Changed to Honda MTF - 3rd gear grinding

[wisdom62]

I just replaced my transmission fluid while I was replacing a axle seal. I used Honda MTF and filled it until it came out the fill hole.

This is the first transmission fluid change for this car while in my possession so I'm curious to what fluid was used by the previous owner. I didn't even think about checking the fluid when draining.

If they only used let's say a 10w-30 motor oil for the life of the transmission, would it be better to stay with motor oil or should switching to MTF be better? I didn't have the 3rd gear synchro grinding before I changed the fluid. I was thinking of trying another brand or type of MTF.

What do you guys recommend?

[oyajicool]

I would keep Honda MTF for now. See how it goes,,,.
It may get better.

If it doesn't, then use 10W30. See how it goes,,,,.

If you match the RPM there's less chance of gear grinding. The trick is finding that sweet spot of that RPM.

[mtnbikaah]

i'd drive it for a bit and then change it again with Honda MTF.

my old sedan had gear oil in it (I think so anyways). Drained and refilled with Honda MTF, ran it for a few weeks, drained and refilled again.

- 2 cents.

[TypeG]

that's kinda strange. it has been my experience that MTF takes away grinds on people's cars.

last car i put it in had the wrong kind of oil in the trans and it grinded 2nd every time. changed to honda mtf and it never did it again. later.

[tommi]

wouldn't hurt to put a magnetic drain plug in the mix. or use syncromesh

[wed3k]

I always did half synchromesh and half mtf

['93CB7Ex]

gm synchromesh is the shit.

[wisdom62]

Thanks for all the recommendations. I was always curious about synchromesh and my give that a try.

I will see how it goes with the Honda MTF for awhile and then probably drain and refill with MTF again and see. I do want to get a magnetic drain plug, its on the list of to do's.

If i do wait for the rpm to come down a before fully going into 3rd it is better but I know its something with the fluid. I'll post results in a few days. It helps that changing the M/T fluid is crazy easy.

Thanks again.

[accordztech]

On my z transmission it was supposed to always run ATF since it was a t5 manual. But the guy before always ran gear oil. When I put ATF it was so loud and ran funny. I ended up putting in gear oil and all the issues went away.

Stick to what he had before, or try out synchromesh.

[Losiracer2]

don't forget to get the friction modified version of GM syncromesh if that's what you want to run. Just warning you though, it stains the inside of the case a dark grey color vs. the Honda MTF.

After my rebuild my rebuild guy said stick with MTF only. I was there when he opened up my case and sure enough, the case was a dark grey inside compared to other trannies he had in his garage with the normal aluminum color.

[93redcb7]

iv heard from tuner shops that the gm syncromesh destroys our transmission slowly.

[Losiracer2]

iv heard from tuner shops that the gm syncromesh destroys our transmission slowly.

depends on what viscosity the fluid is too. I used Redline MTL for about 3 months, it was 75w90 in my M2A4 Craigslist tranny I found and in that amount of time, every gear was whining, almost sounding like a rally car w/ its straight cut gears.

Make sure that if you have to use syncromesh, that its not higher than a 10w30 viscosity

[foamypirate]

don't forget to get the friction modified version of GM syncromesh if that's what you want to run. Just warning you though, it stains the inside of the case a dark grey color vs. the Honda MTF.

After my rebuild my rebuild guy said stick with MTF only. I was there when he opened up my case and sure enough, the case was a dark grey inside compared to other trannies he had in his garage with the normal aluminum color.

I decided to try the Friction Modified Synchromesh in my 07 V6-6 for the 3rd gear issue. In my opinion, the Honda MTF I tried the first time around was much better. The Synchromesh was awesome for about 3 days, then started getting really notchy. The Honda MTF wasn't as nice right off the bat, but it stayed consistent, and was better overall then the Synchromesh.

[reklipz]

I'd like to hear more about the GM friction modified synchromesh slowly deteriorating the transmission components. Sounds fishy honestly, but the fact that it turns the cast housing dark gray makes me wonder.

I want to add: there is already a magnet internal to the transmission, so there is no real need to add a magnetic drain plug unless you're super paranoid.

[Losiracer2]

I decided to try the Friction Modified Synchromesh in my 07 V6-6 for the 3rd gear issue. In my opinion, the Honda MTF I tried the first time around was much better. The Synchromesh was awesome for about 3 days, then started getting really notchy. The Honda MTF wasn't as nice right off the bat, but it stayed consistent, and was better overall then the Synchromesh.

yeah I had the friction modified in my M2B4 when experiencing the dreaded 5th gear grind and it didn't seem to help one bit, and like you, the initial feel of it felt great, but I think after a month or so it started to wear off and didn't feel as crisp as it did.

The Honda MTF has a much better long term wear characteristic. My swap guy said to drain/fill it every other oil change, so for me it'd be 10k miles, but I would think that's too frequent, maybe every 3rd oil change so 15k would be more appropriate.

I'd like to hear more about the GM friction modified synchromesh slowly deteriorating the transmission components. Sounds fishy honestly, but the fact that it turns the cast housing dark gray makes me wonder.

I want to add: there is already a magnet internal to the transmission, so there is no real need to add a magnetic drain plug unless you're super paranoid.

The fluid seems to run very dirty. Idk why maybe it suspends more shavings from the syncros more so than the MTF? Either way, when I opened up my M2B4's case after having it in there for about 4k miles, it turned into a greyish muck. That could've been aggravated by my grinding/popping out 5th gear though.

I'll see once I drain/fill the current MTF siting in there after the rebuild (new 5th gear syncro, new mainshaft & countershaft bearings) how the color of the fluid looks.