfied and report back.

 

[OM605]

It's been almost almost a month now but i drained the ATF and put some Febi 75W 235.10, looks like it is the best oil so far, a little bit harder than the ATF when cold the but the smoothest of all when hot.

From worst to best so far :

- 75W80 GL4/GL5 235.10 : Always hard and notchy.
- ATF 236.6 : Easy when cold but slightly notchy when hot.
- 75W GL4 235.10 : A bit harder when cold but smooth when hot.

I think i should stick to the 75W oil for now and GL4 instead of GL4/GL5 might have something to do with the smoother feel and better synchro engagement.

 

[AC1DD]

Originally Posted by M119
I

I think i should stick to the 75W oil for now and GL4 instead of GL4/GL5 might have something to do with the smoother feel and better synchro engagement.


This GL-4 is critical for smooth operation of synchronized manual gear boxes unless there is a combined differential and manual gear box where they share oil,
NEVER use GL4-5, GL-4+, GL4/5, ect ONLY USE A GL-4 SPEC OIL IN THAT GEARBOX

 

[OM605]

I dont understand why MB 235.10 oils are all over the place, both in viscosities and API specs. Totally discredits it in my opinion and i dont feel like paying attention and sticking to MB approved fluids only as i was before. At least for the manual transmission / Rear diff.

By the way, what is GL4+ ? I see a lot of oils with that spec.

 

[kschachn]

Originally Posted by M119
I dont understand why MB 235.10 oils are all over the place, both in viscosities and API specs. Totally discredits it in my opinion and i dont feel like paying attention and sticking to MB approved fluids only as i was before. At least for the manual transmission / Rear diff.

Both are irrelevant if the lubricant is approved. Besides, how many actual approved lubricants are there for 235.10?

 

[OM605]

I found a few, Vaico 75W80 GL4/GL5 (which i had), Ravenol 75W80 GL4, Mannol 75W80 GL4, Febi 75W GL4 (what i have at the moment), Mobil 317 which i believe is a 75W GL4 and the 235.10 oils available at the dealer but the bottles dont tell anything other than a part number.

 

[kschachn]

I don't believe any of those have 235.10 approval, do they? That was the point I was trying to make, that you see different API licenses and different grades because as far as I know everything on that list is recommended, not approved. It doesn't make it unsuitable however, especially for this particular approval.

 

[OM605]

Those are the only 235.10 oils i found. Good luck finding where to buy them, even on the internet. Same story with the 235.7 approval for diff oils. I recently asked an independant mechanic who's been working on MBs cars and big trucks for a long time and he just told me "GL4 in your transmission, not heavier than 75W80 and GL5 in your diff, 75W80 or 80W90, every 60 000 kms for peace of mind) And he did not seem partial to sticking to the MB approvals like he did when i asked about other stuff like power steering, coolant or automatic transmission.

 

[AC1DD]

Originally Posted by M119


By the way, what is GL4+ ? I see a lot of oils with that spec.


Essentially it is a fluid that meets GL-5 requirements while also meeting those of GL-4, except time and time again it's been proven in the real world that
the extra EP additives cause lower quality shifting with manual synchronized gear boxes on most passenger vehicles.

The only thing you should use in synchronized manual gear boxes is GL-4 (except when the box shares fluid with a differential like in a Subaru.) that's a rare exception.

 

[Donald]

I am a lot older than most, but as long as the transmission shifts properly in my truck I am happy. I don't need a sporty feel.

I had the sporty feel in my 1969 Mach 1 Mustang w/351W back in the 1970s.

 

[OM605]

Originally Posted by Donald
I am a lot older than most, but as long as the transmission shifts properly in my truck I am happy. I don't need a sporty feel.

I had the sporty feel in my 1969 Mach 1 Mustang w/351W back in the 1970s.


I guess we're light years from sportive with older Mercedes manual transmissions.