KmanRuffian

Ok so I changed my tranny fluid today and threw in a quart of synchromesh with the rest GL5 75W90 dino oil. I drove the car around for about an hour and I have to say it doesn't feel much better/different from when it has clean transmission fluid in it. It might be a tad smoother than usualy but if it is, it isn't blatantly obvious. So I was thinking to myself how can all these people have such amazing experiences with the stuff, saying it changed their tranny/car completely and what not. I came up with this theory, it's all about your shifting style/technique. Those who rely heavily on their synchros will probably notice the effects of the synchromesh oil alot more than those who don't shift into gear with alot of force or don't shift really quickly. I rev match on every downshift and when I shift it's a two-stage process, into neutral with pressure into the next gear, then as the synchro does its job it slides into gear. There is always a definite pause in the neutral postion though. I always use a light touch when shifting. I basically shift as this page instructs http://www.spdusa.com/shifting.htm "wait for the machinery to do its job" I don't shift slowly, just as quickly as the machinery allows me to but I don't bang it into gear. Because of my shifting style, I never get any grinds or anything, I never rush into first gear with lots of pressure, I'm sure I could make it grind if I did, I just apply steady pressure until it slides in. So basically I don't rely heavily on my synchros so I didn't notice much difference, I might as well have gone with all regular GL5 fluid I think. So anyway those are my thoughts on this stuff. If you get grinds then its likely you tend to rely on your synchros more and shift with more force/speed and this stuff will help. If you don't have any tranny issues then this stuff isn't gonna be a miracle fluid that makes your tranny feel like a honda or something.... Hope this helps.

KmanRuffian

Synchromesh is not synthetic. And as for the difference between synchromesh and MT-90, they are different fluids. MT-90 is a synthetic, GL4 rated fluid of viscosity 75W90. Synchromesh is GLS rated which we speculate to be hovering near GL4 specs simply because it says it is for "some" GL4 applications. The synchromesh has some friction modifiers in it that help supply the synchros with more friction.

PHATsuby

thanks yea i looked it up, actually MT-90 is Gl-4 as far as i know, which is why you cant run it straight in our trannies.

i will run the redline i think

thanks

Ben

KmanRuffian

My mistake, yeah I meant GL4...

erod45

My only concern with using the syncromesh is that the front differentials share the same housing ( and oil) with the transmission, therefore, the syncromesh will had friction ( which the diffs do not like) thereby increasing it's wear. I think that is why Subaru suggested using GL-5 gear oil for it's transmission. I dunno - what do you guys think?

Ellery

ride5000

ellery: in my mind, the choice was simple really...

how many folks have worn out their front differentials? how many broken front diffs do you hear about? how many warrantee claims?

-vs-

how many folks have worn out their gearbox synchronizers? how many warrantee claims?


see my point?

ken

Got Groceries?

Made the jump this weekend with a mix of 1 quart Pennzoil Synchromesh and the balance being Castrol Hypoy-C 75-90 gear oil. My only transmission complaints before the switch were grinding going into first from a stop (sometimes - which I worked around by selecting second gear, then first), and "notchy" feeling gears overall ESPECIALLY from first to second gear.

Now, I can't say that it's night and day different, but there is a noticable difference in overall smoothness while shifting, especially downshifts. I'm currently re-training myself NOT to select second gear then first when starting out, and have had zero occurrences of grinding in that situation (in two days of driving...jury's still out). In fact, I'm thinking I may drain out a quart of fluid and replace it with another quart of the Synchromesh to get more of a 50/50 mix.

Thanks for the sleuth-work folks, good info!

pdqwrx

iTrader: (3)

I too just added the quart of Syncromesh to a really new oil change with RedLine and I must say that I too felt a big change. For the first week or so with the RedLine things seemed better (Over the stock fluid) but soon the grinding came back and the "New" tranny feel went away. I now have a even better feeling in the tranny and it seems to be lasting. In fact, I just downshifted from 3rd to 1st at about 17 mph (I squinted and ground my teeth as I did it) and I don't remember ever being able to do that before, ever. If my diff wears out then maybe I'll convert it to rear wheel drive, until then I am watching the money I have saved up for the RA gear set collect interest.
Thanks to I-Club for bringing this great find to the forum.

Later
PDQWRX

erod45

Well, I finally put in the GM/Penzoil synchromesh and I must say, that stuff really works. I only put in 0.5 quarts and filled the rest with Castol Hypoy C 75W-90. The transmission is much smoother and alot quieter. I also noticed that it isn't as notchy as it was before, even with the kartboy short shifter that I have in it. i placed it in this past Saturday and had a chance to wring out the transmission since then with alot of city and highway driving. Not a single grind noted.

caballo77

iTrader: (1)

hi:
well, after using straight amsoil synthetic in my 04's tranny I decided to try a cocktail of amsoil 75w90 and pennzoil syncromesh at about 2:1 ratio.

I was reluctant to do this thinking the amsoil would have been "good enough" (and not wanting to waste a fresh refill).

Well...there is a difference. Shifts are noticeably smoother. This is a great and easy fix for the notchy, grindy trans. I didn't know the shifts could be this smooth.

Thanks!

subawho?

iTrader: (2)

15k miles now on just 1 quart mesh mix and still smooth as ever. I'm glad its working out for everyone for the most part.

funkendrenchman

Just changed transmission oil and put in 1 qt synchromesh, 2.7 qts Penzoil 80W 90 GL5. The result... works just like everyone said. Instead of having to slow to less than 5 mph I can shift into first at 25 mph with no grinding and just a little notchiness. Shifting into reverse is way smoother also. I haven't had a chance to check out 5th gear but I'm sure it will work there too. Still not perfectly smooth, but much much better!

I wish every 2002 WRX owner could read this thread.