# official 2.5 5speed trans gear oil



## dmgraz (Jan 3, 2008)

I wanted to start this thread because their seems to be a lot of confusion with what gear oil should be used with our manual transmissions. I've done countless searches on vortex and on other mkv sites to try and find the best gear oil to use but no straight answer is given.
What I know: I've read that it is a pita to change the gear oil on the 5 speed due to the proper oil level being above the fill plug. I believe in the Bentley manual it says that the gear box takes 2 quarts (1.9qt). which means you are gonna have to measure before you fill. Bentley also says to change using VW recommended gear oil. 
Why I'd like to change my gear oil: Currently I have about 30k mi on my '08, I have a nuespeed SS, verdict motorsport bracket bushings, and 42dd end links. I dont really care about changing the gear oil but i am interested for two reasons: 1) after installing the short shift which was first i noticed that the throws because a little notchy. 2) Since i've owned the car (new), I have noticed that 4th gear at 40mph (average speed in s. florida) that the tranny has a whine/ howl. You let off the gas and it dies down, you reapply and it comes back, if you stay in fourth and drive faster than 40 it will die down. I am aware that changing the gear oil might not solve these problems but I'd rather change it than have it get worse. plus i'd like to smooth out the shifts a little bit.
This is what I have read (I do not know if any of these statements are true): 
from one site it says to use MT90 but should be used in warmer weather. Use a GL4 gear oil unless their are brass components which then a GL5 should be used. Some people use GM synchromesh but no one person has come out and said it is okay to put into a vw tranny. Most sites say to use Redline 75w90 or Amisol.
If anyone knows or wants to comment on what they have used on this transmission and which would be the best lubricant , out with it. lets make this official.










_Modified by dmgraz at 7:41 PM 12-23-2009_


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## kungfoojesus (Jan 10, 2005)

synchromesh is the best, period. try it once and you'll never go back.
i've run so many gear oils in my cars and trucks, synchromesh is unlike any of them. it works extremely hot, extremely cold, smoother shifts, quiter cooler running... etc etc etc
i've used redline mt90. it absolutely works great if you've got gear grinds at high rev's on hot hard running days. for the winter it is garbage. takes forever to warm up making your shifter feel like it is being pushed through gravel. i only use redline mt90 when i have problems with gear grinds at high rev's (6k+). it really fixed my vr6 third gear grind. it has never come back since i installed redline mt90. i don't drive it in the cold anymore either so w/e about that lil downside.
synchromesh is only like 30 weight but has additives to bring that up. it is a very strange gear oil. all i know it is miraculous in vw trannies. check the manual tranny forums to see for yourself, PLENTY of vw's run this stuff. in fact it is a common gear oil found in all kinds of cars (aftermarket). i doubt you'll find an enthusiast community or single person that says a single bad thing about synchromesh!!!! honestly i've never seen or heard a bad thing about it, ever, anywhere. the stuff is truly magic oil for gears.


_Modified by kungfoojesus at 10:26 AM 12-24-2009_


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## kungfoojesus (Jan 10, 2005)

just wanted to add, vw also has some "heavy duty" oem gear oil that is a step up from what comes in our cars from the factory. it is extremely expensive ($100 - $150) to fill my 02m with it. it also did NOT solve the gear grind problems that redline mt90 did (for $36 a fill). it was an improvement but certainly not worth anywhere near the price they charge for the stuff.
also wanted to add, synchromesh has solved gear grinds that no other oil even improved in my cars/trucks before. it also doesn't have the problems that the "heavy duty" gear oils have at cold temperatures (first few miles in the winter are real notchy/semi-grindy). the lube is smart, it like adapts to the weight you need. strange stuff very unlike conventional gear lubes, but works GREAT.


_Modified by kungfoojesus at 10:31 AM 12-24-2009_


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## dmgraz (Jan 3, 2008)

so i take it that synchromesh is probably the best stuff to use. thanks for your help. should i look at a specific weight? i live in florida so it never really gets too cold. thanks again for clearing that up.
also, which should i get: GM, Pennzoil, or Amisol syncromesh.


_Modified by dmgraz at 11:18 AM 12-24-2009_


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## kungfoojesus (Jan 10, 2005)

gm/pennzoil is what people are mostly using. i also thought it was only one weight, something like the equiv to 80 weight but it is unlike other gear lube in this respect. the weight doesn't matter so much because of how synchromesh works. i know its strange.


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## vw93to85 (May 10, 2007)

*Re: (kungfoojesus)*

Gm Synchromesh, Part number 12345349 list price of $17.35 per quart


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## dmgraz (Jan 3, 2008)

*Re: (vw93to85)*

nice, you think i should get gm's gear oil or penzoil?


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## vw93to85 (May 10, 2007)

*Re: (dmgraz)*

Don't know if ones better than the other but I sell tons of this stuff to people with all kinds of cars.


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## foolclear (Jun 27, 2008)

*Re: (vw93to85)*

i'm going to change my gear oil soon for my 08 jetta 2.5 i found a DIY site 
http://www.golfmkv.net/blog/archives/7
but its for 2.0t. can anyone confirm that its the same procedure and same tools? i only have about 30k miles but want to change anyways. since the fill level is higher then the fill plug would it be good idea to lean the car to the side so we can get 1.9 qt in without spilling or just have the car level and fill it that way>?


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## 2pt0tee (Apr 28, 2008)

*Re: (foolclear)*

That is my site. I can't confirm if the 2.5 is exactly the same but it should be similar. If it doesn't take the special bit, it is most likely a 17mm allen like the older VW transmissions.
If the fill hole won't work... you can unscrew the speedo or reverse switch from the top of the transmission and fill through there.


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## rustlerdude (Aug 13, 2007)

Bought the synchromesh today and installed it. MASSIVE difference in my 07 rabbit!!! I'm stoked....good stuff.
Will have to change it more often being that it's not synthetic like oem, but it shifts smoooooth.


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## foolclear (Jun 27, 2008)

*Re: (rustlerdude)*

hey what method did you use? just drain and put in 1.9qt? or u fill from the top? speedo or reverse valve?


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## rustlerdude (Aug 13, 2007)

I drained it and put it into the fill hole. I guess not all of it drains out because less than 1.5 quarts went back in. Maybe ill do it again in a few weeks to make sure all the old stuff is drained.


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## rustlerdude (Aug 13, 2007)

http://volkswagenownersclub.co...r-oil
I did a quick diy on there. My name is nitroscope8 on there..


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## Servo888 (Feb 25, 2007)

*Re: (rustlerdude)*


_Quote, originally posted by *rustlerdude* »_I drained it and put it into the fill hole. I guess not all of it drains out because less than 1.5 quarts went back in. Maybe ill do it again in a few weeks to make sure all the old stuff is drained. 


Because that particular fill hole is only used when the transmission it out of the engine bay. Once the transmission is mounted, the oil level is right in the middle of the fill hole. 
To empty the transmission you must remove the selector shaft journal (remember to lock the selector lever on the shifter mechanism first), and remove both the hex plugs. This will ensure everything comes out. Once emptied, you need to reinstall all of the hex bolts, then refill using the back-up light switch mounting hole.


_Modified by Servo888 at 6:20 PM 1-24-2010_


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## foolclear (Jun 27, 2008)

*Re: (Servo888)*

i already have the 17mm wrench and was going to changed the oil this week. is it acceptable if its a little low on oil that is my concern. how do you lock the selector lever on the shifter?



_Modified by foolclear at 4:21 PM 2-18-2010_


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## tspielman (Jun 25, 2007)

this looks like a pain how much does the dealer charge to do this?


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## foolclear (Jun 27, 2008)

*Re: (tspielman)*

i just changed my Gear oil today! i had 29k miles on the car, it was a pretty easy job. i had the car on ramps, and i loosen the fill plug first and i discover nothing came out of it







and i was like wtf and i suppect a leak somewhere then i undid the drain screw and waited for like 1 hour to let it all drain out. i put in 1qt of gm synchronmesh first then put in another 12 oz the it started to come out so i put the screw back in. so basically i had 44oz in it now. i still had 20 oz in the bottle so i drove around the block and came back going though all the gears. now i just got the driver side of the car on ramps this time so it was leaning to the left i thought it would take more fluid this way then i pour in most of the 20 oz and done. i didn't feel a different when driving but i felt it less notchy when just idling and shifting. i have some picture if anyones interested! 








fluid still seem good 








i opened the fill plug first and nothing came out of it 








the transmission itself was oily is this normal?


















_Modified by foolclear at 4:42 PM 2-18-2010_


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## KulturKampf (Nov 30, 2009)

dumb question and off topic but where did you get those ramps?


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## foolclear (Jun 27, 2008)

*Re: (KulturKampf)*

i apologize. please have mercy and forgiveness i'm just a car noob.
i got the ramps from Walmart FTW


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## dmgraz (Jan 3, 2008)

Should I use this stuff and add it to some royal purple or redline tranny oil? Or should I stick to gm synchro-mesh? Also conventional or synthetic? 
http://www.ecstuning.com/Volks...61605/
Is their a process to change from convetional over to synthetic or is it a staright process (any additives)?


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## DOQ fastlane (Feb 25, 2009)

*Re: official 2.5 5speed trans gear oil (dmgraz)*

Im glad i found this thread.. i think ill pick up 2 of the GM synro as well for next week.


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## foolclear (Jun 27, 2008)

use whatever you want, i would say because my tranny is leaky and it still shifts, so its all good.


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## dmgraz (Jan 3, 2008)

So i finally changed to the gm synchromesh. first impressions are: meh. feels the same no difference. probably would work better if i had a tranny that was older, im definitely glad i changed it, i could see very small metal particles probably around 50 microns (guessing). the tranny does shift slightly smoother. Next time i change it i will go with something thicker.


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