Manual Tranny Fluid for Cold Weather

[Blue_Angel]

I have a 2012 Chevy Cruze with a manual transmission. Many members on one of the Cruze forums have changed their transmission fluid to Amsoil Synchromesh and reported positive results (mostly improved shifting, less grinding on hard shifts). Along with a concern over inconsistent factory fill volume (incorrectly filled transmissions from the factory) I decided to follow their lead and change my OE fluid out for the Amsoil Synchromesh.

After driving for a few days now I can say the transmission does shift smoother than before, however...

This morning was pretty cold here in Ottawa, -26C (-15F). First shift this morning into reverse went smooth, smoother than it ever was with the OE fluid at this temperature. Once out on the street, 1st was very difficult to engage and the transmission fought me going into 2nd and 3rd as well just driving very slowly up my street. After a few minutes of driving shifting improved significantly.

The transmission has never before fought me all the way up into 3rd gear like that before with the OE fluid. It was a little stiffer than normal when this cold out, but never actually hard to get into gear.

The clutch was working fine. The clutch hydraulics in this car seem pretty much unaffected by temps down to about -30C (-22F), at which point it begins to feel a little stiff. This morning it was working perfectly fine.

So after two days of driving my impressions of the Amsoil Synchromesh are, better when warm, worse when extremely cold (~-25C, ~-13F), in this application at least. It is possible the transmission will improve as the Amsoil works into the tranny's bits, but I would think after several days of driving it's mostly there already.

Are there any manual transmission fluids (synchromesh?) that are known to work better at low temperatures? Do others have different experiences with this fluid at these temps?

 

[ARCOgraphite]

Ive found new fluid to be balky for a few weeks right after its been changed out. Is the syncromesh a 75w or lighter? Pennzoil sync is grade equivalent to a light 5w20 oil, IIRC. What is the chevy MT fluid spec?

 

[Lead Shoes]

I feel you... I can't seem to find a MTF that makes the trans feel butter smooth when temps dip below 0...

 

[aquariuscsm]

I`d rather have better hot shiftability,because you can always baby it till it warms up,but you don`t want it too thin once good and hot.

 

[dparm]

Originally Posted By: Brenden
I feel you... I can't seem to find a MTF that makes the trans feel butter smooth when temps dip below 0...



There isn't one. I've used a ton of different 75w90s over the years and shifting is always a bit clunky when it's very cold.

The best I've ever encountered was Motul Gear 300, and that may be due to its very high viscosity index of 222. My old Audi's OEM fluid, Castrol TAF-X, was pretty close with a VI of 210 (it's not sold in the US except at Audi dealers for about $30/L).

 

[VNTS]

what fluid was factory fill?

I run the amsoil MTF in my Getrags in my PT's which came with ATF+4, shift fine in the cold, get some days in the -15F.

 

[Rand]

The Chevy M32 takes a very thin MTF. in fact redline has no recommendation for it(from their products)

I think in gear oil it would be a 70wt

usually for apps like these redline recommends their D4 ATF which is gl-4 rated but for some reason on cruze's they dont.

I'm currently using the very high VI motul 300 in my subaru.. but my subaru spec's 75w90 GL-5

Its ok shifting while stopped but trying to go 2nd to first while even rolling at
also can get a 1-2grind if you force it (at -10f)

i usually just start off in first uphill
at 10-15mph for 15seconds then its ok.

 

[Quest]

you can try to lessen the impact of cold(hard) shifting @ -26C, but you can never make it behave like summer time (cold).

gear oil gets thickened significantly in such low temp, no matter what you are running.

Try some boutique brand gear oils and see if that helps?

Q.

 

[Ramblejam]

Originally Posted By: Blue_Angel
Are there any manual transmission fluids (synchromesh?) that are known to work better at low temperatures? Do others have different experiences with this fluid at these temps?


https://bobistheoilguy.com/forums/threads/apparently-my-cruze-takes-dex-vi-and-its-a-mt.161401/

"Greetings from the Chevrolet Customer Assistance Center! This is a follow-up regarding your inquiry on GM part number 19259104...I was able to verify that the only thing you need to check on non-GM manual transmission fluids is that is should meet the GM Dexron VI specifications."

Amsoil Manual Synchromesh Transmission Fluid 5W-30 http://www.amsoil.com/lit/databulletins/g2080.pdf
Amsoil Signature Series Fuel-Efficient Synthetic Automatic Transmission Fluid - http://www.amsoil.com/lit/databulletins/g3110.pdf

Notably:

Synchromesh - Brookfield Viscosity @ -40°C (ASTM D 2983) 39,050
ATF - Brookfield Viscosity @ -40°C (ASTM D 2983) 9,015

 

[montero1]

Redline MTL shifts like I have been driving all day even in -4°.

(In my Mini).

 

[Drew99GT]

maybe try a bottle of Lubegard Gear fluid supplement? I don't know if the chemistry is compatible with synchromesh type fluids, but I use it with 75w-90 GL-5 gear oil in my Corolla transaxle and it's helped cold weather shifting noticeably. The Lubegard is quite thin at around 7 cst @100C

 

[IndyIan]

The motorcraft XT-M5-QS in the Focus did OK this morning in -32C. I did let it idle in N for a few minutes though so maybe it builds some heat in that time? Letting out the clutch after starting does drop the rpms by 150 or so, so the fluid is absorbing some energy. My up shifts were slow but fine though.
I have tried the GM synchro mesh fluid in the Tracker many years ago and I think it was fine in cold weather, but the Tracker's trans doesn't seem to "block" a shift in the cold with anything I've put in there, and I think was best with Can tire semi syn 75W90 GL-4 gear oil, but they don't sell it anymore. I suppose its some shell product though?
Maybe see if your trans can use this:
http://www.pennzoil.ca/wp-content/uploads/2012/04/Synchromesh Manual Trans Fluid.pdf

 

[Blue_Angel]

Originally Posted By: ARCOgraphite
Ive found new fluid to be balky for a few weeks right after its been changed out. Is the syncromesh a 75w or lighter? Pennzoil sync is grade equivalent to a light 5w20 oil, IIRC. What is the chevy MT fluid spec?


Amsoil Synchromesh is advertised as a 5W-30 weight, so maybe equivalent to a ~75W-85? Here's the product page:

http://www.amsoil.com/shop/by-product/tr...on-fluid-5w-30/

They advertise Brookfield Viscosity @ -40C = 39,050

They claim right in their product description that it "Improves cold weather shifting" and protection to -40, lists a 190 VI. You are not the first person I've heard saying transmission fluid gets better as the first week or two goes by... maybe I need to give it a few more days before judging it.

I have no clue what the GM fluid was. The manual calls for GM PN 19259104 but I can't find any information on it. Apparently the assy plant changed the manual transmission fluid they were using at some point, so I have no idea what I drained out.

 

[Blue_Angel]

Originally Posted By: Ramblejam
Originally Posted By: Blue_Angel
Are there any manual transmission fluids (synchromesh?) that are known to work better at low temperatures? Do others have different experiences with this fluid at these temps?


https://bobistheoilguy.com/forums/threads/apparently-my-cruze-takes-dex-vi-and-its-a-mt.161401/

"Greetings from the Chevrolet Customer Assistance Center! This is a follow-up regarding your inquiry on GM part number 19259104...I was able to verify that the only thing you need to check on non-GM manual transmission fluids is that is should meet the GM Dexron VI specifications."

Amsoil Manual Synchromesh Transmission Fluid 5W-30 http://www.amsoil.com/lit/databulletins/g2080.pdf
Amsoil Signature Series Fuel-Efficient Synthetic Automatic Transmission Fluid - http://www.amsoil.com/lit/databulletins/g3110.pdf

Notably:

Synchromesh - Brookfield Viscosity @ -40°C (ASTM D 2983) 39,050
ATF - Brookfield Viscosity @ -40°C (ASTM D 2983) 9,015


Intersting... and viscosity @ 100C is ATF 7.5 and Synchromesh 9.7. A much greater viscosity difference at low temps than at high temps. May be worth looking into farther. Thanks!

 

[Blue_Angel]

Originally Posted By: IndyIan
The motorcraft XT-M5-QS in the Focus did OK this morning in -32C.


A quick Google search suggests the Miata guys love this stuff... wonder if it's compatible?

 

[Blue_Angel]

Originally Posted By: montero1
Redline MTL shifts like I have been driving all day even in -4°.

(In my Mini).


I've read good things about RL MTL, but there was a case where a Cruze owner tried it and had issues. I don't remember specifics but they were not happy with its performance.

 

[440Magnum]

Originally Posted By: montero1
Redline MTL shifts like I have been driving all day even in -4°.

(In my Mini).


I have no experience with those kinds of temps, but I was going to recommend Redline as well.If anything is going to feel half-way normal in that kind of temp, I'd bet on Redline's MTx fluids (whichever one meets the Cruze viscosity requirements).

But frankly- I wouldn't expect anything to feel quite normal until its stirred up a little bit.

 

[badtlc]

My redline MTL has been fine down to -5F but it is firm the first shift or 2 then fine.

You probably want something real thin like Pentosin MTF2 or maybe Fuchs 75W FE.

Good luck.

 

[Sunnyinhollister]

The GM fluid is advertised as a fully synthetic fluid made by Castrol I think. Also is referred to as BOT 303??? There's not a whole lot of info out there on it. From the MSDS it has a pour point of -66C (lower than Amsoil) and a flash point of 232C (Higher than Amsoil). The Kinematic Viscosity @ 100°C is 6.2 and the Kinematic Viscosity @ 40°C is 31. This probably explains why Amsoil and Redline have no direct recommendations for the product. The bottle also says made in Germany for what it is worth.

 

[Blue_Angel]

Originally Posted By: Sunnyinhollister
The GM fluid is advertised as a fully synthetic fluid made by Castrol I think. Also is referred to as BOT 303??? There's not a whole lot of info out there on it. From the MSDS it has a pour point of -66C (lower than Amsoil) and a flash point of 232C (Higher than Amsoil). The Kinematic Viscosity @ 100°C is 6.2 and the Kinematic Viscosity @ 40°C is 31. This probably explains why Amsoil and Redline have no direct recommendations for the product. The bottle also says made in Germany for what it is worth.


Very nice info - thanks! I wonder if the BOT 303 Castrol syn is what was in there to begin with? Some Cruze owners claim the fluid coming out of their MT was like "black water", very thin and burnt looking. Mine, with a very easy 20k miles, was a nice relatively thick honey brown fluid.