I've just been on a trip in my Roadster and apart from getting a surprisingly good over 30mpg, I also noticed that the gear change gets better the further you go - presumably as the oil in the box heats up. Just wondered if anyone has changed it for anything better as most of my journeys are about 10 miles not 200, and if they have is it hard to do?

 

I have changed out the fluid, but only with more OEM fluid because of the miles. If you are over 50K, I would recommend it, as it made my shifts a little crisper.

There have been several members with low mileage cars that have changed it as well for something like royal purple or amsoil equivalent. They report similar results of better shifting.

The drain plug is a little difficult to get to, and is a strange size, but it is a pretty straightforward process.

Good luck.

 

https://www.crossfireforum.org/forum...laination.html

End of story....I wound up keeping the 0w20 synthetic motor oil in it. It's still notchy, but there really is no better lubricant (more slippery) that you can put into your gear box to make it shift any smoother.

 

Just wondered if anyone had tried a different spec as it would seem that if the change gets better when its warmer then thinner would be better?

 

They spec that fluid for a reason and a team of MB engineers knows a lot more than I do about the inner workings of the tranny and fuid dymanics. I am sure you could get something else, but if it is a year round driver, I would stick with what MB recommends.

 

They may know what to put in their own gearbox but they wouldn't know how to make a decent manual box to save their lives if this one is anything to go by
Just thought I'd ask

 

amtrying to find the place where the filling and drain plugs are at the crossfire manual transmission.
any leads?
thanks

 

Do not drain the manual tranny until you can loosen the fill plug. Here is a tool for that hard to get to fill plug ebay https://www.ebay.com/itm/CTA-Jeep-6-...72.m2749.l2649

 

thank you for the lead. this seems to be a 14mm hex to 3/4 . as i understand it, the plug is 14mm, and the other end is 3/4. but, why 3/4? could it be 1/2?
i ask because i dont have 3/4 wrench.
something like this: https://www.homedepot.com/p/GEARWREN...0662/204617131
but why looks so different ?

 

Hello,

If you can not find any tool, I suggest you welding a nut into a bolt and use an wrench. It is easier than find te required tool. Those hex tools are quite big, you will need a 14mm for the fill plug, and 17mm for the drain plug.
When I did this on my 270.000 miles Xfire, I filled it with Febi 75w, very important fill it with MB 235.10 GL4 oil.
In my case, I used Febi Bilstein. According to R170 service manual by Mercedes Benz, 75w85 should be used, with 1,5 liters. I filled with about 2 liters because at 1,5 gears weren´t smooth enough.

 

thank you for the input. good to know also that the drain is 17mm. will work from that to fit my tools.
on the search i found several options. i just was intrigued by the difference in shapes and what goes at the other end of the 14mm hex.
i conclude that what goes at the other end is what fits your equipment best.
i find hard to believe that there is no data available (to my knowledge) about the sizes and location, even if i searched extensively.
eventually i found a drawing showing the location, so with that and the sizes of both plugs i can do.
still, with so many thousands of xf with manual transmissions around, this basic data should be easily available for us who do work on our cars. especially something so simple as changing transmission oil.
once again, thank you for the data on the 17mm.

 

Be calm, its quite easy to find it.
When you stand the car, the drain plug is a very big hex bolt at the bottom and center of the gearbox. Quite easy to find.
The fill plug is in the passenger side (right side of the vehicle) and you will need a pump or a syringe to fill it, because it is in a not at a suitable position, you should know this before doing the job haha.
On this link you can find all the information (for sure, on this forum too but this link is on my browser bookmarks). If you replace the oil, think about changing the rear differential. It is 1 liter, with 2 14mm hex bolt, as the fill plug of the gearbox, and you should use 235.7 MB Spec, 1 liter.
I did it a few months ago, the rear diff oil was black, new was red-pink.

 

great pic and data. thank you very much.

 

You can use a 19 mm box end wrench instead of a 3/4" the tool with the wrench is only 1 1/4" in depth and is easier to get in a tight place: https://www.ebay.com/itm/CTA-Jeep-6-...72.m2749.l2649

 

Viscosities mentioned in this post are pretty far apart ?? 0-20 & 75 ? From my 60 some yrs experience w/ transmissions , 75 seems more applicable but then todays lubricants are nothing like yesterdays for basically the same mechanical mechanism --- but---- w/ todays ability to hold tighter machining tolerances along w/ very high bearing quality leads me to suspect a much finer , closer tolerance mechanism not requiring the heavier viscosities of days gone by .

 

Sae for motor oil is different than transmission oils.
I read on this forum people use 5w20 motor oil as gearbox oil but thats not for me, i will never use engine oil on a gearbox.

As you can see on this pic, motor oil and gears oil is not the same SAE scale
https://syntheticwarehouse.net/wp-co...ositychart.jpg


For sure, the original oil for this gearboxes used in service operations at MB Dealer is 75w85 GL4, MB235.10
Any other oil is not the best option for this gearbox.
In my case with Febi 75w gl4 mb235.10 (instead 75w85) the smooth is great, and gearbox seems to be perfect

 

the manual specifies for:
1-the engine: only synthetic engine oils approved to MB 229.3 or MB 229.5, such as Mobil 1 SAE 0W-40 (notice that here it calls engine oils.)
2-automatic transmission: only use ATF approved to MB 236.10, MB 236.12 synthetic dextro III transmission fluid may be substituted. (here says transmission fluid. never says oil).
3-manual transmission fluid: only use fluid approved to MB 236.2. SAE 5W-20 engine oil, meeting API SL or GF-3, may be substituted. (here is fluid-and engine oil). so manual uses oil..
4-rear axle fluid: only synthetic SAE 75W85 axle lubricant that meets MB 231.1 (here is called lubricant)
so, which is oil and which is not? and rear axle takes lubricant, so does not say oil.
so, which has to go with which SAE? there is no mention on which.
and the manual is the bible.
i must add that am not criticizing anything. neither am attacking or defending anything. just trying to understand what is what and therefore reach conclusions and act accordingly.

 

I would not say that.
I have documents from official MB dealer (a friend here in spain) and he gave me the specs for 716 gearbox, used in xfire and slk320.

If you tale a look at some internet website oil, like mobil, you can see the required specs.
Also, tomorrow i will post here the documents

 

I have not seen an oil that is not a fluid.

Where an oil gets thick enough to be called a grease I have no idea, or is there something in grease that defines it as a grease.

Item 4 says ‘rear axle fluid’ so it is an oil.

Oils and greases are lubricants, greases are not used in any of the four components listed.

 

that will be great. then we may analyse it and perhaps reach the bottom of the issue. what matters is that we have to understand what the manufacturer intended to say.
as always, communications is a tough cookie.
and wonder what you mean regarding "i would not say that"? that what? please specify. (perhaps you refer to:" which has to go with which SAE?"?)