which oil to use in a 2001 MK4 5 speed manual transmission?

ringram

Member
Joined
Jul 2, 2018
Location
Winnipeg
TDI
2001 Jetta, 2001 Golf
I've been reading various threads on this and there is a variety of responses. Some people recommend the VW G50 or G52 oil, others say a multitude of other types of oils.
I changed mine and put in Royal Purple synthetic manual transmission oil.
http://www.royalpurpleconsumer.com/products/synchromax-manual-transmission-fluid/
It seems OK, but I notice that the synchromesh, especially going into 1st, could be better. The oil also seemed very thin.
I can't find the viscosity rating for the oil, but it seems more like an ATF.
What is the viscosity rating for the fluid that should be in my transmission? 75W90? GL-4? I think if I have the basic requirements, I can make a decision based on what is available to me.
 

KyleMillione

Veteran Member
Joined
Jan 27, 2017
Location
Yaphank, New York
TDI
02 Jetta, 03 Jetta
I have pennzoil synchromesh in mine and it’s shifting better than it ever has, it’s alittle notchy into 3rd but it has 300k on it, and it was much worse on the vw fluid.
 

JohnTso

Veteran Member
Joined
Jul 27, 2004
Location
Wisconsin
TDI
2003 Desert Jetta & 2015 Passat SEL
I use ACDelco Synchromesh FM (Friction Modified) and it made a world of difference in both my A3 and A4.
 

IndigoBlueWagon

TDIClub Enthusiast, Principal IDParts, Vendor , w/
Joined
Aug 16, 2004
Location
South of Boston
TDI
'97 Passat, '99.5 Golf, '02 Jetta Wagon, '15 GSW
I've also had excellent luck curing grinding issues with Pennzoil Synchromesh.
 

KrashDH

Veteran Member
Joined
Dec 22, 2013
Location
Washington
TDI
2002 Golf
I have pennzoil synchromesh in mine and it’s shifting better than it ever has, it’s alittle notchy into 3rd but it has 300k on it, and it was much worse on the vw fluid.
I use ACDelco Synchromesh FM (Friction Modified) and it made a world of difference in both my A3 and A4.
Can't go wrong with either the Pennzoil or the ACDelco. They're the goto.
I'm currently using Pennzoil, it shifts great through all of the gears and cured the notchy shifting when the OEM garbage that was in there turned to water.
 

tdidieselbobny

Top Post Dawg
Joined
Apr 4, 2005
Location
Stafford,NY (WNY)
TDI
'03 Galactic Blue Jetta TDI, '15 Silk Blue Golf Sportwagen TDI
How many quarts do you need for a drain/ refill? I bought 4 quarts of the Syncromesh, I thought it was around 2....
 

IndigoBlueWagon

TDIClub Enthusiast, Principal IDParts, Vendor , w/
Joined
Aug 16, 2004
Location
South of Boston
TDI
'97 Passat, '99.5 Golf, '02 Jetta Wagon, '15 GSW
I've now filled several 02Js with Synchromesh, including mine more than once. With the car on ramps (slight incline so the transmission should take more) I got just the two quarts in. I think the drain isn't complete enough to get 2 liters in. At least that's my experience.
 

[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
I ran honda MTF in mine
running it again in the 0A6

just because it was cheap and on the shelf
they're all light viscosity gl-4 fluids
 

2000alhVW

Veteran Member
Joined
Aug 30, 2018
Location
Silver Spring, MD
TDI
2000 Golf
Pennzoil synchromesh is just about the only gear oil typically stocked at Autozone/Advance auto.
Good gear oil doesn't exist on the shelf, and GL-4 barely exists - period. It just doesn't. Has to be ordered online or obtained through a specialty vendor.

GL-4 is unobtainium. I've pulled my hair out many times over the years trying to reach the end of the "GL4 vs GL5" mystery. There's no end to that rabbit hole, just a portal that circles you back to the beginning.

Basically, the myth goes that anything requiring GL-4 (aka ANY and/or ALL manual transmissions from 1990-2005) will not happily accept GL-5 due to the increased sulfur content which will eat away at 'yellow metals' <-- read: brass synchros.

A few of the top tier oil companies actually still have direct phone lines connected to the chemists/engineer's office. Dial the number, and you can talk with a real, legit scientist about all the nitty gritty details of whatever you want to know about different oils. Amsoil in particular offers this. I had a 15 minute conversation with one of their guys who very specifically explained the whole GL-4 vs GL-5 and specifically said "yes, GL-5 eats yellow metals, and do NOT trust the 'GL-5 is backwards compatible with GL-4' language."

Whenever I'm replacing the oil in a manual trans, it's always RedLine MT90 for me. Super high quality stuff, always cleans up a notchy trans and I don't have to worry about the GL-4 debate, even if it is $15/qt.
 

[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
motul makes a pretty cheap 90W GL-4 that we use at work,
BMW's DTF-1 is a GL-4 around that same viscosity, iirc

there are plenty of them out there, easiest way to tell? The smell. Hypoid oil (GL5) has a certain something to it that is just plain overpowering and sticks in your sinuses where GL4's stank is a good bit less pervasive, while still having a stink to it distinct from motor oil.
 

IndigoBlueWagon

TDIClub Enthusiast, Principal IDParts, Vendor , w/
Joined
Aug 16, 2004
Location
South of Boston
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'97 Passat, '99.5 Golf, '02 Jetta Wagon, '15 GSW
I've used the Liqui-Moly (we seel it too :)). It's good, but I wouldn't say it's a lot different from the G 070 VW currently sells. The good thing about Synchromesh is that it seems to help address issues with worn transmissions (difficult shifting, noise).
 

Genesis

Top Post Dawg
Joined
Feb 26, 2003
Location
Sevier County TN
TDI
'03 Jetta Wagon
Yep.

Just do NOT run a GL-5 oil in a synchronized gearbox -- ever.

If you look into the chemistry the issue is that the additive package forms a film on the various parts that is supposed to shear first, thereby protecting the metals. The problem is that GL-5 lubricants form a film that is *stronger* than the brass in the synchros, so THEY shear first! Exactly backwards compared against what you want.

GL-5 is superior (by quite a bit) in an open diff or other gearbox where there are no clutches (other than a roller locker, which is typically all steel.) But you can't use it in a synchronized transmission unless you want to replace the synchros 50,000 or so miles later.
 

52172

Veteran Member
Joined
Oct 5, 2007
Location
Buellton, Ca
TDI
2001 Golf TDI GLS
My golf has mega miles so I’m gonna go with penzoil synchromesh. Or another gl4 synchromesh. Thanks guys.
 

Powder Hound

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Joined
Oct 25, 1999
Location
Under a Bridge, New Hampshiyuh, USA
TDI
'00 Golf 4dr White 5sp, '02 Jettachero 5sp, Wife's '03 NB Platinum Gray auto(!)
Time to muddy the water: Redline MTL!! Unless it is quite worn, in which case MT-90 might be better.

Seriously, if synchromesh works for you, then good on 'ya.

Cheers,

PH
 

Genesis

Top Post Dawg
Joined
Feb 26, 2003
Location
Sevier County TN
TDI
'03 Jetta Wagon
I like the Redline MTL in my Mazda's gearbox..... has worked very well in terms of shifting performance. I can't see a reason not to run it in the VW next time it needs changed.
 

03TDICommuter

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Dec 8, 2016
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So. Cal
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03 Jetta Sedan
I just changed mine using G070 I bought from IDParts. Shifts fine in So. Cal weather and even during gridlock when it was 90 degrees out.
 

scurvy

Good Ol' Boy
Joined
Feb 21, 2006
Location
Chicago IL USA
TDI
2006 Golf
I seem to go back and forth between G070 and Pennzoil Synchromesh in mine every few years. Both work very well. Realign your shifter linkage once in a while, too.
 

Powder Hound

Top Post Dawg
Joined
Oct 25, 1999
Location
Under a Bridge, New Hampshiyuh, USA
TDI
'00 Golf 4dr White 5sp, '02 Jettachero 5sp, Wife's '03 NB Platinum Gray auto(!)
ATF might work in a pinch, but you really want the Redline MTL that has the additives for synchronizers that ATF is not optimized for. I believe that the AFT qualifies as a gl-4 lubricant, but the MTL is better suited for the manual transaxle application.

Cheers,

PH
 

GlacialFlower

Active member
Joined
Jul 19, 2019
Location
Texas
TDI
2002 Golf GLS
To the original poster regarding Royal Purple:

I used it in my Cummins 5-sp. The guy that rebuilt the tranny said it hardens the felt something or others. Don't use it.
 

unorganizedplan

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Apr 17, 2013
Location
Okotoks, AB
TDI
2012 JSW Highline w/DSG ; 2003 Jetta ALH w/5spd
2.1 to be exact right?
2.138 L to be exact :)

I just did mine a couple weeks ago. Car on ramps, drain and fill plugs removed, and left to drain overnight.

On-hand I had 1 bottle of Penzoil Syncromesh, and 1 bottle of Amsoil 75-90 MT Gear Lube. I used a universal bottle pump (like a big hand soap pump) and pumped both bottles into the fill hole after replacing the drain plug. Both went in and no overflow drips yet . . . so searched the garage and found some old bottles of Lucas HD oil additive - a few pumps of this and finally the fill hole had some overflow.

I got out as much of the actual MT fluid from the bottles before using the Lucas, to minimize how much of it was needed. After all said and done, with all 3 bottles turned upside down into one . . . there were exactly 700mL remaining.

946mL x 3 = 2838mL
2838mL - 700mL = 2138mL (filled into the trans)

All that aside, the trans shifts just fine now. I have no idea how old the previous fluid was, or what it was . . . but it is noticeably smoother now.
 

Votblindub

Veteran Member
Joined
Dec 22, 2010
Location
NY
TDI
MK4 Jettas: Sedan & Wagon
When I bought my wagon, I shortly replaced the trans fluid in that 5 speed using OEM fluid from VW and drove it around. It was shifting just fine to begin with, but it kept shifting just great.

Now there's a 6 speed in it and it has Syncromesh in it. I haven't driven it around just yet, but from what I read online, on here and from what Frank06 and I talked about, it was a good fluid to run. This thread also reassured me that I've got the right goo in there.

Just a word of caution too, make sure you're not going with some kind of a race application fluid for a daily car. They may have excellent specs and you might find some on sale, but just keep in mind that the operating temperatures should be for the area you live in as well as the application. I almost made the mistake of dumping a bunch of racing fluid in my Audi diffs when doing the service recently. I would have grenaded my front and rear diffs this winter.
 
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