GL-4 transmission oil

[Brett Dikeman]

On Sep 19, 2005, at 4:57 PM, William Magliocco wrote:

> You are correct, George.  I purchased Sta-Lube (CRC)
> GL-4 gear oil at NAPA here in ATL.  I have also used
> the synthetic Red Line GL-4 specific product, which
> was purchased from ye olde EuroPartsHaus...
>
> Good luck finding a REAL GL-4 gear oil at the chain
> stores, or Nazi*Mart.

That's because there is no real reason to prefer GL4 over GL5 if you  
are careful (read on.)  The problem was that additives in some GL5  
fluids were not compatible with brass syncros used in VW, Porsche,  
and Audi transmissions.  GL4 doesn't mean "does not eat brass", nor  
does GL5 mean "will eat brass".  They are specification, and it was  
just coincidence that the additives used by oil manufacturers for  
meeting GL5 were not brass compatible.

Amsoil and a few others have long since reformulated their GL5 oils  
to be compatible with brass syncros.  Some will specifically mention  
this- others, you'll have to contact their customer service  
departments to see, because NOT EVERYONE has done so; MAKE SURE YOU  
ASK.  If they say in writing it's OK for a VW transmission with brass  
syncros, everything's kosher.  If it's not, they just bought you a  
new transmission, because they told you in writing it was OK.

That said, the VW/Audi transmission fluid is perfectly good (just not  
"lifetime" like Audi claimed) and there are few reasons anyone should  
waste time or money on anything else.  Redline on the other  
hand...when I was searching for info about Redline, Amsoil, etc- I  
kept running across sad stories that started with "filled with  
redline" and then ended with "blown transmission".  This was not true  
of any other fluid.  That said, it is hardly conclusive; maybe  
Redline was used to try and "fix" what was really a bad transmission  
on the verge of dying and it was a matter of time- sorta like  
sticking a bandaid on a dam to fix a pinhole leak and then when it  
bursts, blaming the bandaid...maybe Redline appeals to a "certain  
crowd" that is rather tough on their transmissions...who knows.

Brett
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