Brand new rebuilt trans from Subaru and 4th has grinded off and on since day one. Today it drove me crazy enough to look it up and as usual with these cars, EVERYONE HAS THE SAME PROBLEM and it was widespread enough that Google autocompleted my text while searching. Going to give this a shot. Next will be the squeaky clutch pedal fix (brace that goes under the dash above the pedal fix made my old wrx feel better than it ever did) thanks for the info sir!
Here's the deal, the synchros in our transmissions need friction modifiers to operate correctly, like a lot of other trans do. Amsoil is great gear oil, but it does not contain any friction modifiers, so it's just slick as owl shit and won't allow the synchros to engage correctly. That's where the red line fluid comes into play, it does have the friction modifiers, so you could probably just add a bottle of it to any brand gear oil and it would work. I've used uncle scottys cocktail for almost a decade now without any problems, but I might just try the andrewtech blend next time. Then again, amsoil is a really good product! Maybe I'll try my own concoction?
I am having a 4th gear grind as well in my 16' STI whenever I downshift from 5th to 4th and when shifting from 3rd to 4th above 4k rpms. The dealership recommended replacing the clutch and slave cylinder because of some wear. I may try this cocktail before dropping 2k on a new clutch
Swepco201 gear oil is the answer to all of your issues. That Smurf blood will sludge up eventually. Keep your fluids changed regularly and you don't have to pay through the nose for lubricants.
All right I just got to be clear on this for educating everyone. The severe gear oil version of the 75w90 amsoil is meant for your differential not your transmission. If you're adding amsoil make sure you get the non-severe gear oil 75w90 version for your transmission. Problem solved, if you call amsoil they will tell you this exact thing vs watching TH-cam.
@@BoltsNBoostI shot them an email concerning the differences years ago. But yes they should definitely add that to the website it does not like playing with the dccd. I run the severe in my diffs and the normal amsoil 75w90 in the trans. Both VA and VB STI swapped. Zero issues. Ones an 15 STI trans and the others a 18 STI trans
I am running the red line oil in my MR2 and really like it. So smooth and buttery. Heard lots of back and forth on internet as well. Decided to try it and have had no issues.
I was also grinding with all motul 300. WIth medium to heavy throttle. there was a few guy recommending all Lightweight Shockproof. I was Skeptical Let me tell you that its amazing! It even shifts into gear soooo much smoother. Side note on the STI's with internal pumps, they say the pumps are not needed and the design is the same on the new transmissions. I haven't heard any complaints using the Lightweight shockproof on those transmissions either
My VA2 15 sti does that same grind. I did the exact same thing and used amsoil. Gonna try this cocktail. Been reading up on this for about month now. Gonna try it
What about grinding in the lowest gear my 13 wrx only grinds in 1st gear other than that the rest of the gears are fine except reverse also is sticky and never wants to go into gear as well.
Hey man, thanks for making a vid on this! I’ve been curious for a long time and didn’t realize the answer was right here. I did the Andrew tech cocktail a few months back and it worked STELLAR. Night and day difference. After a few months though, now the grind is back…think it could be the two fluids separating themselves in the tranny? Or think it’s just time to do another swap?
The issue is... its more of a band aid OR somewhat of a fix if the synchros are on the verge... but in the end I'd still think that the synchros need fixed. It shouldn't be back in a couple of months... unless you put like 5 to 10k km on it.
This 4th grear grind just happened to me. I however know my fluid is in fact over due for a change cuz I’ve been putting off. You think a simple fluid change would correct this or should I try this cocktail
I heard good things about redline 75w90 ns. I was going to try AMS oil severe gear but I’m nervous after this. I’m currently using the general Gl5 redline 75w90 and have noticed notchy shifting and have only grinded gears briefly in random instances into 2nd.
@@BoltsNBoostwent to Andrew Yates the originator of the cocktail he recommended me to run straight Redline shockproof so I did and it’s great! And I run Motul 90PA in the rear diff.
I have a 2016 sti and my 1st gear once in a while it will rattle… it’s so annoying my car only has 87k and I am the second owner… so idk if it was the previous owner that was hard on it or if it’s because got new transmission oil ?
I’m scared to try this , I’m being told the redline is a temp fix and could clog the pump over time bc it’s not mad for our transmissions .. any advice? So much conflict:/ 2017 STI here
Thanks! Definitely could help avoid the issue and help assist it in lasting. Some people claim that it can "fix" some synchro issue. Once a grind is there...its usually due to synchro wear or clutch. Make sure this cocktail you are able to use in a 2021... also check/bleed clutch.
my 2019 sti trans grinds 2nd on cold start and drive. do you think this will help. also my trans feels pretty notchy. I am now using motul with no luck.
I'm getting a notchy shift into 2nd in 2017 wrx. Hoping to find a solution with a fluid swap because we cracked the trans and looked at it and everything looked great in there...so not sure why it's having this issue.
@@BoltsNBoost yeah already ordered it so I'll give it a try. The fluid in there now is just standard subaru brand so this should be a better oil than that at least.
@Chris Lane fluids might have helped smooth it out a little. I also put a shift stop in as well a heavy shift knob and new solid shift linkage bushing. Still not perfect, but it goes into gear easier now.
I would use straight motul 75w90 myself. That is what I used in my 2005 STi. Or if you can find some at your local dealer... Extra S OEM fluid. I don't have the luxury as my local dealer doesn't sell it to public I don't think.
I was able to find some at my local performance shop, but really any good gear oil will be fine just mix in some of the lightweight shockproof as a friction booster and you’re good.
Been running the cocktail for 20k miles. My grind never came back. 630hp rotated
Nice!
Did this, never turning back.
Great stuff, 4th gear is a dream again.
Just did mine 2 days ago after watching your video. 2018 wrx 300whp was starting to grind from 2nd to 3rd. Grind is gone! Thanks a lot 🤙🏾
Glad it helped!
would it grind at high rpm’s? i’m having the same issue it only grinds going 2nd to 3rd over 4k rpms
when your grind came, did you do it asap?
Brand new rebuilt trans from Subaru and 4th has grinded off and on since day one. Today it drove me crazy enough to look it up and as usual with these cars, EVERYONE HAS THE SAME PROBLEM and it was widespread enough that Google autocompleted my text while searching. Going to give this a shot. Next will be the squeaky clutch pedal fix (brace that goes under the dash above the pedal fix made my old wrx feel better than it ever did) thanks for the info sir!
Happy to help! Hopfully it works for you
Two Lightweight Shockproof and 2.5 Redline 75w90 NS worked for me. I can say Lightweight Shockproof does work.
Agreed!
Here's the deal, the synchros in our transmissions need friction modifiers to operate correctly, like a lot of other trans do. Amsoil is great gear oil, but it does not contain any friction modifiers, so it's just slick as owl shit and won't allow the synchros to engage correctly. That's where the red line fluid comes into play, it does have the friction modifiers, so you could probably just add a bottle of it to any brand gear oil and it would work. I've used uncle scottys cocktail for almost a decade now without any problems, but I might just try the andrewtech blend next time. Then again, amsoil is a really good product! Maybe I'll try my own concoction?
Yep. Good summary 👍
Straight lightweight shockproof works great as well! I have heard that works better than the cocktail on reducing wear on high 700whp+ applications
I am having a 4th gear grind as well in my 16' STI whenever I downshift from 5th to 4th and when shifting from 3rd to 4th above 4k rpms. The dealership recommended replacing the clutch and slave cylinder because of some wear. I may try this cocktail before dropping 2k on a new clutch
Have u tried this cocktail yet?
Ill let u know replacing the clutch assy wont solve it anyway 🤫
Swepco201 gear oil is the answer to all of your issues. That Smurf blood will sludge up eventually. Keep your fluids changed regularly and you don't have to pay through the nose for lubricants.
Currently running 100% Motul in the trans now, but will be changing it to run a 50/50 mix for the next change! (Redline shockproof/Motul 300)
Yep. That's what I did too. Works phenomenal.
All right I just got to be clear on this for educating everyone. The severe gear oil version of the 75w90 amsoil is meant for your differential not your transmission. If you're adding amsoil make sure you get the non-severe gear oil 75w90 version for your transmission. Problem solved, if you call amsoil they will tell you this exact thing vs watching TH-cam.
How about their website? That says to use severe gear?
@@BoltsNBoostI shot them an email concerning the differences years ago. But yes they should definitely add that to the website it does not like playing with the dccd. I run the severe in my diffs and the normal amsoil 75w90 in the trans. Both VA and VB STI swapped. Zero issues. Ones an 15 STI trans and the others a 18 STI trans
I am running the red line oil in my MR2 and really like it. So smooth and buttery. Heard lots of back and forth on internet as well. Decided to try it and have had no issues.
Yeah agreed. So far, it's magic sauce. 🎩
I was also grinding with all motul 300. WIth medium to heavy throttle. there was a few guy recommending all Lightweight Shockproof. I was Skeptical Let me tell you that its amazing! It even shifts into gear soooo much smoother. Side note on the STI's with internal pumps, they say the pumps are not needed and the design is the same on the new transmissions. I haven't heard any complaints using the Lightweight shockproof on those transmissions either
For some reason...it seems like the newer trans are more susceptible to grinding
@@BoltsNBoost yeah even though the carbon syncros should be better. They did cheap out some other
Parts of the design on the newer STI Transmissions.
No more internal oil pump to cool down ...
My VA2 15 sti does that same grind. I did the exact same thing and used amsoil. Gonna try this cocktail. Been reading up on this for about month now. Gonna try it
Good call!
any updates ?
Bueno??
Try using the GM synchromesh fluid, it is magical stuff
What about grinding in the lowest gear my 13 wrx only grinds in 1st gear other than that the rest of the gears are fine except reverse also is sticky and never wants to go into gear as well.
Did you try the cocktail?
Hey man, thanks for making a vid on this! I’ve been curious for a long time and didn’t realize the answer was right here. I did the Andrew tech cocktail a few months back and it worked STELLAR. Night and day difference. After a few months though, now the grind is back…think it could be the two fluids separating themselves in the tranny? Or think it’s just time to do another swap?
The issue is... its more of a band aid OR somewhat of a fix if the synchros are on the verge... but in the end I'd still think that the synchros need fixed.
It shouldn't be back in a couple of months... unless you put like 5 to 10k km on it.
This 4th grear grind just happened to me. I however know my fluid is in fact over due for a change cuz I’ve been putting off. You think a simple fluid change would correct this or should I try this cocktail
Usually when a synchro starts.. its now a problem.
I heard good things about redline 75w90 ns. I was going to try AMS oil severe gear but I’m nervous after this. I’m currently using the general Gl5 redline 75w90 and have noticed notchy shifting and have only grinded gears briefly in random instances into 2nd.
Yeah I tried all of the above. This was the only contraption that didn't encourage a grind.
@@BoltsNBoostwent to Andrew Yates the originator of the cocktail he recommended me to run straight Redline shockproof so I did and it’s great! And I run Motul 90PA in the rear diff.
Any leads on that motul 75w90, I've been backordered since April and I'm about to just cancel my order and run the Bader cocktail
Try Amazon. That's where I got these I think
I just ordered the Bader cocktail 50/50
I have a 2016 sti and my 1st gear once in a while it will rattle… it’s so annoying my car only has 87k and I am the second owner… so idk if it was the previous owner that was hard on it or if it’s because got new transmission oil ?
Was the cocktail used on the hatch? (Ottawa)
Yes it was.
I’m scared to try this , I’m being told the redline is a temp fix and could clog the pump over time bc it’s not mad for our transmissions .. any advice? So much conflict:/ 2017 STI here
I dont think it's good for that year due to what you mentioned. But i have ran it on older cars without issues.
@@BoltsNBoost thanks man , going to ask the shop what to do , going to hold off of now
What about for the rear diff
That's also on my channel.
Very informative video 💯. I’m having some resistance going into 1st and reverse on my 21 sti, could this cocktail potentially solve the issue?
Thanks! Definitely could help avoid the issue and help assist it in lasting. Some people claim that it can "fix" some synchro issue. Once a grind is there...its usually due to synchro wear or clutch. Make sure this cocktail you are able to use in a 2021... also check/bleed clutch.
This be ok to run in a 2018 wrx six speed?
Unfortunately I have no idea. Never owned one past 2013. I don't think it does work due to an internal pump.
Do you think Lucas oil can fix it a little curious.
Im deciding to do this in my 09 wrx. very notchy and hard to shift and slight grinding. do you know if the 09 wrx 5 speeds have internal pumps?
I don't think they do. But confirm for sure... the shockproof isn't the best for internal pumps.
Thoughts on running 100% lightweight shockproof?
I personally wouldn't. Some do and swear by it.
my 2019 sti trans grinds 2nd on cold start and drive. do you think this will help. also my trans feels pretty notchy. I am now using motul with no luck.
Straight motul made mine worse
Do you know if a 07 spec b 6speed has an internal pump? Having the same issue on mine. Planning on trying the andrewtech cocktail
I'm not aware unfortunately. Definitely try to check if it does. This stuff works!
@@BoltsNBoost ok I have motul gear 300 in it rn. I was just going to drain it all or do you think I could just drain some then add the redline in?
@@emeryman92 depends how old.
@@BoltsNBoost True I will let u know my results. Just gunna flush it I think since they say to add the redline 1st
The cocktail worked! Did it on Friday. No more 4th gear grinds so far
Would this work in the 5 speed, having a small grind in 3rd until its warm 🤔
I now made it to the end of the video and see you said try it on the 5 speed also 😂 sorry
How has yours been holding up? I have a grind going into 3rd unless I shift slow.
I'm getting a notchy shift into 2nd in 2017 wrx. Hoping to find a solution with a fluid swap because we cracked the trans and looked at it and everything looked great in there...so not sure why it's having this issue.
I think you are able to use this cocktail... confirm tho. If so, I'd try it
@@BoltsNBoost yeah already ordered it so I'll give it a try. The fluid in there now is just standard subaru brand so this should be a better oil than that at least.
@@thereignofthezero225 how did this work for you man?
@Chris Lane fluids might have helped smooth it out a little. I also put a shift stop in as well a heavy shift knob and new solid shift linkage bushing. Still not perfect, but it goes into gear easier now.
@Chris Lane ...apparently now all of a sudden my windshield wiper fluid tank is cracked though smh. So tired of throwing money at cars
So how often would you recommend to change the fluid out with this cocktail mix?
All depends. I'm not a professional but I would go by feel and inspection. I'd probably change every season. But that's just me.
@@BoltsNBoost and for the rear differential you just use plain 75w90?
What can I use in my 05 sti if it has an internal pump?
I would use straight motul 75w90 myself. That is what I used in my 2005 STi. Or if you can find some at your local dealer... Extra S OEM fluid. I don't have the luxury as my local dealer doesn't sell it to public I don't think.
I have a 2012 wrx with the 5 speed and i have the same problem do you think this will work onn mine?
Not entirely sure. I beleive it would as it shouldn't have an internal pump... but confirm that. I always had STis
How about below freezing point living in canada will this be okay?
That's me lol
Would this work on a 2008 g37s 6 speed. My 5th gear grind is killing me please help
No idea. But generally the shock proof works well to fix such issues. As long as there is not an internal pump in transmission.
hhhm every where i go it says the motul 300 75w90 has been discontinued. what should we use now?
I was able to find some at my local performance shop, but really any good gear oil will be fine just mix in some of the lightweight shockproof as a friction booster and you’re good.
@@messybuilds54 Yea, I ended up going with Torco and its been amazing.
Can use Castrol syntax 75w90 Universal plus + redline light proof?
I have this issue :/
Can I run this mix in my 06 WRX?
Can try it. Some people have success some don't. Use at your own risk and always look into it.
Works for 5th gearbox on 99 gc8?
Couldn't tell you. I'm sure if you google "Scottys cocktail in X " car it should show results.
@@BoltsNBoost can't find this info. 6rh gear yes.. but old gc8 5rh... Not find information about the cocktail
my manual gearbox sometimes grinding little bit on higher rpm. what u think this cocktail fix grinding? (sry for bad english)
Can't hurt to try it. I'd just make sure people have done it as some trans don't like the shockproof due to internal pumps