Just changed Tranny fluid, GL4 to GL5...

[unDummy]

The issues are with temperatures AND moisture.

The GL4 and GL5 additive packages are the similar except in different concentrations. GL4 will do the same damage but take a little more time.

This is one reason why I push the 2-3yr/
I have no problem using GL5. Ford GT owners require it. Subaru required it. Its an FSM option with all my previous Nissans/Mazdas too.

GL4+ fluids are GL5 without the scary label.

 

[SOHCman]

Originally Posted By: unDummy
The issues are with temperatures AND moisture.

The GL4 and GL5 additive packages are the similar except in different concentrations. GL4 will do the same damage but take a little more time.

This is one reason why I push the 2-3yr/
I have no problem using GL5. Ford GT owners require it. Subaru required it. Its an FSM option with all my previous Nissans/Mazdas too.

GL4+ fluids are GL5 without the scary label.


It may be true that some transmissions are "designed" for the use of GL-5 probably due to a lack of yellow metals and other considerations. But even if a manufacturer specs gl-4 "or" gl-5 its likely to shift better with the GL-4 and may only spec GL-5 for when in a pinch.

Conversely I would never put GLl-4 in a differential.

 

[Da Game]

Originally Posted By: unDummy
You can add a bottle of Lubegard Gear Oil Supplement to assist.



Can Lubrgard Gear Oil Supplement be used in the differentials? Also why Lubrgard and not Amsoil or Torco products?

 

[salv]

I TRIED A GL-5 IN MY TRANNY FOR A WHILE, BUT IT WAS WAY TOO SLICK FOR THE SYNCHROS. I SWITCHED IT OUT FOR BG SYNCHROSHIFT II GL-4. WOW! THE CAR DIDN'T SHIFT THIS WELL WITH THE FACTORY FLUID IN IT.

 

[mechtech2]

Even though most modern GL-5 lube is buffered, it still has sulfur.
So it is not corrosion that is the problem , directly.
It is the flaking off of chunks under load, which are strongly bonded and take metal the with them.

It is smart to minimize any sulfur in manual trans lube.
Any application with yellow metals.

 

[scurvy]

Originally Posted By: GLISHO
Anything I can add to minimize this?


There's a vendor on TDIClub who swears by the Lubro-Moly 75w90 GL5 gear oil and has an apocryphal story about an aftermarket transmission builder who claims it's the best thing since sliced bread.

Personally I would not run a GL5 gear oil when so many fine synthetic GL4 options are available - in this case you might try Red Line MTL, although I have heard it's long-term not great for the synchros, a bit too slippery. I've used MTL and a 50/50 mix of MT90 in both my TDIs.

What I heartily recommend now (and what I run in mine, and is a definite upgrade over the Red Line fluids) are the newer synthetic gear oils available from VWAG, either G060726A2 (slightly thicker) or G070726A2 (slightly thinner). With the hopped up 1.8T in your warmer temps I would reckon the former should probably do nicely for you.

You should also realign the shifter linkage - that alone may help significantly.

 

[GLISHO]

Haven't looked at this in a while but speaking of that "aftermarket trans builder" who swears by it, I think I know exactly who you're talking about (I'm from Chicago and I see you are too!). If its M1 in Glenview, I've argued with him about this for a while as well. He's been putting that same Lubromoly GL-5 in peoples GL-4 Spec VW trannies for God knows how long now and swears its just fine, and swears I'm the only one complaining about it. Regardless, I've been running GL-4 Redline MT-90 for about 3-4 months now and LOVING it. MUCH better than that GL-5 [censored] I had in there which was a HUGE mistake.