I decided to swap tranny fluid from honda mtf on my 2004. I prob put no more than 1k miles on the honda mtf. Results:

While the honda mtf was good, still had ocassional notch. Amsoil...instant results. Gears are shifting smoother 90%+ of the time.

For those with "grind" or "notchy" shifting its likely due to the synchros not having the right fluid to do their job quick enough. Hence the 1-pause-2 shift technique. Having swapped to amsoil i feel this oil is better formulated for our tranny.

Just do it.

 

Changed mine to amsoil about a month ago! Initially it felt absolutely amazing, but after almost 1000 miles now I don't really notice any difference than before

 

There isn't one fluid that is best for all transmissions, it seems each transmission prefers a certain viscosity as it ages and each fluid has a slightly different viscosity and friction modifier formulation. There is a starting viscosity and then it begins to drop as you put miles on the fluid due to shearing caused by the meshing action of the gear teeth. You need to find the right fluid that works best for your tranny and learn when to change it at the right mileage as it shears down. My tranny still shifts like new after 60k miles on Honda MTF2 so I'm hesitant to try anything else, but I probably would if it started shifting poorly. I run relatively short fluid change intervals though - once per year and I don't drive it much.

I found that you can help the 1st-2nd gear crunch by adjusting the clutch rod (if you have too much clearance), and swapping out the clutch fluid on a regular basis (twice a year or so). I used to have that same crunch on my tranny when I got the car but it is completely gone now. If your clutch fluid is darkened swap it out and keep it clean with frequent fluid swaps - it only takes a tiny amount.

 

never used it in my s2k...but in my fg2 i had the same results. Works great for the first 1-2k miles then goes back to feeling like any other mtf.

 

pretty much the same for synchromesh...i changed from honda MTF to the synchromesh and it was buttery smooth for about 1500 miles and then the notchiness came back...but my tranny never felt "bad", it just has a slight notch from time to time, but i attribute that to how precise the transmissions on these cars are

 

Precisely! What works for one person may not work for another. I find it comical to see posts like, "Just do it". Unless you're talking to a room full of clones, this is not universally good advice.

 

Glad to see Viper back;for my part,I'm very happy with Redline MT-90.

 

Guys.. (and gals).. the gearbox is not a living object.
It is a mass produced mechanical device.
It does not have a mind of its own.
It is not a female (no offence) with moods.


IMO one can catagorize shifting issues into 4 options:
#1 - the driver - this means YOU - is doing it wrong.
For example: you shift too fast especially at lower revs, your hand-foot coordination is wrong, you do not allow a warm-up.
#2 - mechanical adjustments.
For example: clutch hydraulics, clutch pedal to master adjustment, shifter itself, transmission input shaft (IMPORTANT ONE)
#3 - maintenance, linked to #2
#4 - actual wear.
For example: due to skip shifting, running oil for way too long or al low level.

IMO: when one solves the mechanical adjustments most-if-not-all of the shifting issues will be gone.
The oil will play a minor role in it from that point.
This means one has to properly flush & bleed the clutch master & slave, polish the slave push rod and use good lubrication at both ball-ends, lube any linkage at the clutch pedal.
Then the free play at the master can be adjusted to almost gone but remember to feel hydraulical "play" as you do not want to ride the throwout.
Also, the plasic shifter bearings need to be in good condition and well lubed - with a non solid compound grease.
One thing will be harder to do and that is the trans input shaft splines.
Once those splines are rusted there will be some shifting issues, no matter what you do.
The clutch disk needs to be able to break free from the FW by its own to get a smooth shift.
If the disk can not slide away it will kinda stick to the FW and breaks free once you select another gear: the crunchy shift has happened.

Before I installed my clutch myself - during an engine swap - I used several oils.
Honda MTF, GMSFM and a brand I found on BITOG, it was highly recommended.
There were little differences.

The largest improvent came after I made pretty damn sure those splines were clean and lubed during the clutch install.
Shifting has been perfect up until today.
I am using Amsoil though, but I'm sure MTF or others will work as well.

 

I guess I should've been more clear.

Like many, I experienced the more than occasional notchy shifting in my S when I first got it. Being a low mileage stock S, I figured there was some maintenance and mechanical adjustments needed to be done.

I had already done the Honda MTF Flush last year before storage and then followed up with the clutch rod free play adjustment, the regreasing of the shifter housing, heavier shift knob, cleaned out the brake fluid in the clutch lines, and also adapted my shifts with a slight pause and at higher RPMs. All these helped tremendously. However, even with all that I found that the notchiness was still there from time to time.

Flash forward to today having heard good things about amsoil MTF, the oil change itself made more noticeable difference than all the other contributing factors. So while I don't think its the "end all" solution for all trannys, I believe its a step in the right direction. For those who are experiencing notchy shifting and have done all the things I even tried with less than expected success, I encourage them to try changing out their MTF fluid to amsoil. Perhaps with the carbon synchros in the 04-05, that the stuff is jsut formulated better to work with those MY.

 

put about 1000 miles on that fluid and get back to us...id like to know how it holds up to use and thermal breakdown