Urgent Gear oil question

[Brett Dikeman]

On Feb 13, 2008, at 10:20 PM, Bernie Benz wrote:

> Don’t use GL-5 in the gear box, use GL-4. GL5 won’t harm the gears

SOME GL-5 fluids are compatible.  Some are not because they contain  
additives used to get the GL5 rating which are not compatible with  
brass. Consult with the manufacturer and specifically ask if it is  
compatible with VW/Audi transmissions.  Mobil 1, Amsoil, and others  
have hotlines specifically for compatibility/application questions.   
Several have email addresses as well.

>  but will result in slow shifting, as it is designed for hypoid
> gearing requirements, the final drive systems.

GL4/5 are different performance standards, and while GL5 fluids are (I  
think) always hypoid compatible, so are many GL-4 oils.  You're also  
not using the term "final drive" properly; final drive refers to the  
halfshafts and wheels, not the rear differential or transmission.

> Before you top up with GL-4, add a bottle of snake oil, engine oil  
> stop leak, to the tranny
> to eliminaate and stop future rotary shaft seal leaks.

The most common seal leak is the passenger front side output shaft  
seal, and it's because of heat from the exhaust downpipe.  Stopleak  
won't fix a seal that is damaged from heat exposure or aging.  It may  
stop the leak temporarily, but emphasis is on "temporarily." It's all  
the more likely to cause a more significant or sudden failure later  
on, which would be both very expensive and very hazardous if it  
happens at speed.

> On Feb 13, 2008, at 6:55 PM, John S. Lagnese wrote:
>>
>> I am low on gear oil. The Bentley is of no use as usual.

The Bentley does in fact list the oil specs for both transmission and  
rear differential.

>>  What do I need in my 5 speed gearbox for my 91 200 20V Quattro?

The simple answer: get the Audi fluid from the dealer, or if you need  
to save some $, get it from Clair Parts Express or similar dealer  
wholesale source.

Brett