What's in your Transmission?

[JesusJones]

So I just did a fluid change in my girlfriends jetta and the manual was very specific about using gl4 rated fluid.

After looking around almost every transmission oil is gl5 rated nowadays. The Castrol syntec that's in my tranny is gl5 and our manuals say to use gl4 or gl5 and that got me wondering if there was a preference between the two?

It's near 60k on my oil and I never fully drained the original oil when I refilled it. Just pulled the axle while replacing seals and it naturally drained a little bit then refilled it. This will probably be the last time I change it so I wanna put something good in.

So what oil is in your transmission(brand weight g4 gl5)? How do you like it? Hows the cold shifting? And what kinda mpg's are you getting with it?

Mines catsrol syntec 75w-90 gl5 Once its warm it shifts real nice. Never get any grinding and it feels smooth and healthy. In the cold (sub zero) it is a different story. I need to wait a moment or two for it to pop into gear without forcing it but no grinding as long as you don't force anything. As for mileage I've normally gotten around 35 mpg highway with this stuff. But like I said it's on its way out.



Cheers,

[speedy25]

VERY discussed topic in the car world. Biggest problem is brass synchros DONT like GL5 oils. Best bet is buy whatever the OEM has for the car. 2nd best despite the cost is redline or royal purple.

Despite reading that advice over and over I have Pennzoil synchromesh. My corrolla seems to like it well, with no changes in shiftability between cold and hot.

-SP

[Kiwi-Corolla]

I use Valvoline DuraGear 75w-90 GL-5. Never had a problem since I changed it 13,000km ago. Shifts smoothly when cold (although the temps don't get very cold where I live) and I average about 37mpg if I don't get heavy on the accelerator.

[sequoiasoon]

I had used multiple different fluids trying to fix a light grind (synchro's not meshing) but mostly at higher RPM's.

Fixed the problem with BG SynchroShift II on recommendation of a friend. They used it all the time at the BMW dealer he worked at for the same reason. It's a 75W-80 GL4. Car shifted great cold or hot. On an easy highway cruise (65 mph max because of cops) I was getting 41 mpg with almost 200k on the car. Average was low/mid 30's but that was a lot more around town and higher RPM shifting.

It wasn't cheap ($15-$20/qt) when I got it but since it cleared up my grinding that 3 shops said would need rebuild to fix I was happy with it. I changed it every 2 years after that with same stuff just for good measure. Smooth shifting with no grind was worth $60 every 2 years.

http://www.prostreetonline.com/x/bg-synchroshift.asp

I was able to get many of the BG products at local dealerships (Toyota, Infiniti, Lexus, Honda) but had to ask for it at the parts window. Got some strange looks on the request. Many use it for the in house services but not on shelves for sale.

Also get some of the BG 44K fuel system cleaner. Do 2-3 tanks with a can in each. Puts the store brand Techron stuff to shame.

[ganda1f]

Drained my tranny 3 years ago. Filled with Redline MT-90 75w-90 GL4. That was 110,000kms ago. Never had any problems with the transmission. Shifts smooth regardless of temperature. Tested between -15C to 35C.

[BoyYota]

You guys make me wanna go put some quality fluid in my auto.

[Rich L]

Best I have found is Redline MT-90 75W90 GL4. $10 a quart at Knechts Auto Parts.

[sequoiasoon]

The reason I went with the 75W-80 was because what they determined at BMW was the slightly thicker fluid was putting that extra little drag on the synchro's at higher RPM causing them to slow down too fast. The problem they described was light grind just like I had and all of them had done multiple fluid changes with different brands (all factory recommended weight) in dino and syn. When they started using the BG all the issues went away just like mine. Maybe in hotter temps it's OK but when colder I had more issues that the BG cured.

[JesusJones]

Sorry for the delay, thanks for all the responses guys. I've heard of redline and looked into buying some. Costs around 16$ per liter here. Which is a higher price than what I can get oem fluid for a jetta which is gl4 and 75w-90 and apparently a lifetime fluid that never needs changing(which is questionable)

Bg synchroshift I've heard of but is expensive and I don't know of anyone that sells it here.

I'm leaning towards redline (or the oem VW jetta stuff since I have a full bottle already.) Since I'm not really looking to fix a grinding issue just prevent a grinding issue. For now though I'm gonna focus on what going on with my clutches hydraulic system. But that is an issue for another thread.

Anyways thanks for the replies guys, When the day comes that I do change my tranny oil I'll post up some pics of how the castrol looks after 60K and my opinion on how the new stuff turns out.

Cheers!

[Suprawillis]

FWIW, my 3rd gear synchro has been gone the last 200k miles and I have been shifting from 2nd to fourth like a boss. However, I have many a car, and many a different fluids lying around in my garage.

I have tried redline MT-90, royal purple synchromax, penzoil synchromesh, AMS synchromesh, GM synchromesh, and good ole' 10w30. With good ole' 10w30, I can get it into 3rd gear every once in a while. Like once in every 5-7 attempts. With any of the afformentioned above fluids minus the good ole' 10w30, it would NEVER go into 3rd gear. Just my experience.

[JesusJones]

Alrighty so with the warm weather here my shifting really started getting notchy/clunky. Not grinding but it didn't feel like I was cutting through butter anymore. And the car would actually shift better cold than warm!

So I started looking back into fluids for the tranny. I was VERY VERY tempted to put in g060 VW OEM oil. It is a gl4 oil but the viscosity is mystery. And most likely is around 6.4 cst @ 100c versus the 13-15 cst @ 100c it should be. G050 VW oil was a true 75w-90 but this oil is no longer made and it seems VW has moved to lighter oils in the fight for highest mpg claims in the car sales world. ANYWAYS!

Our trannies can use gl4 or gl5, but after extensive reading it seems that gl4 synthetic or good ol Dino oil provides the best shifting for these cars. And if you are going to get gl-5 make sure it has NO LSD additives and it should also be fine.

Red Line was my first pick but after extensive reading I decided it might not be the best oil. Something about bearing failures and that red line isn't really a certified oil (API, ACEA etc). That was enough for me to stay clear.

As for BG synchroshift II I can't get it locally and it is apparently a lighter weight oil so I also didn't bother with that either.

So all I could really find in gl4 was pennzoil synthetic 75w-90. It wasn't really cheap either at 17$ per bottle. But it should last at LEAST another 30k so I don't mind paying the bit extra. Shifting is back to being smooth and normal (as expected with putting in any sort of new fluid). The old fluid after 30K was a dark honey brown so it was due for the change.

As for this new fluid only time will tell how it holds up. But I can say without a doubt that this fluid will make your MT happy and you won't have shifting issues after putting it in. MPG status TBA...

Cheers

[speedy25]

Add another one to the list- I have Pennzoil Synchromesh in my cars. They seem to work very well. The used trans I have in my car shifts very smooth even into first while moving. This is on a trans that had 145k miles on it when I pulled it at the junkyard.

-SP