2nd gear synchro FIX- MT owners read this thread

[coyote]

Originally Posted by getbent

So is everying going to 75W80 simply to solve the performance in the cold? Nobody has any reservations that the operating temperature thickness of 75W80 (7.7 cSt) is significantly less than 75W90 (~15 cSt)?

Excellent question. This thread seems to be about improving cold shift quality, yet the comparison of viscosity has been for temps of 100C.

Originally Posted by gmookher

Manual Transmission Oil Viscosities

ATF type MTFs: 6.0 – 7.5 typical
Honda semi synthMTF II 7.5
Royal Purple Synchromax 7.7
Pentosin MTF2 7.5

GM/Chrysler Synchromesh type: 8.5-10.0 typical
Torco MTF 8.35
Pennzoil Syncromesh: 9.08
Amsoil MTF (5W-30) 9.6
Red Line MTL 10.6
Honda MTF 1 10-11?

75-85 Gear Oils: 12.0-12.5 typical
Specialty Formulations MTL-P 12.0-12.5
Castrol Syntorq 75W-85 12.0???
Nissan 75W-85 12.0???
MT-85

90 weight Gear oils: 15-16.5 typical
Royal Purple Max Gear 14.5 (Published: 21)
Amsoil MTG 14.7
Pennzoil GL4 75W-90 15.3
Red Line MT-90 15.6

Your cold shift quality comes from the Kinematic Viscosity at 40C. The reason why Pentosin MTF2 shifts so well when cold is that it is 38cSt at 40C. That's also why it runs like water. I haven't seen the label (we don't get it here), but it's is probably 70W80.

Not sure how I'll go, but I'll try to put together a table of the gear oils being discussed, at both 100C and 40C. Choosing which one is right for you is a balance between low temperature shift quality and high temperature protection.

Couldn't do it, so made a pdf. Hopefully someone bothers to open it and I haven't wasted my time. If people want to find the data on their favourite fluid, I promise to think about maybe possibly updating the pdf. Perhaps. Someone a little more interweb savvy could probably come up with a better idea though.

It's currently 7:50PM here and still 26C outside. Tomorrow's forecast is for well over 40C. I'm currently putting together a turbo setup that I'll test relentlessly on the track. All that is relevant.

[Panman]

So, going on the excellent chart you've provided the (potential) downside of Pentosin is it's lower KV at higher temps and therefore lower protection.

Given Coyote and I are both at Lat 27, I'm happy with my current setup.

Motul Gear 300
Perrin Rear shifter bushing
Cusco Stiffener
BPS Short shift.

When the car is (properly) up to temp it's perfect in weight/throw and feel.

Clearest explanation yet of the tradeoffs in that one PDF (And yes at 11 pages although I've been in and out of this thread I haven't read every post).

[coyote]

Thanks for that Panman.

I'm not saying that Pentosin is bad. I think it's pretty well established that the factory fill oil does not provide satisfactory shifting and no-one likes pulling a gearbox apart to replace synchros. Everything is a trade off and what's right for you depends on your specific application.

Note that the lubricants on the chart below the space are all within factory recommended spec. The ones above are not.

[bluesubie]

Originally Posted by coyote

Excellent question. This thread seems to be about improving cold shift quality, yet the comparison of viscosity has been for temps of 100C.



Your cold shift quality comes from the Kinematic Viscosity at 40C. The reason why Pentosin MTF2 shifts so well when cold is that it is 38cSt at 40C. That's also why it runs like water. I haven't seen the label (we don't get it here), but it's is probably 70W80.

Not sure how I'll go, but I'll try to put together a table of the gear oils being discussed, at both 100C and 40C. Choosing which one is right for you is a balance between low temperature shift quality and high temperature protection.

Couldn't do it, so made a pdf. Hopefully someone bothers to open it and I haven't wasted my time. If people want to find the data on their favourite fluid, I promise to think about maybe possibly updating the pdf. Perhaps. Someone a little more interweb savvy could probably come up with a better idea though.

It's currently 7:50PM here and still 26C outside. Tomorrow's forecast is for well over 40C. I'm currently putting together a turbo setup that I'll test relentlessly on the track. All that is relevant.

Since 40C really isn't that cold, use this viscosity graph to get a better idea of viscosity at 0C: http://www.widman.biz/English/Calculators/Graph.html
Just plug in the 40C and 100C values and it will give you the 0C values.

-Dennis

[coyote]

Sif anyone would live where it got to 0C.

[fenton]

Anyone know where to get this stuff in Canada?

I tried to order off of Amazon but they wouldnt ship to me.

Called local BMW but they said they have MTF3 not 2?

[gmookher]

I get teens at nite where I live at elevation in the desert in the winter.. then I get 115F heat too in summer, so this is my all year fluid, and it really need not be changed often at all, atleast not from degradation or anything.

This fill will see easy 25000-30000 miles before I flush it, and thats with high hp track use planned for the supercharged car.
If you daily drive a NA with mods up the waazzuuu, BMW -m cars dont excactly come underworked from the factory, they are also demanding as far as EP demand, shear and flow specs, and heat and cold are very much part of their game-considers it a LL fluid, by most euro standards, thats pretty high miles. Our stock BRZ, will likely see 60,000 before I flush its tranny again, and refill with Pentosin for another 60,000 miles.

I am sorry dunno where you can get the MTF2. I do not think the 3 is the same stuff, and dont suggest you 'try it'

[wtout86]

Originally Posted by fenton

Anyone know where to get this stuff in Canada?

I tried to order off of Amazon but they wouldnt ship to me.

Called local BMW but they said they have MTF3 not 2?

http://www.ft86club.com/forums/showthread.php?t=24716

[wtout86]

Actually a little update. I have almost 2000km on the pentosin and its doing great. I had problems with the stock fluid, tried Amsoil and Redline, mainly because I couldn't get my hands on the Pentosin. Both the Amsloil and redline had the same problems as stock. The Redline especially, anywhere near or below freezing I could hardly shift into second, I would often skip it for the first 20 min of driving, witch was a major pain in the ass as I was going to school downtown Toronto at the time. The Pentosin was better right off the bat, but not by much, still some resistance going into second but no awful "CRUNCH" that many have felt. As I got more miles on it it just got better and better, after 500km it was pretty good, past 1500km it was perfect.
This is a great fluid for this car from my experience. Can warm up the car for a minute or so at -5c or colder and it shifts beautifully, still have to take it easy for a little bit, let it warm up, but that's a given. No more "CRUNCH" no more resistance. Still have kind of a weird "notch" or "catchy" feeling going into third sometimes. Hoping the Perrin shift bushing will remedy that, I also have the Whiteline trans mount bushing and Positive Traction kit ready to throw on. Cant wait to feel the results.

[Panman]

Originally Posted by wtout86

Still have kind of a weird "notch" or "catchy" feeling going into third sometimes. Hoping the Perrin shift bushing will remedy that, I also have the Whiteline trans mount bushing and Positive Traction kit ready to throw on. Cant wait to feel the results.

I have both the Cusco Trans Mount and the Perrin Shift bushing in my car, and they make the shift more direct - if it's notchy or catchy now it'll be more not less noticeable unless the notchy feeling is due to box movement (which I can almost guarantee it isn't).

[Bonburner]

Spent an hour 40 reading this entire thread, pretty fun and I'm glad I have some oils of interests now ...

[nix]

Originally Posted by Panman

I have both the Cusco Trans Mount and the Perrin Shift bushing in my car, and they make the shift more direct - if it's notchy or catchy now it'll be more not less noticeable unless the notchy feeling is due to box movement (which I can almost guarantee it isn't).

Same here and it's still catching into 3rd sometimes as well.

[gmookher]

Originally Posted by Bonburner

Spent an hour 40 reading this entire thread, pretty fun and I'm glad I have some oils of interests now ...

funny part is its 40 pages of lets try this instead...and my tranny suck, should I try this?

[nix]

I haven't gotten around to oil testing yet but my ambient temp range is 60-120 seasonally but usually 70-85. The 3rd gear shift is really pissing me off it happens more once gb is properly hot.