Looking for all EVO 8, 9 people with 6 speed still.
Oct 28, 2015, 12:57 PM
#196
I didn't read all the posts in this thread, but it's really just 4th gear that is weak in the 6 speed simply due to it's smaller size to fit in the same packaging.
Also, what I'm not so sure if it's been mentioned, you are more likely to break it by being lazy and accelerating in 4th. You should always change down. Acceleration in 4th from low rpm is loading up that gear the most.
Also, what I'm not so sure if it's been mentioned, you are more likely to break it by being lazy and accelerating in 4th. You should always change down. Acceleration in 4th from low rpm is loading up that gear the most.
I remember reading somewhere, with pictures of both gears and I don't think they were actually different in width or atleast very little difference, as a millimeter or 2. I always believed that the 6's just don't like heat or abuse for long periods of time at circuit tracks. Mine has always done well with frequent fluid changes. And that is with 2 different trans. And the second having a grind in 4th. (
Oct 28, 2015, 01:27 PM
#197
If mine dies, I will rebuild with a trans cooler/pump.
Oct 28, 2015, 06:34 PM
#198
I also did not switch trans because of failure. I was under the impression that the spare I had with less miles was better than mine. But I wasnt, and Motul fixed it. Amazing I know, and out of all the daily driven and somewhat harsh beatings mine had never broken. I plan on trying this season and possibly installing a temp sensor, so I know what temp it was when it failed, and hopefully start a thread on why it failed
Oct 28, 2015, 06:39 PM
#199
Lots of speculation, but no proof. Between the difference in size and the .5qt less fluid, I guess it gets too hot. I, personally, don't know of anyone that had broken a 6spd. Now having said that, I better go change my fluid LOL
If mine dies, I will rebuild with a trans cooler/pump.
If mine dies, I will rebuild with a trans cooler/pump.
Every person along the way of my build had told me my trans will self destruct but it hasn't yet. Even my tuner and engine builder said it wouldn't last on the dyno with an FP red, but here I am. So out of all the stuff I have tried, with an exedy twin disk, the Motul 300 fluid bing changed every 3 oil change seems to do the trick. I change my oil every 1500 miles.
Oct 28, 2015, 10:53 PM
#200
I honestly don't think a trans cooler is required unless your circuit racing because of all the heat. And there is proof here on EvoM I just have to find it, I think shep has posted pictures of the gear sets side by side. And I belive they were not much different. But a few millimeters of material may make a huge difference.
Every person along the way of my build had told me my trans will self destruct but it hasn't yet. Even my tuner and engine builder said it wouldn't last on the dyno with an FP red, but here I am. So out of all the stuff I have tried, with an exedy twin disk, the Motul 300 fluid bing changed every 3 oil change seems to do the trick. I change my oil every 1500 miles.
Every person along the way of my build had told me my trans will self destruct but it hasn't yet. Even my tuner and engine builder said it wouldn't last on the dyno with an FP red, but here I am. So out of all the stuff I have tried, with an exedy twin disk, the Motul 300 fluid bing changed every 3 oil change seems to do the trick. I change my oil every 1500 miles.
So, who knows?. I only know I like the 5 less, so will run the 6 fo lyfe.
I do AutoX and Time Attack. I don't think either of those are too bad on the trans. I spend most of my time in 2nd and 3rd then 4th, of course, only on the longer straights.
My only concern is HPDE because I go as hard as my tires let me, for all 20mins LOL
Oct 29, 2015, 12:20 AM
#201
Well if your 6 is running great while doing that, then I wouldn't change much than your fluid frequently. Just don't use Pennzoil Syncromesh. My trans hated it. After a few hundred miles of that stuff and I drained it to switch to Amsoil. But like I said above Motul seems to work the best. Even after longer drives, well into heat soak.
Oct 29, 2015, 12:56 AM
#202
Well if your 6 is running great while doing that, then I wouldn't change much than your fluid frequently. Just don't use Pennzoil Syncromesh. My trans hated it. After a few hundred miles of that stuff and I drained it to switch to Amsoil. But like I said above Motul seems to work the best. Even after longer drives, well into heat soak.
Synchomesh didn't seem to work in any transmissions other than the WRX cocktail.
Oct 29, 2015, 01:30 AM
#203
All I hear is popular opinion that they suck. Where? When? Maybe is someone showed me proof that the 6 has a failure rate higher than the 5 under similar circumstances.
So, who knows?. I only know I like the 5 less, so will run the 6 fo lyfe.
I do AutoX and Time Attack. I don't think either of those are too bad on the trans. I spend most of my time in 2nd and 3rd then 4th, of course, only on the longer straights.
My only concern is HPDE because I go as hard as my tires let me, for all 20mins LOL
So, who knows?. I only know I like the 5 less, so will run the 6 fo lyfe.
I do AutoX and Time Attack. I don't think either of those are too bad on the trans. I spend most of my time in 2nd and 3rd then 4th, of course, only on the longer straights.
My only concern is HPDE because I go as hard as my tires let me, for all 20mins LOL
They do hold .5qt less oil, I personally know since I've changed my fluids many times. I tried to overfill to compensate but it died anyways. I broke my 6 spd with a mighty 300whp but with 25+ track days that I put myself on it (I know the previous owner tracked too). Razorlab went through his stock 6spd and a TRE rebuilt unit with just under 400hp with track days too, check his thread from 2008. Another track-only evo making 450ish whp local to me has put 3000ish miles on it since it was built in 2011, but all track miles. The 6spd broke on last year's season. The only 6spds I see stay together are the DD ones that maybe see 4 HPDEs a year.
The common wisdom on 6spds btw is to use OEM diaqueen only. It may not shift great, but thats what helped people keep their tranny in one piece for longer.
Last edited by deeman101; Oct 29, 2015 at 01:33 AM.
Oct 29, 2015, 08:43 AM
#204
^^^^^, This is a good summary from my experience as well.
I have been through a couple rounds of 6speeds. Without smoking gun proof I would say the first failure was just the 4th gear grind. That came about from tracking. HPDE. The extreme heat causes the oil to eventually foam and lose its effectiveness, this will cause (as MrFred notes) a syncro engagement degradation. You will likely miss shift fourth, as I did pulling onto a straight at Spring Mountain. This is a User Error issue. I drove in a style of endurance racing at this event because almost nobody showed up and it was open track time. No run sets, just open. I did not give the car any cool down and ultimately paid the price. I could still drive it, but 4th engagement was degraded. Eventually I had the trans rebuilt by Shep with the 3,4,5 custom gear sets. So again, heat here was the killer.
I am in the middle of another rebuild, due to a rattle internally, but I don't think its relevant to this discussion yet.
Another comment I had was that the profile of the gears is critical as well. So not only do custom gears get the slightest bit wider if possible they change the profile of engagement.
Managing heat (along with your driving style) is the key. So if you run track days avoid more than 10 laps. My own rule since all this started for me. Make sure you have an hour between sessions for cool down. Yes, slightly overfill the trans, as it helps cool a bit better.
Remember too that clutch drag can be a killer for the 'grind' some of you are commenting on. Make sure your clutch is adjusted and not dragging as it punishes the syncro in a way that wears and eventually makes it fail.
Heat is the enemy, power is the multiplier.
I have been through a couple rounds of 6speeds. Without smoking gun proof I would say the first failure was just the 4th gear grind. That came about from tracking. HPDE. The extreme heat causes the oil to eventually foam and lose its effectiveness, this will cause (as MrFred notes) a syncro engagement degradation. You will likely miss shift fourth, as I did pulling onto a straight at Spring Mountain. This is a User Error issue. I drove in a style of endurance racing at this event because almost nobody showed up and it was open track time. No run sets, just open. I did not give the car any cool down and ultimately paid the price. I could still drive it, but 4th engagement was degraded. Eventually I had the trans rebuilt by Shep with the 3,4,5 custom gear sets. So again, heat here was the killer.
I am in the middle of another rebuild, due to a rattle internally, but I don't think its relevant to this discussion yet.
Another comment I had was that the profile of the gears is critical as well. So not only do custom gears get the slightest bit wider if possible they change the profile of engagement.
Managing heat (along with your driving style) is the key. So if you run track days avoid more than 10 laps. My own rule since all this started for me. Make sure you have an hour between sessions for cool down. Yes, slightly overfill the trans, as it helps cool a bit better.
Remember too that clutch drag can be a killer for the 'grind' some of you are commenting on. Make sure your clutch is adjusted and not dragging as it punishes the syncro in a way that wears and eventually makes it fail.
Heat is the enemy, power is the multiplier.
Oct 29, 2015, 10:44 AM
#207
You adjust the pedal pedal under the dash. the rod end of the master cylinder has a jam nut on it.
I think overfilling has helped my trans as well. Since i don't have a lift, when i fill my trans, the front end is on jack stands. about 1-2 feet in the air. This way the fluid doesn't start coming out of the fill when it should, so i usually get 2.6-2.7 quarts in it, instead of the recommend 2.3 (
I think overfilling has helped my trans as well. Since i don't have a lift, when i fill my trans, the front end is on jack stands. about 1-2 feet in the air. This way the fluid doesn't start coming out of the fill when it should, so i usually get 2.6-2.7 quarts in it, instead of the recommend 2.3 (
Oct 29, 2015, 10:52 AM
#208
So it seems like heat is the culprit. Has anyone fabbed a reproducible trans cooler setup MR owners can copy? Correct me if I'm wrong, but a tranny cooler system is a better investment than the PPG gears, for longevity.
Last edited by Thrilla; Oct 29, 2015 at 10:54 AM.
Oct 29, 2015, 11:17 AM
#209
You adjust the pedal pedal under the dash. the rod end of the master cylinder has a jam nut on it.
I think overfilling has helped my trans as well. Since i don't have a lift, when i fill my trans, the front end is on jack stands. about 1-2 feet in the air. This way the fluid doesn't start coming out of the fill when it should, so i usually get 2.6-2.7 quarts in it, instead of the recommend 2.3 (
I think overfilling has helped my trans as well. Since i don't have a lift, when i fill my trans, the front end is on jack stands. about 1-2 feet in the air. This way the fluid doesn't start coming out of the fill when it should, so i usually get 2.6-2.7 quarts in it, instead of the recommend 2.3 (
ive seen one for the 5spd but not the 6 sadly. sounds like motul is the way to go though. in theory a lighter weight oil should run cooler as well - ie mt 85 vs mt90. if it's a high quality synthetic it shouldn't lose much if any protection at all either - is that more or less true? regardless sounds like motul is the way to go for the 6 speed... again though, I'm making probably 2/3rds the torque of most of you guys, can't imagine it to be too much of a problem for me
Oct 29, 2015, 12:45 PM
#210
judging by pedal feel and release point of clutch, i'd assume my pedal is still okay. with the car off the ground and clutch in @ idle, the wheels don't spin, so i don't think it's dragging. no clutch slippage during accel.. but i haven't checked in quite some time. hm... maybe i'm due for a checkup LOL