Question about synthetic gear oil. Has anyone switched to try to make the shifts smoother? All the reviews I can find (mostly end users) talk about smoother shifting and less noise. When I look up the 6-speed in our XF's it says

The NSG370 does not use standard gear oil for lubrication. This transmission utilizes bronze synchronizer collars resulting in sensitivity to lubricant make-up. Only a fluid characterized by Chrysler specification MS-9224 should be used in order to avoid premature wear or failure of internal parts as well as voiding the factory warranty.
Common synthetic alternatives to the factory Mopar-branded conventional lubricant are Royal Purple Synchromax and Red Line Oil's MTL. The synthetic alternatives often improve shifting performance while decreasing internal wear and noise.

http://www.redlineoil.com/product.aspx?pid=45&pcid=7

http://www.royalpurpleconsumer.com/p...mission-fluid/

When I go to Royal purple's and Red Lines sites it says they have approved replacement synthetics. They both talk about it's safe for brass or bronze synchronizers.

Royal Purple Chrysler MS9224 = Synchromax
Red Line Chrysler MS9224 = MTL 75W80 GL-4 Gear Oil

 

Any answer to this? I am tired of the clunky shifts too.

From what I have read, MTL 75W80 GL-4 Gear Oil seems like the correct oil.

 

Many of us tried Mobile 1 5W20 and loved it. I put it in my last car and drove it from 60-some thousand miles to 116,000 on 5W20.

John (BoilerupXfire) is the one who suggested it to me. My car shifted better after putting it in - of course, by the time it had 100,000 miles on it, it shifted way better - what these cars' transmissions need is MILES!!!

Change your differential fluid while you are at it - I would need to go look, but I think it was 75W80 we used - Mobile 1, of course.

 

OH MY LAWD! 75W80? That is fine for the differential, but don't put that in your transmission!

That can't be right......

 

See this recent thread for more info:

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

 

Your post:
Quick update - Changed the tranny fluid today to Amsoil 5W-30 MTL Synchromesh with very good results. 1st / 2nd gear shifts are improved, and all gear changes seem crisper. (Although I'm sure there's a little placebo effect going on).
Think that this is as good as this MB tranny will get, and will check back in if anything changes.
Again, I appreciate all of your input on this topic.

Good enough for me!

 

NSG370 transmission is in all Crossfires or only in USA versions?
I have EU 6-manual speed version and want change oil in gear box.
What I need? 5W20, 5W30 or 75W80, 75W90 ?
Normaly almost EU cars use 75W80 or 90 gear oil.

 

Trust me...go with MB manual gearbox oil spec 235.10. I've tried 'em all, and this stuff is the real deal. You can get it from Needswings. See my post from last week below.

https://www.crossfireforum.org/forum...tml#post874238

 

235.10 it's 75W80 ?

 

Yep, and I believe it's a semi-synthetic. It really improved my car's shifting characteristics.
Penrite also makes a 75W80 that meets the 235.10 spec, but the MB fluid is amazing.

 

Ok, thanx.
I let you know after oil change.

 

Really? John T and John M suggested Mobile 1 5W20 -that's what I put in the Graphite Roadster.

Did not make a HUGE difference, but it was smoother entering any gear.

 

I think 75W80 is similar 5W20

 

Cappacity 1.8L for gear box and 0.8L for differential? Correct?

 

Make that 1.3L for the diff.
I just pump fluid in the trans and diff until it runs out of the fill hole when the vehicle is level.

Also, your viscosity chart is great. We're looking for a trans fluid with a kinematic viscosity of around 10ish at 100*celsius.

 

Thanx.
Harbor I see that you want do the same like me (I want change thermostat, gasoline filter next month).

 

I change gear oil for Liqui Moly 75W80. This was not good idea, gears was hard on cold engine.
I talk with Chrysler specialist and he say that for gear box NSG370 we can use only oil with specification MS-9224. For differential in good condition 75W90 full synthetic, for old and tired diff 85W90.
I change gear oil again for RAVENOL STF SYNCHROMESH TRANSMISSION FLUID and now is OK.

 

I changed third time oil in gear box. Now I used Mercedes oil 235.10. A001989840309
Harbor you had right -this oil is the best!

 

kamil - Glad it worked out. Motor oil just doesn’t belong in a tranny. The MB gear oil is pricey, but well worth it.
By the way, I think you are the only forum member who’s ever followed my advice - Ha!
Take care.

 

Well not the only one, I just picked some up from my local Mercedes dealership and will be changing out mine this week. It was a little cheaper than needswings price after shipping and hopefully it will help with 1st and 2nd gear.

I looked hard but could not find any other MB 235.10 spec oil in the U.S.

Motul, Castrol and a few other brands do make them, they just are not readily available here and after shipping it costs more than the Benz oil.