i77ac_10

So after reading about different transmission fluids on the forums, I decided to give GM Synchromesh FM a try since there seems to be a lot of hype and generally positive reviews about it.

Its been in the car for only about a month now and I'm already beginning to wonder if I should swap it out for the factory honda stuff. Bare in mind that my impressions are mostly from street driving of my short daily commute (< 12 miles).

Right off the bat I did notice a difference. Its difficult to describe, but the feel of the shifting changed in a subtle but noticeable way. The shifter seems to slide into the gears better. However, at the same time it felt less precise.

Before I go any further, let me describe my shifting habits. When I shift I usually try to apply a minimal amount of pressure to the shifter. I do this under the impression that its easier on my synchros (wild guess, i'm by no means no expert here...). By applying this minimal pressure, the shifter will slide into gear as soon as the engine/tranny speeds synch up.

With that in mind, I'll try describing the GM SM FM fluid by breaking down a gear change into 3 parts:

1) Applying minimal pressure to the shifter while it is in neutral.
2) The initial resistance from neutral to a selected gear once engine/tranny speeds start to synch.
3) The resistance after 2), putting the shifter fully into the gear.

1) feels essentially the same with the GM fluid.

Parts 2) and 3) is where I feel the most difference. 2) feels like it goes in easier than stock but once it begins to go in (we're part 3 now) it doesn't have the same popping feel as w/the oem fluid. Part 3 feels like theres more resistance and doesn't give as much of a positive feel of putting the gear in all the way. I would describe it as feeling sloppy.

On the other hand, with the factory fluid, I felt that there was more pressure initially, then it popped into gear nicely once it started to go in. Does anyone else notice this difference?

Perhaps because the factory fluid is thinner (synchonizing slower, although more accurately), thus making the moment 2 happens more precise, causing 3 to slide in nicely?

oakfloor

how many miles on your car? they need time to break in for smooth shifting when new. maybe it needs to warm up. mine shifts way better when its warmed up. if there is no improvment with the GM stuff try redline MTL, for cold climates, or MT-90 for summer. it works great in my car. and its better oil than the factory stuff. IMO

CarBoN

are you saying that your not pushing the clutch in when your doing this?

TwistedS2k

my experience with Gm synchromesh is a little difference. The shifting isn't as smooth and buttery like some people's here. I might try the redline fluid on my next replacement or go back to mobil 1, who knows. But I will not use GM synchromesh again.

RM 4 2

I used to have Mobil 1 in my03 and like it a lot, don't know how it runs in winter, though, I changed the oil in spring and sold the car in that mid summer.

Now it's time to do my04 first oil change, I kindda don't know what to put in for the tranny oil. I've heard that Mobil 1 sync gear lube doesn't do good in the new AP2 CF syncros..

Thanks for sharing and sorry couldn't be more helpful here.

bent240LV

i used redline MT90 in another car before and i thought it was good. i recently put in mobil1 and think it is good as well. the good thing about mt90 is that it is one of the few GL4 oils out there also try neo oil i heard is pretty good but a little higher priced than red line.

i77ac_10

No, I'm not saying that I dont use the clutch. I was just zeroing in on the shifting feel.

oakfloor,
I have approx 27k on the odo.

I'm glad you guys mentioned mobil 1. I was just wondering if that would be a good synthetic alternative to the using the oem honda stuff. Anyone have experience w/the mobil 1 in cooler climates?

i77ac_10

is this what you guys have tried?

http://www.mobil1.com/USA-English/MotorOil...e_75W-90LS.aspx

I noticed that there is an LS version of that oil for LSDs. I believe I put he above product in my diff. Was I supposed to use the LS version?

S2KenC

Mobil 1 75w90 gear lube is meant for the differential and not the transmission.

And yes, this gear lube is okay for the S2000 DIFFERENTIAL (All Years).

xviper

HOLD ON! This thread started out talking about TRANSMISSION fluid. Then, all of a sudden, someone brings up REAR DIFFERENTIAL fluid. DO NOT get the two mixed up with one another. You CANNOT put something like Mobil 1 gear oil that is meant for our diffs into our trannies.
Let's NOT get off topic and confuse the heck out of people.