So, I've heard many reports of 5th gear synchros going out. Bit of background, I have an 03 Evo which I acquired just over a year ago with 53K on the clock, has 58.5K now. About 2000 ago I changed the tranny fluid from ??? to BG Synchroshift II. I have noticed that 5th gear doesn't engage quite as easily as the others. With a warm tranny, 2nd through 4th fall in almost with no resistance. 5th takes a bit of a push and seems to take an extra split-second to engage. Also feels slightly notch sometimes. However, even when shifting at 5K RPM or so (I didn't feel like going higher on the street last night ) I can't get it to audibly grind - just a little notchy. Is this a bad thing? Or is the slight notchiness normal for 5th gear in Evos?

 

get used to it...its normal....mine started at 30,000......

 

my 5th grinds heard its a pretty common thing though

 

i have the grind at 35k

 

evo trannys are notchy from nature, syncros are beefy, however watch your syncros when then go they go, my 5th was gone it would not take 5th in anything higher than 4500 rpm, replaced it and no problems

also change that oil you are using is great for the syncros but horible for the gears, it doesnt protect them at all

 

^ Yeah... first thing I'd do is get that BG Synchroshift out of your tranny.

 

Redline MTL/Redline MT-90 worked great for mine...MT90 for gear protection and the MTL mixed in gives me very slick shifting...with an 05 stock tranny with 83,000 miles and I'm pushing between 450-500 hp.

 

^ This.

I've been running Redline forever now. I plan on switching to AMSOil to test it out since I've heard good things about it.

 

Hmmmmmm, I've got an 06 IX (25k), just changed the tranny fluid and put BG Synchro II in it. Now I notice a 5th gear whine-growl when letting off the gas at highway speeds. If I mash the clutch and let it freewheel, it is quiet, it only makes the noise when backdriving the engine and only in 5th.

In fact the whole tranny seems a little more noisy and more notchy.

 

I heard it was normal. Mine started at 22k

 

started at 30k for me

 

contact MILSPEC for some fluid... i use there 6speed fluid for my MR, i have 50k with a perfect tranny and LOTS of roadracing/spirited driving, and people always dog on 6speed tranny's

 

This is exactly what I do too. Could not be happier so far after I rebuilt my tranny last month (myself).

To anyone who said it's normal for a gear to grind you are terribly incorrect. My EVO tranny had 65k on when I did the rebuild (had a grinding 4th gear from previous owner) My 5th gear was perfect, as were the syncros and the syncro sleeve (what some call the slider). In fact there was no reason to even replace those parts. If you have grinding, you will have a damaged syncro sleeve, syncros, and very shorty after that speed gear. BTW 4th and 5th grind easily due to the fact that they only have a single syncro, and won't take much abuse or bad shifts. 1st and 2nd are tripple, 3rd is double.

To the OP, get that BG fluid out of your tranny. The only fluids you can use in the EVO tranny are:
Diaqueen transmission fluid
Redline MTL and MT-90
Amsoil MTG

Take your pic of those 3, any of the Autozone, and other off the shelf gear oils have a GL-4,GL-5 rating and that is NO NO with the GL-5 and syncros.

 

serious question, is royal purple performance manual transmission fluid and gear oil any good to run in an '03 5 speed evo viii?

 

^^^ I wouldn't read my post a few replies up.. those are the ONLY things you should use in the tranny.