So I had a 5-speed swap done to my car before I bought it. I've owned the car for a year now and never had any issues with the drive-train. I decided to change all the fluids out with Amsoil // Diaqueen.

Transmission for the most part, feels even smoother then it ever has. However, now I am noticing a big issue with getting into 5th gear. Especially after merging/passing a car in 4th. I ALWAYS grind into 5th gear now. This was never an issue before.

Unless the speed is relatively low, it almost always grinds now. It's such a irritating feeling when grinding into gear, and I am sure it's destroying it.

Any reason for this to only be happening in 5th? Before the fluid swap it was absolutely perfect.

Fluid is:


Any ideas? Or maybe I should just go with OEM fluid?

 

From what I understand, they all do, eventually. 5th had a single synchro, so will grind if driven hard.

 

That's so weird that this suddenly happened after a fluid change. I started convincing myself that I had not put enough fluid, but I did. Now convincing myself that I need better fluid in there. Was perfect before.

 

I swapped my transmission at 114K because of a vibration in 5th gear (there's a TSB on this - factory error) but never had a grind into 5th. I always used diaqueen.

 

Change fluid to Redline MT90,
It's likely the smoothest shifting Evo 5 speed gear oil and it generously improved my owns car propensity for grinding 5th synchro.

 

More then likely a worn synchro. It may have damaged gears but cant tell untill you disassemble.

 

What fluid did you have before in the trans? have u tried a GL5 product like motul gear 300

 

I sadly do not know. Don't really have contact with the previous owner.

The only product I've tried so far is with the Amsoil mentioned above. It's my first flush and fill.

 

Just placed my order of Redline MT-90. I use this on my GSX, so I know its good stuff. Hopefully helps with the 5th gear grinding. Arrives Sunday so will keep posted.

 

Do I toss on my trans, use a diff fluid, and hope the grind goes away? Or just suffer through current trans and replace worn parts on the one waiting to go in?
probably makes sense to be patient and rebuild. Car will be parked from Aug-May, anyway.
No sense in installing it twice...

 

I had a fifth gear grind once. Took my Evo to English to check it out along with swapping to VIII third and fourth gears and to upgrade the clutch while it was all apart. Walked away needing a complete trans rebuild. At least now I have a completely brand new, built trans.

Moral of the story - this could be a lot worse than you're expecting. Make sure you got a nice chunk of cash just in case.

 

Bummer, I really didn't think this issue was all that bad. Especially since it just started right after the fluid change.

Was planning on taking the car to the shootout this year ( not racing of course ). After Oct ( when snow becomes possible ), was going to have the clutched changed since whats on there now is too heavy for my liking.

 

It's probably not a huge deal. I just fixed a 5th gear grind in a client car. Replaced the gear, synchro, sleeve, and springs. Worked great. Rest of trans looked fine.

 

+1

Im paying $550 for all parts and seals for mine and that's INCLUDING a JDM 5th gear set. Not bad.

Sean: come do mine.

 

What is the advantage to the JDM 5th gear? Just wondering for whenever I have my trans rebuilt.